From b6288ee12b7b2dddeb97fe9624f9d90e3c5c217f Mon Sep 17 00:00:00 2001
From: Alex Bobrikovich <abobrikovich@gmail.com>
Date: Fri, 24 Jun 2022 15:55:52 +0200
Subject: [PATCH] Add code quality tools (#42)

---
 CHANGES.md                                    |   4 +
 build.gradle                                  |   2 +-
 example-app/src/main/AndroidManifest.xml      |   1 +
 .../main/java/com/hcaptcha/example/App.java   |  26 ++
 gradle/config/checkstyle.xml                  | 385 ++++++++++++++++++
 gradle/config/cve.xml                         | 113 +++++
 gradle/config/findbugs-exclude.xml            |  30 ++
 gradle/config/pmd.xml                         |  18 +
 lombok.config                                 |   5 +
 sdk/build.gradle                              |  62 ++-
 sdk/src/androidTest/assets/hcaptcha-form.html |   3 +-
 .../java/com/hcaptcha/sdk/AssertUtil.java     |  37 +-
 .../hcaptcha/sdk/ExampleInstrumentedTest.java |   7 +-
 .../sdk/HCaptchaDialogFragmentTest.java       |  66 +--
 .../sdk/HCaptchaHeadlessWebViewTest.java      |  15 +-
 .../sdk/HCaptchaStateTestAdapter.java         |   7 +-
 sdk/src/main/assets/hcaptcha-form.html        |   7 +-
 .../main/java/com/hcaptcha/sdk/HCaptcha.java  |  45 +-
 .../com/hcaptcha/sdk/HCaptchaDebugInfo.java   | 134 ++++--
 .../hcaptcha/sdk/HCaptchaDialogFragment.java  |  22 +-
 .../java/com/hcaptcha/sdk/HCaptchaError.java  |   9 +-
 .../com/hcaptcha/sdk/HCaptchaException.java   |   1 +
 .../hcaptcha/sdk/HCaptchaHeadlessWebView.java |  20 +-
 .../com/hcaptcha/sdk/HCaptchaJSInterface.java |   1 +
 .../java/com/hcaptcha/sdk/HCaptchaSize.java   |   1 +
 .../hcaptcha/sdk/HCaptchaStateListener.java   |   6 +-
 .../java/com/hcaptcha/sdk/HCaptchaTheme.java  |   1 +
 .../hcaptcha/sdk/HCaptchaWebViewHelper.java   |  15 +-
 .../main/java/com/hcaptcha/sdk/IHCaptcha.java |   8 +-
 .../com/hcaptcha/sdk/IHCaptchaVerifier.java   |   1 +
 .../hcaptcha/sdk/tasks/OnFailureListener.java |   4 +-
 .../hcaptcha/sdk/tasks/OnSuccessListener.java |   4 +-
 .../java/com/hcaptcha/sdk/tasks/Task.java     |   8 +-
 .../com/hcaptcha/sdk/HCaptchaConfigTest.java  |  13 +-
 .../com/hcaptcha/sdk/HCaptchaErrorTest.java   |  10 +-
 .../hcaptcha/sdk/HCaptchaExceptionTest.java   |  15 +-
 .../hcaptcha/sdk/HCaptchaJSInterfaceTest.java |  42 +-
 .../com/hcaptcha/sdk/HCaptchaSizeTest.java    |   4 +-
 .../java/com/hcaptcha/sdk/HCaptchaTest.java   |  26 +-
 .../com/hcaptcha/sdk/HCaptchaThemeTest.java   |   4 +-
 .../sdk/HCaptchaWebViewHelperTest.java        |  10 +-
 41 files changed, 971 insertions(+), 221 deletions(-)
 create mode 100644 example-app/src/main/java/com/hcaptcha/example/App.java
 create mode 100644 gradle/config/checkstyle.xml
 create mode 100644 gradle/config/cve.xml
 create mode 100644 gradle/config/findbugs-exclude.xml
 create mode 100644 gradle/config/pmd.xml
 create mode 100644 lombok.config

diff --git a/CHANGES.md b/CHANGES.md
index a36ac88d..d752704d 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,5 +1,9 @@
 # Changelog
 
+# 3.1.0
+
+- Add `pmd`, `checkstyle`, `spotbugs` tools to build system ([#40](https://github.com/hCaptcha/hcaptcha-android-sdk/issues/40))
+
 # 3.0.0
 
 - Add new boolean config option `HCaptchaConfig.hideDialog`.
diff --git a/build.gradle b/build.gradle
index ce622ead..2135ac58 100644
--- a/build.gradle
+++ b/build.gradle
@@ -3,10 +3,10 @@ buildscript {
     repositories {
         google()
         mavenCentral()
+        maven { url 'https://jitpack.io' }
     }
     dependencies {
         classpath 'com.android.tools.build:gradle:4.1.3'
-
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
     }
diff --git a/example-app/src/main/AndroidManifest.xml b/example-app/src/main/AndroidManifest.xml
index 92f8d8f8..9cdc15ca 100644
--- a/example-app/src/main/AndroidManifest.xml
+++ b/example-app/src/main/AndroidManifest.xml
@@ -5,6 +5,7 @@
     <uses-permission android:name="android.permission.INTERNET" />
 
     <application
+        android:name=".App"
         android:allowBackup="true"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
diff --git a/example-app/src/main/java/com/hcaptcha/example/App.java b/example-app/src/main/java/com/hcaptcha/example/App.java
new file mode 100644
index 00000000..d783b16a
--- /dev/null
+++ b/example-app/src/main/java/com/hcaptcha/example/App.java
@@ -0,0 +1,26 @@
+package com.hcaptcha.example;
+
+import android.app.Application;
+import android.os.StrictMode;
+
+public class App extends Application {
+    @Override
+    public void onCreate() {
+        super.onCreate();
+
+        if (BuildConfig.DEBUG) {
+            StrictMode.setThreadPolicy(
+                    new StrictMode.ThreadPolicy.Builder()
+                            .detectAll()
+                            .penaltyLog()
+                            .build()
+            );
+            StrictMode.setVmPolicy(
+                    new StrictMode.VmPolicy.Builder()
+                            .detectAll()
+                            .penaltyLog()
+                            .build()
+            );
+        }
+    }
+}
diff --git a/gradle/config/checkstyle.xml b/gradle/config/checkstyle.xml
new file mode 100644
index 00000000..fee80809
--- /dev/null
+++ b/gradle/config/checkstyle.xml
@@ -0,0 +1,385 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE module PUBLIC "-//Puppy Crawl//DTD Check Configuration 1.3//EN" "http://www.puppycrawl.org/dtds/configuration_1_3.dtd">
+
+<!--
+Checkstyle-Configuration: Android Style
+Description: https://source.android.com/source/code-style.html
+-->
+<module name="Checker">
+  <property name="fileExtensions" value="java, properties, xml"/>
+
+  <!-- Require UTF-8 encoding for all files -->
+  <property name="charset" value="UTF-8"/>
+
+  <!-- Default severity is error -->
+  <property name="severity" value="warning"/>
+
+    <!-- 100 char per line max, unless unavoidable -->
+  <module name="LineLength">
+        <property name="max" value="120"/>
+        <property name="ignorePattern"
+                  value="^package.*|^import.*|a href|href|http://|https://|ftp://"/>
+  </module>
+
+  <module name="TreeWalker">
+
+    <!--#################################################################-->
+    <!--################ NAMING CHECKS ##################################-->
+    <!--#################################################################-->
+
+    <!-- Require package names to be all lower-case -->
+    <module name="PackageName">
+        <property name="format" value="^[a-z]+(\.[a-z][a-z0-9]*)*$"/>
+        <message key="name.invalidPattern"
+                 value="Package name ''{0}'' must be lower-case."/>
+    </module>
+
+    <!-- Require standard type names -->
+    <module name="TypeName">
+        <message key="name.invalidPattern"
+         value="Type name ''{0}'' must begin with a capital letter."/>
+    </module>
+
+    <!--
+    Type parameters must either be a single upper-case character, or must begin
+    with an upper-case character and end with "T" (e.g. DataT).
+    -->
+    <module name="ClassTypeParameterName">
+      <property name="format" value="(^[A-Z][0-9]?)$|([T][A-Z][a-zA-Z0-9]+$)"/>
+      <message key="name.invalidPattern"
+               value="Class type parameter ''{0}'' must either be a single upper-case character, or begin with an upper-case character and begin with 'T'."/>
+    </module>
+
+    <!--
+    Require method names to be at least two characters long, and start with a
+    lower case letter.
+    -->
+    <module name="MethodName">
+      <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9_]*$"/>
+      <message key="name.invalidPattern"
+               value="Method name ''{0}'' must be at least two characters long."/>
+    </module>
+
+    <!-- Require parameter names to be at least two characters long -->
+    <module name="ParameterName">
+        <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9]*$"/>
+        <message key="name.invalidPattern"
+                 value="Parameter name ''{0}'' must be at least two characters long."/>
+    </module>
+
+    <!--
+    Require local variables to be at least two characters long,
+    unless they are counters on a for loop.
+    -->
+    <module name="LocalVariableName">
+        <property name="tokens" value="VARIABLE_DEF"/>
+        <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9]*$"/>
+        <property name="allowOneCharVarInForLoop" value="true"/>
+        <message key="name.invalidPattern"
+                 value="Local variable name ''{0}'' must be at least two characters long."/>
+    </module>
+
+    <!-- Require that constants be capitalized. -->
+    <module name="ConstantName"/>
+
+    <module name="LocalFinalVariableName"/>
+
+    <!--
+    Require that static, non-public, non-final variable names be prefixed
+    with "s".
+    -->
+    <module name="StaticVariableName">
+      <property name="format" value="^s[A-Z][a-zA-Z0-9]*$"/>
+      <message key="name.invalidPattern"
+               value="Static variable name ''{0}'' must be prefixed with s and be at least two characters long."/>
+    </module>
+
+    <!-- Capitalized abbreviations are forbidden (e.g. URL, XML, HTTP) -->
+    <module name="AbbreviationAsWordInName">
+        <property name="ignoreFinal" value="false"/>
+        <property name="allowedAbbreviationLength" value="2"/>
+    </module>
+
+    <!-- Forbid unnecessary escaping. -->
+    <module name="IllegalTokenText">
+      <property name="tokens" value="STRING_LITERAL, CHAR_LITERAL"/>
+      <property name="format" value="\\u00(08|09|0(a|A)|0(c|C)|0(d|D)|22|27|5(C|c))|\\(0(10|11|12|14|15|42|47)|134)"/>
+      <property name="message" value="Avoid using corresponding octal or Unicode escape."/>
+    </module>
+
+    <!-- Forbid unnecessary unicode escapes -->
+    <module name="AvoidEscapedUnicodeCharacters">
+        <property name="allowEscapesForControlCharacters" value="true"/>
+        <property name="allowByTailComment" value="true"/>
+        <property name="allowNonPrintableEscapes" value="true"/>
+    </module>
+
+    <!-- Require array notation on type (e.g. int[] x, not int x[]) -->
+    <module name="ArrayTypeStyle"/>
+
+    <!--###################################################-->
+    <!--################ IMPORTS ##########################-->
+    <!--###################################################-->
+
+    <!-- Star imports are forbidden. -->
+    <module name="AvoidStarImport"/>
+
+    <!-- Android imports come first -->
+    <module name="CustomImportOrder">
+        <property name="specialImportsRegExp" value="android"/>
+        <property name="sortImportsInGroupAlphabetically" value="true"/>
+        <property name="customImportOrderRules" value="STATIC###SPECIAL_IMPORTS###THIRD_PARTY_PACKAGE###STANDARD_JAVA_PACKAGE"/>
+    </module>
+
+    <!-- Forbid imports from sun.* -->
+    <module name="IllegalImport"/>
+
+    <!-- Forbid redudant imports (e.g. import java.lang.String;) -->
+    <module name="RedundantImport"/>
+
+    <!-- Forbid unused imports -->
+    <module name="UnusedImports"/>
+
+    <!-- Forbid redundant modifiers -->
+    <module name="RedundantModifier"/>
+
+    <!--##############################################################-->
+    <!--################ STRUCTURAL / WRAPPING CHECKS ################-->
+    <!--##############################################################-->
+
+    <!-- Require One top-level class per file -->
+    <module name="OneTopLevelClass"/>
+
+    <!-- Line-wrapping in import statements is forbidden. -->
+    <module name="NoLineWrap"/>
+
+    <!-- Empty catch blocks are forbidden. -->
+    <module name="EmptyCatchBlock">
+      <property name="exceptionVariableName" value="expected|ignore"/>
+    </module>
+
+    <!-- Require braces for all code blocks -->
+    <module name="NeedBraces"/>
+
+    <!-- Require One statement per line (e.g. no "a = b; c = d;") -->
+    <module name="OneStatementPerLine"/>
+
+    <!-- Multiple variable declarations on one line is forbidden. -->
+    <module name="MultipleVariableDeclarations"/>
+
+    <!-- Require switch statements to have default clause -->
+    <module name="MissingSwitchDefault"/>
+
+    <!--
+    Case fall-through in switch statements is forbidden, except where an
+    explicit "// fall-through" comment exists.
+    -->
+    <module name="FallThrough">
+      <property name="reliefPattern" value="fall-through"/>
+    </module>
+
+    <!-- Require empty lines between definitions -->
+    <module name="EmptyLineSeparator">
+        <property name="allowNoEmptyLineBetweenFields" value="true"/>
+    </module>
+
+    <!-- Wrap only permitted before dot, e.g.
+    fluentInterface.doX()
+        .doY()
+        .doZ();
+    -->
+    <module name="SeparatorWrap">
+      <property name="tokens" value="DOT"/>
+      <property name="option" value="nl"/>
+    </module>
+
+    <!-- Wrap only permitted after comma, e.g.
+    doThings(withA,
+        withB,
+        withC);
+    -->
+    <module name="SeparatorWrap">
+        <property name="tokens" value="COMMA"/>
+        <property name="option" value="EOL"/>
+    </module>
+
+    <!-- require line breaks before common binary operators -->
+    <module name="OperatorWrap">
+        <property name="option" value="NL"/>
+        <property name="tokens" value="BAND, BOR, BSR, BXOR, DIV, EQUAL, GE, GT, LAND, LE, LITERAL_INSTANCEOF, LOR, LT, MINUS, MOD, NOT_EQUAL, PLUS, QUESTION, SL, SR, STAR "/>
+    </module>
+
+    <!--
+    Require that annotations on type, method and constructor definitions be on
+    a separate line.
+    -->
+    <module name="AnnotationLocation">
+      <property name="tokens" value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF"/>
+    </module>
+
+    <!--
+    Variable declarations may have annotations on the same line.
+    -->
+    <module name="AnnotationLocation">
+        <property name="tokens" value="VARIABLE_DEF"/>
+        <property name="allowSamelineMultipleAnnotations" value="true"/>
+    </module>
+
+    <!-- Forbid empty statements -->
+    <module name="EmptyStatement"/>
+
+    <!--#################################################################-->
+    <!--################ WHITESPACE / LINE LENGTH CHECKS ################-->
+    <!--#################################################################-->
+
+    <!-- Forbid whitespace after prefix unary operators and accessors -->
+    <module name="NoWhitespaceAfter">
+      <property name="tokens" value="BNOT,DEC,DOT,INC,LNOT,UNARY_MINUS,UNARY_PLUS"/>
+    </module>
+
+    <!--
+    Forbid whitespace before comma, semi-colon, and postfix unary operators
+    -->
+    <module name="NoWhitespaceBefore"/>
+
+    <!-- Require whitespace around common tokens (=, if, etc.) -->
+    <module name="WhitespaceAround">
+      <property name="allowEmptyConstructors" value="true"/>
+      <property name="allowEmptyMethods" value="true"/>
+      <property name="allowEmptyTypes" value="true"/>
+      <property name="allowEmptyLoops" value="true"/>
+      <message key="ws.notFollowed"
+       value="WhitespaceAround: ''{0}'' is not followed by whitespace. Empty blocks may only be represented as '{}' when not part of a multi-block statement (4.1.3)"/>
+       <message key="ws.notPreceded"
+       value="WhitespaceAround: ''{0}'' is not preceded with whitespace."/>
+    </module>
+
+    <!-- Require standard whitespace around type parameters -->
+    <module name="GenericWhitespace">
+      <message key="ws.followed"
+               value="GenericWhitespace ''{0}'' is followed by whitespace."/>
+       <message key="ws.preceded"
+                value="GenericWhitespace ''{0}'' is preceded with whitespace."/>
+       <message key="ws.illegalFollow"
+                value="GenericWhitespace ''{0}'' should followed by whitespace."/>
+       <message key="ws.notPreceded"
+                value="GenericWhitespace ''{0}'' is not preceded with whitespace."/>
+    </module>
+
+    <!-- Require Android standard indentation. -->
+    <module name="Indentation">
+        <property name="basicOffset" value="4"/>
+        <property name="braceAdjustment" value="0"/>
+        <property name="caseIndent" value="4"/>
+        <property name="throwsIndent" value="8"/>
+        <property name="lineWrappingIndentation" value="8"/>
+        <property name="arrayInitIndent" value="4"/>
+    </module>
+
+    <!--
+    Require that comments be placed at the same level of indentation as
+    surrounding code.
+    -->
+    <module name="CommentsIndentation"/>
+
+    <!--#################################################################-->
+    <!--################ MISC. LANGUAGE CHECKS ##########################-->
+    <!--#################################################################-->
+
+    <!-- File name must correspond to contained class -->
+    <module name="OuterTypeFilename"/>
+
+    <!--
+    Long constants must be suffixed with L:
+    "The suffix L is preferred, because the letter l (ell) is often hard to
+    distinguish from the digit 1 (one)."
+    http://docs.oracle.com/javase/specs/jls/se8/html/jls-3.html#jls-3.10.1
+    -->
+    <module name="UpperEll"/>
+
+    <!--
+    Require modifier order consistent with recommends in JLS:
+    http://docs.oracle.com/javase/specs/jls/se8/html/jls-8.html
+    -->
+    <module name="ModifierOrder"/>
+
+    <!-- Finalizers are forbidden. -->
+    <module name="NoFinalizer"/>
+
+    <!-- overloaded methods must be grouped together -->
+    <module name="OverloadMethodsDeclarationOrder"/>
+
+    <!-- Require variables to be declared close to where they are used -->
+    <module name="VariableDeclarationUsageDistance"/>
+
+    <!-- Require that equals() and hashCode() are overridden together -->
+    <module name="EqualsHashCode"/>
+
+    <!-- Forbid shadowing fields or variables -->
+    <module name="HiddenField">
+      <!-- exception: constructor parameters -->
+      <property name="ignoreConstructorParameter" value="true"/>
+      <!-- exception: setter method parameters -->
+      <property name="ignoreSetter" value="true"/>
+    </module>
+
+    <!--
+    Forbid assignments in expressions, with the exception of loop conditions
+    -->
+    <module name="InnerAssignment"/>
+
+    <!-- Require @Override on overridden methods -->
+    <module name="MissingOverride"/>
+
+    <!-- Forbid arbitrarily nested blocks -->
+    <module name="AvoidNestedBlocks"/>
+
+    <!-- Forbid the use of arbitrary numeric literals -->
+    <module name="MagicNumber">
+        <property name="ignoreFieldDeclaration" value="true"/>
+        <property name="ignoreNumbers" value="0, 1, 2, 512, 200"/>
+        <property name="ignoreAnnotation" value="true"/>
+    </module>
+
+    <!-- Require boolean expressions to be simplifed -->
+    <module name="SimplifyBooleanExpression"/>
+
+    <!-- Require boolean returns to be simplified -->
+    <module name="SimplifyBooleanReturn"/>
+
+    <!-- Forbid interfaces with no methods -->
+    <module name="InterfaceIsType"/>
+
+    <!-- Enable @SuppressWarning annotation -->
+    <module name="SuppressWarningsHolder"/>
+
+    <module name="FinalLocalVariableCheck"/>
+  </module>
+
+  <!--################################################-->
+  <!--################ Non-AST checks ################-->
+  <!--################################################-->
+
+  <!-- Ensure the copyright header appears in every java source file -->
+  <!--module name="RegexpHeader">
+    <property name="headerFile" value="${checkstyle.java.header}"/>
+    <property name="fileExtensions" value="java"/>
+  </module-->
+
+  <!-- Report every line containing a tab character" -->
+  <module name="FileTabCharacter">
+    <property name="eachLine" value="true"/>
+  </module>
+
+  <!-- Forbid trailing whitespace -->
+  <module name="RegexpSingleline">
+    <property name="format" value="\s+$"/>
+    <property name="message" value="Line has trailing whitespace."/>
+  </module>
+
+  <!-- Require a new line at the end of all files -->
+  <module name="NewlineAtEndOfFile"/>
+
+  <!-- Enable @SuppressWarning annotation -->
+  <module name="SuppressWarningsFilter"/>
+</module>
diff --git a/gradle/config/cve.xml b/gradle/config/cve.xml
new file mode 100644
index 00000000..545593c0
--- /dev/null
+++ b/gradle/config/cve.xml
@@ -0,0 +1,113 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<suppressions xmlns="https://jeremylong.github.io/DependencyCheck/dependency-suppression.1.3.xsd">
+    <suppress>
+        <notes><![CDATA[
+    file name: openssl/opensslv.h
+    Affects openssl versions prior to 0.9.2b
+    We currently use openssl 1.1.1d
+    see: https://vuldb.com/?id.14576
+    ]]></notes>
+        <packageUrl regex="true">^pkg:generic/openssl@.*$</packageUrl>
+        <cve>CVE-1999-0428</cve>
+    </suppress>
+    <suppress>
+        <notes><![CDATA[
+    file name: openssl/opensslv.h
+    Affects openssl versions prior to 0.9.8k
+    We currently use openssl 1.1.1d
+    ]]></notes>
+        <packageUrl regex="true">^pkg:generic/openssl@.*$</packageUrl>
+        <cve>CVE-2009-0590</cve>
+    </suppress>
+    <suppress>
+        <notes><![CDATA[
+    file name: openssl/opensslv.h
+    This vulnerability deals with an interaction between openssl and Apache. We aren't using Apache 2.4.37
+    ]]></notes>
+        <packageUrl regex="true">^pkg:generic/openssl@.*$</packageUrl>
+        <cve>CVE-2019-0190</cve>
+    </suppress>
+    <suppress>
+        <notes><![CDATA[
+   file name: openssl/opensslv.h
+   This vulnerability was fixed in OpenSSL 1.1.1e-dev, which is currently not available as a stable release yet.
+   We currently use openssl 1.1.1d.
+   ]]></notes>
+        <packageUrl regex="true">^pkg:generic/openssl@.*$</packageUrl>
+        <cve>CVE-2019-1551</cve>
+    </suppress>
+    <suppress>
+        <notes><![CDATA[
+    file name: gradle-wrapper.jar
+    Affects gradle versions up to 5.3.1
+    We currently use gradle 5.6.4
+    ]]></notes>
+        <sha1>636cf935a0fd1451657a4112974b3500cce3ab84</sha1>
+        <cve>CVE-2019-11065</cve>
+    </suppress>
+    <suppress>
+        <notes><![CDATA[
+    file name: gradle-wrapper.jar
+    Affects gradle versions prior to 5.6
+    We currently use gradle 5.6.4
+    ]]></notes>
+        <sha1>636cf935a0fd1451657a4112974b3500cce3ab84</sha1>
+        <cve>CVE-2019-15052</cve>
+    </suppress>
+    <suppress>
+        <notes><![CDATA[
+    file name: bcprov-jdk15on-1.56.jar
+    Suppress build tools vulnerabilities because we are bound by build tools version 3.4.1
+    ]]></notes>
+        <packageUrl regex="true">^pkg:maven/org\.bouncycastle/bcprov\-jdk15on@.*$</packageUrl>
+        <cve>CVE-2017-13098</cve>
+    </suppress>
+    <suppress>
+        <notes><![CDATA[
+    file name: bcprov-jdk15on-1.56.jar
+    Suppress build tools vulnerabilities because we are bound by build tools version 3.4.1
+    ]]></notes>
+        <packageUrl regex="true">^pkg:maven/org\.bouncycastle/bcprov\-jdk15on@.*$</packageUrl>
+        <cve>CVE-2018-1000180</cve>
+    </suppress>
+    <suppress>
+        <notes><![CDATA[
+    file name: bcprov-jdk15on-1.56.jar
+    Suppress build tools vulnerabilities because we are bound by build tools version 3.4.1
+    ]]></notes>
+        <packageUrl regex="true">^pkg:maven/org\.bouncycastle/bcprov\-jdk15on@.*$</packageUrl>
+        <cve>CVE-2018-1000613</cve>
+    </suppress>
+    <suppress>
+        <notes><![CDATA[
+    file name: commons-compress-1.12.jar
+    Suppress build tools vulnerabilities because we are bound by build tools version 3.4.1
+    ]]></notes>
+        <packageUrl regex="true">^pkg:maven/org\.apache\.commons/commons\-compress@.*$</packageUrl>
+        <cve>CVE-2018-11771</cve>
+    </suppress>
+    <suppress>
+        <notes><![CDATA[
+    file name: commons-compress-1.12.jar
+    Suppress build tools vulnerabilities because we are bound by build tools version 3.4.1
+    ]]></notes>
+        <packageUrl regex="true">^pkg:maven/org\.apache\.commons/commons\-compress@.*$</packageUrl>
+        <cve>CVE-2018-1324</cve>
+    </suppress>
+    <suppress>
+        <notes><![CDATA[
+    file name: intellij-core-26.4.1.jar (shaded: com.google.protobuf:protobuf-java:2.6.1)
+    Suppress build tools vulnerabilities because we are bound by build tools version 3.4.1
+    ]]></notes>
+        <packageUrl regex="true">^pkg:maven/com\.google\.protobuf/protobuf\-java@.*$</packageUrl>
+        <vulnerabilityName>CVE-2015-5237</vulnerabilityName>
+    </suppress>
+    <suppress>
+        <notes><![CDATA[
+    file name: builder-3.4.1.jar: desugar_deploy.jar (shaded: com.google.guava:guava:21.0)
+    Suppress build tools vulnerabilities because we are bound by build tools version 3.4.1
+    ]]></notes>
+        <packageUrl regex="true">^pkg:maven/com\.google\.guava/guava@.*$</packageUrl>
+        <cve>CVE-2018-10237</cve>
+    </suppress>
+</suppressions>
diff --git a/gradle/config/findbugs-exclude.xml b/gradle/config/findbugs-exclude.xml
new file mode 100644
index 00000000..635034dd
--- /dev/null
+++ b/gradle/config/findbugs-exclude.xml
@@ -0,0 +1,30 @@
+<FindBugsFilter>
+    <!-- Do not check auto-generated resources classes -->
+    <Match>
+        <Class name="~.*R\$.*"/>
+    </Match>
+ 
+    <!-- Do not check auto-generated manifest classes -->
+    <Match>
+        <Class name="~.*Manifest\$.*"/>
+    </Match>
+ 
+    <!-- Do not check auto-generated classes (Dagger puts $ into class names) -->
+    <Match>
+        <Class name="~.*Dagger*.*"/>
+    </Match>
+
+    <!-- Do not check auto-generated classes -->
+    <Match>
+        <Class name=".*" annotation="@lombok.Generated"/>
+    </Match>
+     
+    <!-- http://findbugs.sourceforge.net/bugDescriptions.html#ST_WRITE_TO_STATIC_FROM_INSTANCE_METHOD-->
+    <Match>
+        <Bug pattern="ST_WRITE_TO_STATIC_FROM_INSTANCE_METHOD"/>
+    </Match>
+
+    <Match>
+        <Bug pattern="EI_EXPOSE_REP2"/>
+    </Match>
+</FindBugsFilter>
diff --git a/gradle/config/pmd.xml b/gradle/config/pmd.xml
new file mode 100644
index 00000000..6cf6c3c7
--- /dev/null
+++ b/gradle/config/pmd.xml
@@ -0,0 +1,18 @@
+<?xml version="1.0"?>
+<ruleset name="hcaptcha-pmd"
+    xmlns="http://pmd.sourceforge.net/ruleset/2.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://pmd.sourceforge.net/ruleset/2.0.0 https://pmd.sourceforge.io/ruleset_2_0_0.xsd">
+    <description>HCaptcha Android SDK RuleSet</description>
+	<exclude-pattern>.*/R.java</exclude-pattern>
+    <exclude-pattern>.*/gen/.*</exclude-pattern>
+    <rule ref="rulesets/java/basic.xml" />
+    <rule ref="rulesets/java/braces.xml" />
+    <rule ref="rulesets/java/strings.xml" />
+    <rule ref="rulesets/java/design.xml" >
+        <exclude name="AbstractClassWithoutAbstractMethod" />
+        <exclude name="AvoidDeeplyNestedIfStmts" />
+        <exclude name="EmptyMethodInAbstractClassShouldBeAbstract" />
+    </rule>
+    <rule ref="rulesets/java/unusedcode.xml" />
+</ruleset>
diff --git a/lombok.config b/lombok.config
new file mode 100644
index 00000000..b3a159f8
--- /dev/null
+++ b/lombok.config
@@ -0,0 +1,5 @@
+config.stopBubbling = true
+lombok.addLombokGeneratedAnnotation = true
+lombok.extern.findbugs.addSuppressFBWarnings = true
+lombok.addNullAnnotations = findbugs
+lombok.addSuppressWarnings = false
\ No newline at end of file
diff --git a/sdk/build.gradle b/sdk/build.gradle
index 01bd483b..1cf2c1f9 100644
--- a/sdk/build.gradle
+++ b/sdk/build.gradle
@@ -1,3 +1,10 @@
+plugins {
+    id "pmd"
+    id "checkstyle"
+    id "com.github.spotbugs" version "4.8.0"
+    id "org.owasp.dependencycheck" version "7.1.1"
+}
+
 apply plugin: 'com.android.library'
 apply plugin: 'maven-publish'
 
@@ -12,11 +19,11 @@ android {
         // See https://developer.android.com/studio/publish/versioning
         // versionCode must be integer and be incremented by one for every new update
         // android system uses this to prevent downgrades
-        versionCode 13
+        versionCode 14
 
         // version number visible to the user
         // should follow semantic versioning (See https://semver.org)
-        versionName "3.0.0"
+        versionName "3.1.0"
 
         buildConfigField 'String', 'VERSION_NAME', "\"${defaultConfig.versionName}_${defaultConfig.versionCode}\""
 
@@ -58,6 +65,8 @@ dependencies {
     androidTestImplementation 'org.hamcrest:hamcrest-library:1.3'
 
     debugImplementation 'androidx.fragment:fragment-testing:1.4.1'
+
+    compileOnly 'com.google.code.findbugs:annotations:3.0.1'
 }
 
 task androidJavadocs(type: Javadoc) {
@@ -150,3 +159,52 @@ android.libraryVariants.all { variant ->
         }
     })
 }
+
+task checkstyle(type: Checkstyle) {
+    description 'Check code standard'
+    group 'verification'
+    configFile file("${rootDir}/gradle/config/checkstyle.xml")
+    source 'src'
+    include '**/*.java'
+    exclude '**/gen/**'
+    classpath = files()
+    ignoreFailures = false
+    maxWarnings = 0
+}
+
+task pmd(type: Pmd) {
+    ruleSetFiles = files("${project.rootDir}/gradle/config/pmd.xml")
+    ignoreFailures = false
+    ruleSets = []
+    source 'src'
+    include '**/*.java'
+    exclude '**/gen/**'
+    reports {
+        xml.enabled = false
+        html.enabled = true
+        html.destination = file("$project.buildDir/outputs/pmd/pmd.html")
+    }
+}
+
+spotbugs {
+    ignoreFailures = false
+    showStackTraces = true
+    showProgress = false
+    reportLevel = 'high'
+    excludeFilter = file("${project.rootDir}/gradle/config/findbugs-exclude.xml")
+    onlyAnalyze = ['com.hcaptcha.sdk.*']
+    projectName = name
+    release = version
+}
+
+// enable html report
+gradle.taskGraph.beforeTask { task ->
+    if (task.name.toLowerCase().contains('spotbugs')) {
+        task.reports {
+            html.enabled = true
+            xml.enabled = true
+        }
+    }
+}
+
+check.dependsOn('checkstyle', 'pmd')
diff --git a/sdk/src/androidTest/assets/hcaptcha-form.html b/sdk/src/androidTest/assets/hcaptcha-form.html
index 7a366817..09123100 100644
--- a/sdk/src/androidTest/assets/hcaptcha-form.html
+++ b/sdk/src/androidTest/assets/hcaptcha-form.html
@@ -11,7 +11,8 @@
     <button id="on-pass" onclick="onPass()">Pass</button>
 
     <script type="text/javascript">
-        var DI = window.JSDI.getDebugInfo();
+        console.assert(window.JSDI.getDebugInfo() instanceof Array);
+        console.assert(typeof window.JSDI.getSysDebug() === 'object');
         var BridgeObject = window.JSInterface;
         var bridgeConfig = JSON.parse(BridgeObject.getConfig());
 
diff --git a/sdk/src/androidTest/java/com/hcaptcha/sdk/AssertUtil.java b/sdk/src/androidTest/java/com/hcaptcha/sdk/AssertUtil.java
index e8d33103..44fce5c5 100644
--- a/sdk/src/androidTest/java/com/hcaptcha/sdk/AssertUtil.java
+++ b/sdk/src/androidTest/java/com/hcaptcha/sdk/AssertUtil.java
@@ -1,27 +1,38 @@
 package com.hcaptcha.sdk;
 
+import static androidx.test.espresso.matcher.ViewMatchers.isAssignableFrom;
+import static androidx.test.espresso.matcher.ViewMatchers.isDisplayed;
+import static org.hamcrest.CoreMatchers.any;
+
 import android.view.View;
 import android.webkit.ValueCallback;
 import android.webkit.WebView;
-
 import androidx.test.espresso.PerformException;
 import androidx.test.espresso.UiController;
 import androidx.test.espresso.ViewAction;
-import androidx.test.espresso.ViewAssertion;
 import androidx.test.espresso.util.HumanReadables;
 import androidx.test.espresso.util.TreeIterables;
+
 import org.hamcrest.Matcher;
 
 import java.util.Locale;
 import java.util.concurrent.TimeoutException;
 import java.util.concurrent.atomic.AtomicBoolean;
 
-import static androidx.test.espresso.assertion.ViewAssertions.doesNotExist;
-import static androidx.test.espresso.matcher.ViewMatchers.*;
-import static org.hamcrest.CoreMatchers.any;
-import static org.hamcrest.CoreMatchers.not;
+/**
+ * Helper class with different ViewActions
+ */
+public final class AssertUtil {
+
+    private static final long MAIN_LOOP_DELAY_MS = 50;
+    private static final long WAIT_TO_BE_DISPLAYED_MS = 1000;
 
-public class AssertUtil {
+    private AssertUtil() {
+    }
+
+    public static ViewAction waitToBeDisplayed() {
+        return waitToBeDisplayed(WAIT_TO_BE_DISPLAYED_MS);
+    }
 
     public static ViewAction waitToBeDisplayed(final long millis) {
         return new ViewAction() {
@@ -46,7 +57,7 @@ public void perform(final UiController uiController, final View view) {
                             return;
                         }
                     }
-                    uiController.loopMainThreadForAtLeast(50);
+                    uiController.loopMainThreadForAtLeast(MAIN_LOOP_DELAY_MS);
                 }
                 while (System.currentTimeMillis() < endTime);
                 throw new PerformException.Builder()
@@ -72,13 +83,13 @@ public String getDescription() {
 
             @Override
             public void perform(final UiController uiController, final View view) {
-                long endTime = System.currentTimeMillis() + millis;
+                final long endTime = System.currentTimeMillis() + millis;
 
                 do {
                     if (view.getVisibility() == View.GONE || view.getVisibility() == View.INVISIBLE) {
                         return;
                     }
-                    uiController.loopMainThreadForAtLeast(50);
+                    uiController.loopMainThreadForAtLeast(MAIN_LOOP_DELAY_MS);
                 } while (System.currentTimeMillis() < endTime);
 
                 throw new PerformException.Builder()
@@ -91,15 +102,13 @@ public void perform(final UiController uiController, final View view) {
     }
 
     // https://stackoverflow.com/a/38385064/902217
-    public static abstract class EvaluateJsAction implements ViewAction, ValueCallback<String> {}
+    public abstract static class EvaluateJsAction implements ViewAction, ValueCallback<String> {}  // NOPMD
 
     public static ViewAction evaluateJavascript(final String jsCode) {
         return new EvaluateJsAction() {
-
             private static final long TIME_OUT = 5000;
             private final AtomicBoolean mEvaluateFinished = new AtomicBoolean(false);
 
-
             @Override
             public Matcher<View> getConstraints() {
                 return isAssignableFrom(WebView.class);
@@ -127,7 +136,7 @@ public void perform(UiController uiController, View view) {
                                         "Evaluating java script did not finish after %d ms of waiting.", TIME_OUT)))
                                 .build();
                     }
-                    uiController.loopMainThreadForAtLeast(50);
+                    uiController.loopMainThreadForAtLeast(MAIN_LOOP_DELAY_MS);
                 }
             }
 
diff --git a/sdk/src/androidTest/java/com/hcaptcha/sdk/ExampleInstrumentedTest.java b/sdk/src/androidTest/java/com/hcaptcha/sdk/ExampleInstrumentedTest.java
index 153eeacd..7fc12d44 100644
--- a/sdk/src/androidTest/java/com/hcaptcha/sdk/ExampleInstrumentedTest.java
+++ b/sdk/src/androidTest/java/com/hcaptcha/sdk/ExampleInstrumentedTest.java
@@ -1,13 +1,14 @@
 package com.hcaptcha.sdk;
 
+import static org.junit.Assert.assertEquals;
+
 import android.content.Context;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 import androidx.test.platform.app.InstrumentationRegistry;
+
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
-import static org.junit.Assert.assertEquals;
-
 /**
  * Instrumented test, which will execute on an Android device.
  *
@@ -18,7 +19,7 @@ public class ExampleInstrumentedTest {
     @Test
     public void useAppContext() {
         // Context of the app under test.
-        Context appContext = InstrumentationRegistry.getInstrumentation().getTargetContext();
+        final Context appContext = InstrumentationRegistry.getInstrumentation().getTargetContext();
         assertEquals("com.hcaptcha.sdk.test", appContext.getPackageName());
     }
 }
diff --git a/sdk/src/androidTest/java/com/hcaptcha/sdk/HCaptchaDialogFragmentTest.java b/sdk/src/androidTest/java/com/hcaptcha/sdk/HCaptchaDialogFragmentTest.java
index a62bec6c..d8bdcbbd 100644
--- a/sdk/src/androidTest/java/com/hcaptcha/sdk/HCaptchaDialogFragmentTest.java
+++ b/sdk/src/androidTest/java/com/hcaptcha/sdk/HCaptchaDialogFragmentTest.java
@@ -1,18 +1,9 @@
 package com.hcaptcha.sdk;
 
-import android.os.Bundle;
-
-import androidx.fragment.app.testing.FragmentScenario;
-import androidx.test.espresso.web.webdriver.DriverAtoms;
-import androidx.test.espresso.web.webdriver.Locator;
-import androidx.test.ext.junit.runners.AndroidJUnit4;
-
-import org.junit.Test;
-import org.junit.runner.RunWith;
-
 import static androidx.test.espresso.Espresso.onView;
 import static androidx.test.espresso.assertion.ViewAssertions.matches;
-import static androidx.test.espresso.matcher.ViewMatchers.*;
+import static androidx.test.espresso.matcher.ViewMatchers.isDisplayed;
+import static androidx.test.espresso.matcher.ViewMatchers.withId;
 import static androidx.test.espresso.web.sugar.Web.onWebView;
 import static androidx.test.espresso.web.webdriver.DriverAtoms.clearElement;
 import static androidx.test.espresso.web.webdriver.DriverAtoms.findElement;
@@ -25,12 +16,23 @@
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 
+import android.os.Bundle;
+import androidx.fragment.app.testing.FragmentScenario;
+import androidx.test.espresso.web.webdriver.DriverAtoms;
+import androidx.test.espresso.web.webdriver.Locator;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
 
 
 @RunWith(AndroidJUnit4.class)
 public class HCaptchaDialogFragmentTest {
+    private static final long AWAIT_CALLBACK_MS = 1000;
+
     public FragmentScenario<HCaptchaDialogFragment> launchCaptchaFragment() {
         return launchCaptchaFragment(true);
     }
@@ -43,7 +45,8 @@ public FragmentScenario<HCaptchaDialogFragment> launchCaptchaFragment(HCaptchaSt
         return launchCaptchaFragment(true, listener);
     }
 
-    public FragmentScenario<HCaptchaDialogFragment> launchCaptchaFragment(boolean showLoader, HCaptchaStateListener listener) {
+    public FragmentScenario<HCaptchaDialogFragment> launchCaptchaFragment(boolean showLoader,
+                                                                          HCaptchaStateListener listener) {
         final HCaptchaConfig hCaptchaConfig = HCaptchaConfig.builder()
                 .siteKey("10000000-ffff-ffff-ffff-000000000001")
                 .endpoint("https://js.hcaptcha.com/1/api.js")
@@ -62,30 +65,31 @@ public FragmentScenario<HCaptchaDialogFragment> launchCaptchaFragment(boolean sh
     public void loaderVisible() {
         launchCaptchaFragment();
         onView(withId(R.id.loadingContainer)).check(matches(isDisplayed()));
-        onView(withId(R.id.webView)).perform(waitToBeDisplayed(1000));
-        onView(withId(R.id.loadingContainer)).perform(waitToDisappear(10000));
+        onView(withId(R.id.webView)).perform(waitToBeDisplayed());
+        final long waitToDisappearMs = 10000;
+        onView(withId(R.id.loadingContainer)).perform(waitToDisappear(waitToDisappearMs));
     }
 
     @Test
     public void loaderDisabled() {
         launchCaptchaFragment(false);
         onView(withId(R.id.loadingContainer)).check(matches(not(isDisplayed())));
-        onView(withId(R.id.webView)).perform(waitToBeDisplayed(1000));
+        onView(withId(R.id.webView)).perform(waitToBeDisplayed());
     }
 
     @Test
     public void webViewReturnToken() throws Exception {
-        CountDownLatch latch = new CountDownLatch(1);
+        final CountDownLatch latch = new CountDownLatch(1);
         final HCaptchaStateListener listener = new HCaptchaStateTestAdapter() {
             @Override
-            void onSuccess(HCaptchaTokenResponse hCaptchaTokenResponse) {
-                assertEquals("test-token", hCaptchaTokenResponse.getTokenResult());
+            void onSuccess(HCaptchaTokenResponse response) {
+                assertEquals("test-token", response.getTokenResult());
                 latch.countDown();
             }
         };
 
-        final FragmentScenario<HCaptchaDialogFragment> scenario = launchCaptchaFragment(listener);
-        onView(withId(R.id.webView)).perform(waitToBeDisplayed(1000));
+        launchCaptchaFragment(listener);
+        onView(withId(R.id.webView)).perform(waitToBeDisplayed());
 
         onWebView(withId(R.id.webView)).forceJavascriptEnabled();
 
@@ -96,22 +100,22 @@ void onSuccess(HCaptchaTokenResponse hCaptchaTokenResponse) {
         onWebView().withElement(findElement(Locator.ID, "on-pass"))
                 .perform(webClick());
 
-        assertTrue(latch.await(1000, TimeUnit.MILLISECONDS)); // wait for callback
+        assertTrue(latch.await(AWAIT_CALLBACK_MS, TimeUnit.MILLISECONDS)); // wait for callback
     }
 
     @Test
     public void webViewReturnsError() throws Exception {
-        CountDownLatch latch = new CountDownLatch(1);
+        final CountDownLatch latch = new CountDownLatch(1);
         final HCaptchaStateListener listener = new HCaptchaStateTestAdapter() {
             @Override
-            void onFailure(HCaptchaException hCaptchaException) {
-                assertEquals(HCaptchaError.SESSION_TIMEOUT, hCaptchaException.getHCaptchaError());
+            void onFailure(HCaptchaException exception) {
+                assertEquals(HCaptchaError.SESSION_TIMEOUT, exception.getHCaptchaError());
                 latch.countDown();
             }
         };
 
-        final FragmentScenario<HCaptchaDialogFragment> scenario = launchCaptchaFragment(listener);
-        onView(withId(R.id.webView)).perform(waitToBeDisplayed(1000));
+        launchCaptchaFragment(listener);
+        onView(withId(R.id.webView)).perform(waitToBeDisplayed());
 
         onWebView(withId(R.id.webView)).forceJavascriptEnabled();
 
@@ -123,12 +127,12 @@ void onFailure(HCaptchaException hCaptchaException) {
         onWebView().withElement(findElement(Locator.ID, "on-error"))
                 .perform(webClick());
 
-        assertTrue(latch.await(1000, TimeUnit.MILLISECONDS)); // wait for callback
+        assertTrue(latch.await(AWAIT_CALLBACK_MS, TimeUnit.MILLISECONDS)); // wait for callback
     }
 
     @Test
     public void onOpenCallbackWorks() throws Exception {
-        CountDownLatch latch = new CountDownLatch(1);
+        final CountDownLatch latch = new CountDownLatch(1);
         final HCaptchaStateListener listener = new HCaptchaStateTestAdapter() {
             @Override
             void onOpen() {
@@ -136,8 +140,8 @@ void onOpen() {
             }
         };
 
-        final FragmentScenario<HCaptchaDialogFragment> scenario = launchCaptchaFragment(listener);
-        onView(withId(R.id.webView)).perform(waitToBeDisplayed(1000));
+        launchCaptchaFragment(listener);
+        onView(withId(R.id.webView)).perform(waitToBeDisplayed());
 
         onWebView(withId(R.id.webView)).forceJavascriptEnabled();
 
@@ -148,6 +152,6 @@ void onOpen() {
         onWebView().withElement(findElement(Locator.ID, "on-pass"))
                 .perform(webClick());
 
-        assertTrue(latch.await(1000, TimeUnit.MILLISECONDS)); // wait for callback
+        assertTrue(latch.await(AWAIT_CALLBACK_MS, TimeUnit.MILLISECONDS)); // wait for callback
     }
 }
diff --git a/sdk/src/androidTest/java/com/hcaptcha/sdk/HCaptchaHeadlessWebViewTest.java b/sdk/src/androidTest/java/com/hcaptcha/sdk/HCaptchaHeadlessWebViewTest.java
index 2fb9602a..149dbcd1 100644
--- a/sdk/src/androidTest/java/com/hcaptcha/sdk/HCaptchaHeadlessWebViewTest.java
+++ b/sdk/src/androidTest/java/com/hcaptcha/sdk/HCaptchaHeadlessWebViewTest.java
@@ -10,7 +10,6 @@
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
-
 import androidx.test.core.app.ActivityScenario;
 import androidx.test.ext.junit.rules.ActivityScenarioRule;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
@@ -22,9 +21,10 @@
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
 
-
 @RunWith(AndroidJUnit4.class)
 public class HCaptchaHeadlessWebViewTest {
+    private static final long AWAIT_CALLBACK_MS = 1000;
+
     @Rule
     public ActivityScenarioRule<TestActivity> rule = new ActivityScenarioRule<>(TestActivity.class);
 
@@ -50,7 +50,7 @@ void onSuccess(HCaptchaTokenResponse response) {
             }
 
             @Override
-            void onFailure(HCaptchaException hCaptchaException) {
+            void onFailure(HCaptchaException exception) {
                 fail("Should not be called for this test");
             }
         };
@@ -64,16 +64,13 @@ void onFailure(HCaptchaException hCaptchaException) {
         onWebView().check(webMatches(getCurrentUrl(), containsString("hcaptcha-form.html")));
         onView(withId(R.id.webView)).perform(evaluateJavascript("onPass(\"some-token\")"));
 
-        assertTrue(latch.await(1000, TimeUnit.MILLISECONDS)); // wait for callback
+        assertTrue(latch.await(AWAIT_CALLBACK_MS, TimeUnit.MILLISECONDS)); // wait for callback
     }
 
     @Test
     public void testFailure() throws Exception {
         final CountDownLatch latch = new CountDownLatch(1);
         final HCaptchaStateListener listener = new HCaptchaStateTestAdapter() {
-            @Override
-            void onOpen() {
-            }
 
             @Override
             void onSuccess(HCaptchaTokenResponse response) {
@@ -81,7 +78,7 @@ void onSuccess(HCaptchaTokenResponse response) {
             }
 
             @Override
-            void onFailure(HCaptchaException hCaptchaException) {
+            void onFailure(HCaptchaException exception) {
                 latch.countDown();
             }
         };
@@ -96,6 +93,6 @@ void onFailure(HCaptchaException hCaptchaException) {
         onView(withId(R.id.webView)).perform(evaluateJavascript(
                 "onError(" + HCaptchaError.ERROR.getErrorId() + ")"));
 
-        assertTrue(latch.await(1000, TimeUnit.MILLISECONDS)); // wait for callback
+        assertTrue(latch.await(AWAIT_CALLBACK_MS, TimeUnit.MILLISECONDS)); // wait for callback
     }
 }
diff --git a/sdk/src/androidTest/java/com/hcaptcha/sdk/HCaptchaStateTestAdapter.java b/sdk/src/androidTest/java/com/hcaptcha/sdk/HCaptchaStateTestAdapter.java
index 9e1ae5e6..f969414f 100644
--- a/sdk/src/androidTest/java/com/hcaptcha/sdk/HCaptchaStateTestAdapter.java
+++ b/sdk/src/androidTest/java/com/hcaptcha/sdk/HCaptchaStateTestAdapter.java
@@ -3,13 +3,16 @@
 public class HCaptchaStateTestAdapter extends HCaptchaStateListener {
     @Override
     void onOpen() {
+        // empty default implementation to reduce amount of boilerplate code in tests
     }
 
     @Override
-    void onSuccess(HCaptchaTokenResponse hCaptchaTokenResponse) {
+    void onSuccess(HCaptchaTokenResponse rsponse) {
+        // empty default implementation to reduce amount of boilerplate code in tests
     }
 
     @Override
-    void onFailure(HCaptchaException hCaptchaException) {
+    void onFailure(HCaptchaException exception) {
+        // empty default implementation to reduce amount of boilerplate code in tests
     }
 }
diff --git a/sdk/src/main/assets/hcaptcha-form.html b/sdk/src/main/assets/hcaptcha-form.html
index ffc11950..d912453e 100644
--- a/sdk/src/main/assets/hcaptcha-form.html
+++ b/sdk/src/main/assets/hcaptcha-form.html
@@ -28,7 +28,12 @@
 <div id="hcaptcha-container"></div>
 
 <script type="text/javascript">
-    (window.JSDI ? JSON.parse(window.JSDI.getDebugInfo()) : []).forEach(function (value, i) { window[value] = true; });
+    if (window.JSDI) {
+        JSON.parse(window.JSDI.getDebugInfo()).forEach(function (value) { window[value] = true; });
+        window.sysDebug = JSON.parse(window.JSDI.getSysDebug());
+    }
+</script>
+<script type="text/javascript">
     // Android will inject this bridge object as `JSInterface`
     // Browser is missing it so we mock it
     var BridgeObject = window.JSInterface || {
diff --git a/sdk/src/main/java/com/hcaptcha/sdk/HCaptcha.java b/sdk/src/main/java/com/hcaptcha/sdk/HCaptcha.java
index 0c234d2b..83778725 100644
--- a/sdk/src/main/java/com/hcaptcha/sdk/HCaptcha.java
+++ b/sdk/src/main/java/com/hcaptcha/sdk/HCaptcha.java
@@ -4,14 +4,13 @@
 import android.content.pm.ApplicationInfo;
 import android.content.pm.PackageManager;
 import android.os.Bundle;
-
-import lombok.NonNull;
 import androidx.annotation.Nullable;
 import androidx.fragment.app.FragmentActivity;
-import com.hcaptcha.sdk.tasks.Task;
 
+import com.hcaptcha.sdk.tasks.Task;
+import lombok.NonNull;
 
-public class HCaptcha extends Task<HCaptchaTokenResponse> implements IHCaptcha {
+public final class HCaptcha extends Task<HCaptchaTokenResponse> implements IHCaptcha {
     public static final String META_SITE_KEY = "com.hcaptcha.sdk.site-key";
     public static final String TAG = "hCaptcha";
 
@@ -42,9 +41,10 @@ public static HCaptcha getClient(@NonNull final Context context) {
     public HCaptcha setup() {
         final String siteKey;
         try {
-            String packageName = activity.getPackageName();
-            ApplicationInfo app = activity.getPackageManager().getApplicationInfo(packageName, PackageManager.GET_META_DATA);
-            Bundle bundle = app.metaData;
+            final String packageName = activity.getPackageName();
+            final ApplicationInfo app = activity.getPackageManager().getApplicationInfo(
+                    packageName, PackageManager.GET_META_DATA);
+            final Bundle bundle = app.metaData;
             siteKey = bundle.getString(META_SITE_KEY);
         } catch (PackageManager.NameNotFoundException e) {
             throw new IllegalStateException(e);
@@ -62,32 +62,34 @@ public HCaptcha setup(@NonNull final String siteKey) {
     }
 
     @Override
-    public HCaptcha setup(@NonNull HCaptchaConfig config) {
+    public HCaptcha setup(@NonNull final HCaptchaConfig inputConfig) {
         final HCaptchaStateListener listener = new HCaptchaStateListener() {
             @Override
             void onOpen() {
                 captchaOpened();
             }
+
             @Override
-            void onSuccess(final HCaptchaTokenResponse hCaptchaTokenResponse) {
-                setResult(hCaptchaTokenResponse);
+            void onSuccess(final HCaptchaTokenResponse response) {
+                setResult(response);
             }
+
             @Override
-            void onFailure(final HCaptchaException hCaptchaException) {
-                setException(hCaptchaException);
+            void onFailure(final HCaptchaException exception) {
+                setException(exception);
             }
         };
-        if (config.getHideDialog()) {
+        if (inputConfig.getHideDialog()) {
             // Overwrite certain config values in case the dialog is hidden to avoid behavior collision
-            config = config.toBuilder()
+            this.config = inputConfig.toBuilder()
                     .size(HCaptchaSize.INVISIBLE)
                     .loading(false)
                     .build();
-            captchaVerifier = new HCaptchaHeadlessWebView(activity, config, listener);
+            captchaVerifier = new HCaptchaHeadlessWebView(activity, this.config, listener);
         } else {
-            captchaVerifier = HCaptchaDialogFragment.newInstance(config, listener);
+            captchaVerifier = HCaptchaDialogFragment.newInstance(inputConfig, listener);
+            this.config = inputConfig;
         }
-        this.config = config;
         return this;
     }
 
@@ -97,6 +99,7 @@ public HCaptcha verifyWithHCaptcha() {
             // Cold start at verification time.
             setup();
         }
+        assert captchaVerifier != null;
         captchaVerifier.startVerification(activity);
         return this;
     }
@@ -108,17 +111,19 @@ public HCaptcha verifyWithHCaptcha(@NonNull final String siteKey) {
             // Or new sitekey detected, thus new setup is needed.
             setup(siteKey);
         }
+        assert captchaVerifier != null;
         captchaVerifier.startVerification(activity);
         return this;
     }
 
     @Override
-    public HCaptcha verifyWithHCaptcha(@NonNull final HCaptchaConfig config) {
-        if (captchaVerifier == null || !config.equals(this.config)) {
+    public HCaptcha verifyWithHCaptcha(@NonNull final HCaptchaConfig inputConfig) {
+        if (captchaVerifier == null || !inputConfig.equals(this.config)) {
             // Cold start at verification time.
             // Or new config detected, thus new setup is needed.
-            setup(config);
+            setup(inputConfig);
         }
+        assert captchaVerifier != null;
         captchaVerifier.startVerification(activity);
         return this;
     }
diff --git a/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaDebugInfo.java b/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaDebugInfo.java
index d5bd916b..fae1c4d4 100644
--- a/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaDebugInfo.java
+++ b/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaDebugInfo.java
@@ -6,81 +6,145 @@
 import android.webkit.JavascriptInterface;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
+import dalvik.system.DexFile;
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NonNull;
 
+import java.io.BufferedReader;
 import java.io.IOException;
+import java.io.InputStreamReader;
 import java.io.Serializable;
 import java.math.BigInteger;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 import java.util.ArrayList;
 import java.util.Enumeration;
+import java.util.HashMap;
 import java.util.List;
-
-import dalvik.system.DexFile;
-import lombok.Data;
-import lombok.NonNull;
-import lombok.RequiredArgsConstructor;
+import java.util.Map;
 
 
 /**
  * Debug info for CI.
  */
 @Data
-@RequiredArgsConstructor
-class HCaptchaDebugInfo implements Serializable {
-
+@AllArgsConstructor
+final class HCaptchaDebugInfo implements Serializable {
     public static final String JS_INTERFACE_TAG = "JSDI";
+    private static final String GET_PROP_BIN = "/system/bin/getprop";
 
-    private static String cache;
+    private static String sDebugInfo;
+    private static String sSysDebug;
 
     @NonNull
     private final Context context;
 
     @JavascriptInterface
     public String getDebugInfo() {
-        if (cache != null) {
-            return cache;
+        if (sDebugInfo != null) {
+            return sDebugInfo;
         }
         synchronized (this) {
-            if (cache != null) {
-                return cache;
+            if (sDebugInfo != null) {
+                return sDebugInfo;
             }
 
             try {
-                List<String> debugInfo = debugInfo(context.getPackageName(), context.getPackageCodePath());
+                final List<String> debugInfo = debugInfo(context.getPackageName(), context.getPackageCodePath());
                 final ObjectMapper objectMapper = new ObjectMapper();
-                cache = objectMapper.writeValueAsString(debugInfo);
-            } catch (IOException | NoSuchAlgorithmException | CloneNotSupportedException e) {
+                sDebugInfo = objectMapper.writeValueAsString(debugInfo);
+            } catch (IOException | NoSuchAlgorithmException e) {
                 Log.d(JS_INTERFACE_TAG, "Cannot build debugInfo");
                 return "[]";
             }
-            return cache;
+            return sDebugInfo;
+        }
+    }
+
+    @JavascriptInterface
+    public String getSysDebug() {
+        if (sSysDebug != null) {
+            return sSysDebug;
+        }
+        synchronized (this) {
+            if (sSysDebug != null) {
+                return sSysDebug;
+            }
+
+            try {
+                final Map<String, String> props = roBuildProps();
+                final ObjectMapper objectMapper = new ObjectMapper();
+                sSysDebug = objectMapper.writeValueAsString(props);
+            } catch (IOException e) {
+                Log.d(JS_INTERFACE_TAG, "Cannot build sysDebug");
+                return "{}";
+            }
+            return sSysDebug;
         }
     }
 
     private List<String> debugInfo(String packageName, String packageCode)
-            throws IOException, NoSuchAlgorithmException, CloneNotSupportedException {
-        List<String> result = new ArrayList<>(512);
-        DexFile dexFile = new DexFile(packageCode);
-        Enumeration<String> classes = dexFile.entries();
-        MessageDigest androidMd5 = MessageDigest.getInstance("MD5");
-        MessageDigest appMd5 = MessageDigest.getInstance("MD5");
-        MessageDigest depsMd5 = MessageDigest.getInstance("MD5");
-        while (classes.hasMoreElements()) {
-            String cls = classes.nextElement();
-            if (cls.startsWith("com.google.android.") || cls.startsWith("android.")) {
-                androidMd5.update(cls.getBytes("UTF-8"));
-            } else if (cls.startsWith(packageName)) {
-                appMd5.update(cls.getBytes("UTF-8"));
-            } else {
-                depsMd5.update(cls.getBytes("UTF-8"));
+            throws IOException, NoSuchAlgorithmException {
+        final List<String> result = new ArrayList<>(512);
+        final MessageDigest androidMd5 = MessageDigest.getInstance("MD5");
+        final MessageDigest appMd5 = MessageDigest.getInstance("MD5");
+        final MessageDigest depsMd5 = MessageDigest.getInstance("MD5");
+        final DexFile dexFile = new DexFile(packageCode);
+        try {
+            final String charsetName = "UTF-8";
+            final Enumeration<String> classes = dexFile.entries();
+            while (classes.hasMoreElements()) {
+                final String cls = classes.nextElement();
+                if (cls.startsWith("com.google.android.") || cls.startsWith("android.")) {
+                    androidMd5.update(cls.getBytes(charsetName));
+                } else if (cls.startsWith(packageName)) {
+                    appMd5.update(cls.getBytes(charsetName));
+                } else {
+                    depsMd5.update(cls.getBytes(charsetName));
+                }
             }
+        } finally {
+            dexFile.close();
         }
-        result.add("sys_" + String.format("%032x", new BigInteger(1, androidMd5.digest())));
-        result.add("deps_" + String.format("%032x", new BigInteger(1, depsMd5.digest())));
-        result.add("app_" + String.format("%032x", new BigInteger(1, appMd5.digest())));
+        final String hexFormat = "%032x";
+        result.add("sys_" + String.format(hexFormat, new BigInteger(1, androidMd5.digest())));
+        result.add("deps_" + String.format(hexFormat, new BigInteger(1, depsMd5.digest())));
+        result.add("app_" + String.format(hexFormat, new BigInteger(1, appMd5.digest())));
         result.add("aver_" + Build.VERSION.RELEASE);
         result.add("sdk_" + BuildConfig.VERSION_NAME.replace('.', '_'));
         return result;
     }
+
+    private Map<String, String> roBuildProps() throws IOException {
+        Process getpropProcess = null;
+        final Map<String, String> props = new HashMap<>();
+        try {
+            getpropProcess = new ProcessBuilder(GET_PROP_BIN).start();
+            try (BufferedReader br = new BufferedReader(
+                    new InputStreamReader(getpropProcess.getInputStream(), "UTF-8"))) {
+                String line;
+                final StringBuilder entry = new StringBuilder();
+                while ((line = br.readLine()) != null) {
+                    if (line.endsWith("]")) {
+                        entry.replace(0, entry.length() == 0 ? 0 : entry.length() - 1, line);
+                    } else {
+                        entry.append(line);
+                        continue;
+                    }
+                    final String[] parsedLine = entry.toString().split("]: \\[");
+                    final String key = parsedLine[0].substring(1); // strip first [
+                    if (key.startsWith("ro")) {
+                        final String value = parsedLine[1].substring(0, parsedLine[1].length() - 2); // strip last ]
+                        props.put(key, value);
+                    }
+                }
+            }
+        } finally {
+            if (getpropProcess != null) {
+                getpropProcess.destroy();
+            }
+        }
+        return props;
+    }
 }
diff --git a/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaDialogFragment.java b/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaDialogFragment.java
index 082cee8f..3920b6d1 100644
--- a/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaDialogFragment.java
+++ b/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaDialogFragment.java
@@ -11,7 +11,11 @@
 import android.os.Handler;
 import android.os.Looper;
 import android.util.Log;
-import android.view.*;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.view.Window;
+import android.view.WindowManager;
 import android.webkit.WebView;
 import android.widget.LinearLayout;
 import androidx.annotation.Nullable;
@@ -19,6 +23,7 @@
 import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentActivity;
 import androidx.fragment.app.FragmentManager;
+
 import lombok.NonNull;
 
 
@@ -81,6 +86,7 @@ public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container,
         final HCaptchaStateListener listener;
         try {
             listener = getArguments().getParcelable(KEY_LISTENER);
+            assert listener != null;
         } catch (BadParcelableException e) {
             // Happens when fragment tries to reconstruct because the activity was killed
             // And thus there is no way of communicating back
@@ -88,10 +94,12 @@ public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container,
             return rootView;
         }
         final HCaptchaConfig config = (HCaptchaConfig) getArguments().getSerializable(KEY_CONFIG);
+        assert config != null;
         final WebView webView = rootView.findViewById(R.id.webView);
         loadingContainer = rootView.findViewById(R.id.loadingContainer);
         loadingContainer.setVisibility(config.getLoading() ? View.VISIBLE : View.GONE);
-        webViewHelper = new HCaptchaWebViewHelper(new Handler(Looper.getMainLooper()), requireContext(), config, this, listener, webView);
+        webViewHelper = new HCaptchaWebViewHelper(
+                new Handler(Looper.getMainLooper()), requireContext(), config, this, listener, webView);
         return rootView;
     }
 
@@ -153,10 +161,10 @@ public void onOpen() {
     }
 
     @Override
-    public void onFailure(@NonNull final HCaptchaException hCaptchaException) {
+    public void onFailure(@NonNull final HCaptchaException exception) {
         final boolean silentRetry = webViewHelper != null
                 && webViewHelper.getConfig().getResetOnTimeout()
-                && hCaptchaException.getHCaptchaError() == HCaptchaError.SESSION_TIMEOUT;
+                && exception.getHCaptchaError() == HCaptchaError.SESSION_TIMEOUT;
         if (isAdded() && !silentRetry) {
             dismiss();
         }
@@ -164,18 +172,18 @@ public void onFailure(@NonNull final HCaptchaException hCaptchaException) {
             if (silentRetry) {
                 webViewHelper.getWebView().loadUrl("javascript:resetAndExecute();");
             } else {
-                webViewHelper.getListener().onFailure(hCaptchaException);
+                webViewHelper.getListener().onFailure(exception);
             }
         }
     }
 
     @Override
-    public void onSuccess(final HCaptchaTokenResponse hCaptchaTokenResponse) {
+    public void onSuccess(final HCaptchaTokenResponse tokenResponse) {
         assert webViewHelper != null;
         if (isAdded()) {
             dismiss();
         }
-        webViewHelper.getListener().onSuccess(hCaptchaTokenResponse);
+        webViewHelper.getListener().onSuccess(tokenResponse);
     }
 
     @Override
diff --git a/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaError.java b/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaError.java
index 8901996b..c74f9343 100644
--- a/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaError.java
+++ b/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaError.java
@@ -15,7 +15,8 @@ public enum HCaptchaError implements Serializable {
     /**
      * Internet connection is missing.
      *
-     * Make sure AndroidManifest requires internet permission: {@code {@literal <}uses-permission android:name="android.permission.INTERNET" /{@literal >}}
+     * Make sure AndroidManifest requires internet permission:
+     * {@code {@literal <}uses-permission android:name="android.permission.INTERNET" /{@literal >}}
      */
     NETWORK_ERROR(7, "No internet connection"),
 
@@ -25,12 +26,14 @@ public enum HCaptchaError implements Serializable {
     INVALID_DATA(8, "Invalid data is not accepted by endpoints"),
 
     /**
-     * User may need to select the checkbox or if invisible programmatically call execute to initiate the challenge again.
+     * User may need to select the checkbox or if invisible programmatically call execute to
+     * initiate the challenge again.
      */
     CHALLENGE_ERROR(9, "Challenge encountered error on setup"),
 
     /**
-     * User may need to select the checkbox or if invisible programmatically call execute to initiate the challenge again.
+     * User may need to select the checkbox or if invisible programmatically call execute to
+     * initiate the challenge again.
      */
     INTERNAL_ERROR(10, "hCaptcha client encountered an internal error"),
 
diff --git a/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaException.java b/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaException.java
index 3593ab5d..89b928e0 100644
--- a/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaException.java
+++ b/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaException.java
@@ -1,6 +1,7 @@
 package com.hcaptcha.sdk;
 
 import androidx.annotation.Nullable;
+
 import lombok.AllArgsConstructor;
 import lombok.Data;
 import lombok.EqualsAndHashCode;
diff --git a/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaHeadlessWebView.java b/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaHeadlessWebView.java
index 3a46c9f4..d7af8c9f 100644
--- a/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaHeadlessWebView.java
+++ b/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaHeadlessWebView.java
@@ -6,6 +6,7 @@
 import android.view.ViewGroup;
 import android.webkit.WebView;
 import androidx.fragment.app.FragmentActivity;
+
 import lombok.Getter;
 import lombok.NonNull;
 
@@ -23,9 +24,9 @@ final class HCaptchaHeadlessWebView implements IHCaptchaVerifier {
     private boolean webViewLoaded;
     private boolean shouldExecuteOnLoad;
 
-    public HCaptchaHeadlessWebView(@NonNull FragmentActivity activity,
-                                   @NonNull final HCaptchaConfig config,
-                                   @NonNull final HCaptchaStateListener listener) {
+    HCaptchaHeadlessWebView(@NonNull FragmentActivity activity,
+                            @NonNull final HCaptchaConfig config,
+                            @NonNull final HCaptchaStateListener listener) {
         this.config = config;
         this.listener = listener;
         final WebView webView = new WebView(activity);
@@ -35,7 +36,8 @@ public HCaptchaHeadlessWebView(@NonNull FragmentActivity activity,
             final ViewGroup rootView = (ViewGroup) activity.getWindow().getDecorView().getRootView();
             rootView.addView(webView);
         }
-        webViewHelper = new HCaptchaWebViewHelper(new Handler(Looper.getMainLooper()), activity, config, this, listener, webView);
+        webViewHelper = new HCaptchaWebViewHelper(
+                new Handler(Looper.getMainLooper()), activity, config, this, listener, webView);
     }
 
     @Override
@@ -53,19 +55,19 @@ private void resetAndExecute() {
     }
 
     @Override
-    public void onFailure(final HCaptchaException hCaptchaException) {
+    public void onFailure(final HCaptchaException exception) {
         final boolean silentRetry = webViewHelper.getConfig().getResetOnTimeout()
-                && hCaptchaException.getHCaptchaError() == HCaptchaError.SESSION_TIMEOUT;
+                && exception.getHCaptchaError() == HCaptchaError.SESSION_TIMEOUT;
         if (silentRetry) {
             resetAndExecute();
         } else {
-            listener.onFailure(hCaptchaException);
+            listener.onFailure(exception);
         }
     }
 
     @Override
-    public void onSuccess(final HCaptchaTokenResponse hCaptchaTokenResponse) {
-        listener.onSuccess(hCaptchaTokenResponse);
+    public void onSuccess(final HCaptchaTokenResponse tokenResponse) {
+        listener.onSuccess(tokenResponse);
     }
 
     @Override
diff --git a/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaJSInterface.java b/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaJSInterface.java
index e09bbaec..212f54ce 100644
--- a/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaJSInterface.java
+++ b/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaJSInterface.java
@@ -2,6 +2,7 @@
 
 import android.os.Handler;
 import android.webkit.JavascriptInterface;
+
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import lombok.AllArgsConstructor;
diff --git a/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaSize.java b/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaSize.java
index f5df809d..bfd63b43 100644
--- a/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaSize.java
+++ b/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaSize.java
@@ -1,6 +1,7 @@
 package com.hcaptcha.sdk;
 
 import androidx.annotation.NonNull;
+
 import com.fasterxml.jackson.annotation.JsonValue;
 
 import java.io.Serializable;
diff --git a/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaStateListener.java b/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaStateListener.java
index 71945518..a21eff76 100644
--- a/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaStateListener.java
+++ b/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaStateListener.java
@@ -5,9 +5,9 @@
 
 abstract class HCaptchaStateListener implements Parcelable {
 
-    abstract void onSuccess(HCaptchaTokenResponse hCaptchaTokenResponse);
+    abstract void onSuccess(HCaptchaTokenResponse tokenResponse);
 
-    abstract void onFailure(HCaptchaException hCaptchaException);
+    abstract void onFailure(HCaptchaException exception);
 
     abstract void onOpen();
 
@@ -18,6 +18,6 @@ public int describeContents() {
 
     @Override
     public void writeToParcel(Parcel dest, int flags) {
-
+        // nothing to persist
     }
 }
diff --git a/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaTheme.java b/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaTheme.java
index 3806f773..430901df 100644
--- a/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaTheme.java
+++ b/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaTheme.java
@@ -1,6 +1,7 @@
 package com.hcaptcha.sdk;
 
 import androidx.annotation.NonNull;
+
 import com.fasterxml.jackson.annotation.JsonValue;
 
 import java.io.Serializable;
diff --git a/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaWebViewHelper.java b/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaWebViewHelper.java
index efe85552..70237726 100644
--- a/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaWebViewHelper.java
+++ b/sdk/src/main/java/com/hcaptcha/sdk/HCaptchaWebViewHelper.java
@@ -10,6 +10,7 @@
 import android.view.ViewParent;
 import android.webkit.WebSettings;
 import android.webkit.WebView;
+
 import lombok.Getter;
 import lombok.NonNull;
 
@@ -19,8 +20,8 @@ final class HCaptchaWebViewHelper {
     @NonNull
     private final Context context;
 
-    @Getter
     @NonNull
+    @Getter
     private final HCaptchaConfig config;
 
     @NonNull
@@ -34,12 +35,12 @@ final class HCaptchaWebViewHelper {
     @NonNull
     private final WebView webView;
 
-    public HCaptchaWebViewHelper(@NonNull final Handler handler,
-                                 @NonNull final Context context,
-                                 @NonNull final HCaptchaConfig config,
-                                 @NonNull final IHCaptchaVerifier captchaVerifier,
-                                 @NonNull final HCaptchaStateListener listener,
-                                 @NonNull final WebView webView) {
+    HCaptchaWebViewHelper(@NonNull final Handler handler,
+                          @NonNull final Context context,
+                          @NonNull final HCaptchaConfig config,
+                          @NonNull final IHCaptchaVerifier captchaVerifier,
+                          @NonNull final HCaptchaStateListener listener,
+                          @NonNull final WebView webView) {
         this.context = context;
         this.config = config;
         this.captchaVerifier = captchaVerifier;
diff --git a/sdk/src/main/java/com/hcaptcha/sdk/IHCaptcha.java b/sdk/src/main/java/com/hcaptcha/sdk/IHCaptcha.java
index a3239edf..43b0f0eb 100644
--- a/sdk/src/main/java/com/hcaptcha/sdk/IHCaptcha.java
+++ b/sdk/src/main/java/com/hcaptcha/sdk/IHCaptcha.java
@@ -50,7 +50,7 @@ public interface IHCaptcha {
      * @param siteKey The hCaptcha site-key. Get one here <a href="https://www.hcaptcha.com">hcaptcha.com</a>
      * @return new {@link HCaptcha} object
      */
-    HCaptcha setup(@NonNull final String siteKey);
+    HCaptcha setup(@NonNull String siteKey);
 
     /**
      * Constructs a new client which allows to display a challenge dialog
@@ -58,7 +58,7 @@ public interface IHCaptcha {
      * @param config Config to customize: size, theme, locale, endpoint, rqdata, etc.
      * @return new {@link HCaptcha} object
      */
-    HCaptcha setup(@NonNull final HCaptchaConfig config);
+    HCaptcha setup(@NonNull HCaptchaConfig config);
 
     /**
      * Shows a captcha challenge dialog to be completed by the user
@@ -73,7 +73,7 @@ public interface IHCaptcha {
      * @param siteKey The hCaptcha site-key. Get one here <a href="https://www.hcaptcha.com">hcaptcha.com</a>
      * @return {@link HCaptcha}
      */
-    HCaptcha verifyWithHCaptcha(@NonNull final String siteKey);
+    HCaptcha verifyWithHCaptcha(@NonNull String siteKey);
 
 
     /**
@@ -82,6 +82,6 @@ public interface IHCaptcha {
      * @param config Config to customize: size, theme, locale, endpoint, rqdata, etc.
      * @return {@link HCaptcha}
      */
-    HCaptcha verifyWithHCaptcha(@NonNull final HCaptchaConfig config);
+    HCaptcha verifyWithHCaptcha(@NonNull HCaptchaConfig config);
 
 }
diff --git a/sdk/src/main/java/com/hcaptcha/sdk/IHCaptchaVerifier.java b/sdk/src/main/java/com/hcaptcha/sdk/IHCaptchaVerifier.java
index 48056e00..a524521b 100644
--- a/sdk/src/main/java/com/hcaptcha/sdk/IHCaptchaVerifier.java
+++ b/sdk/src/main/java/com/hcaptcha/sdk/IHCaptchaVerifier.java
@@ -1,6 +1,7 @@
 package com.hcaptcha.sdk;
 
 import androidx.fragment.app.FragmentActivity;
+
 import com.hcaptcha.sdk.tasks.OnFailureListener;
 import com.hcaptcha.sdk.tasks.OnLoadedListener;
 import com.hcaptcha.sdk.tasks.OnOpenListener;
diff --git a/sdk/src/main/java/com/hcaptcha/sdk/tasks/OnFailureListener.java b/sdk/src/main/java/com/hcaptcha/sdk/tasks/OnFailureListener.java
index 3a24df3e..cf5fe359 100644
--- a/sdk/src/main/java/com/hcaptcha/sdk/tasks/OnFailureListener.java
+++ b/sdk/src/main/java/com/hcaptcha/sdk/tasks/OnFailureListener.java
@@ -11,8 +11,8 @@ public interface OnFailureListener {
     /**
      * Called whenever there is a hCaptcha error or user closed the challenge dialog
      *
-     * @param hCaptchaException the exception
+     * @param exception the exception
      */
-    void onFailure(HCaptchaException hCaptchaException);
+    void onFailure(HCaptchaException exception);
 
 }
diff --git a/sdk/src/main/java/com/hcaptcha/sdk/tasks/OnSuccessListener.java b/sdk/src/main/java/com/hcaptcha/sdk/tasks/OnSuccessListener.java
index b8e9fc91..49363d2f 100644
--- a/sdk/src/main/java/com/hcaptcha/sdk/tasks/OnSuccessListener.java
+++ b/sdk/src/main/java/com/hcaptcha/sdk/tasks/OnSuccessListener.java
@@ -11,8 +11,8 @@ public interface OnSuccessListener<TResult> {
     /**
      * Called when the challenge is successfully completed
      *
-     * @param tResult the hCaptcha token result
+     * @param result the hCaptcha token result
      */
-    void onSuccess(TResult tResult);
+    void onSuccess(TResult result);
 
 }
diff --git a/sdk/src/main/java/com/hcaptcha/sdk/tasks/Task.java b/sdk/src/main/java/com/hcaptcha/sdk/tasks/Task.java
index 673600f7..9fc22907 100644
--- a/sdk/src/main/java/com/hcaptcha/sdk/tasks/Task.java
+++ b/sdk/src/main/java/com/hcaptcha/sdk/tasks/Task.java
@@ -2,10 +2,10 @@
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
+
 import com.hcaptcha.sdk.HCaptchaException;
 
 import java.util.ArrayList;
-import java.util.Iterator;
 import java.util.List;
 
 
@@ -92,10 +92,10 @@ protected void setResult(TResult result) {
     /**
      * Sets the task exception and marks it as not successfully completed
      *
-     * @param hCaptchaException the hCaptcha exception
+     * @param exception the hCaptcha exception
      */
-    protected void setException(@NonNull HCaptchaException hCaptchaException) {
-        this.hCaptchaException = hCaptchaException;
+    protected void setException(@NonNull HCaptchaException exception) {
+        this.hCaptchaException = exception;
         this.successful = false;
         this.complete = true;
         tryCb();
diff --git a/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaConfigTest.java b/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaConfigTest.java
index da29e05c..e4e84f39 100644
--- a/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaConfigTest.java
+++ b/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaConfigTest.java
@@ -1,12 +1,11 @@
 package com.hcaptcha.sdk;
 
-import org.junit.Test;
-
-import java.util.Locale;
-
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNull;
 
+import org.junit.Test;
+
+import java.util.Locale;
 
 public class HCaptchaConfigTest {
 
@@ -40,9 +39,9 @@ public void custom_config() {
         final String customLocale = "ro";
         final Boolean sentry = false;
         final String customTheme = "{ \"palette\": {"
-            + "\"mode\": \"light\", \"primary\": { \"main\": \"#F16622\" },"
-            + "\"warn\": {  \"main\": \"#F16622\" },"
-            + "\"text\": { \"heading\": \"#F16622\", \"body\": \"#F16622\" } } }";
+                + "\"mode\": \"light\", \"primary\": { \"main\": \"#F16622\" },"
+                + "\"warn\": {  \"main\": \"#F16622\" },"
+                + "\"text\": { \"heading\": \"#F16622\", \"body\": \"#F16622\" } } }";
 
         final HCaptchaConfig config = HCaptchaConfig.builder()
                 .siteKey(MOCK_SITE_KEY)
diff --git a/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaErrorTest.java b/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaErrorTest.java
index b57f7950..96a26393 100644
--- a/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaErrorTest.java
+++ b/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaErrorTest.java
@@ -1,11 +1,11 @@
 package com.hcaptcha.sdk;
 
-import org.junit.Test;
-import org.junit.function.ThrowingRunnable;
-
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertThrows;
 
+import org.junit.Test;
+import org.junit.function.ThrowingRunnable;
+
 public class HCaptchaErrorTest {
 
     @Test
@@ -18,6 +18,7 @@ public void enum_codes() {
     }
 
     @Test
+    @SuppressWarnings("magicnumber")
     public void enum_ids() {
         assertEquals(7, HCaptchaError.NETWORK_ERROR.getErrorId());
         assertEquals(15, HCaptchaError.SESSION_TIMEOUT.getErrorId());
@@ -27,6 +28,7 @@ public void enum_ids() {
     }
 
     @Test
+    @SuppressWarnings("checkstyle:magicnumber")
     public void get_enum_from_id() {
         assertEquals(HCaptchaError.NETWORK_ERROR, HCaptchaError.fromId(7));
         assertEquals(HCaptchaError.SESSION_TIMEOUT, HCaptchaError.fromId(15));
@@ -36,6 +38,7 @@ public void get_enum_from_id() {
     }
 
     @Test
+    @SuppressWarnings("checkstyle:MagicNumber")
     public void get_enum_from_invalid_id_throws() {
         assertThrows(RuntimeException.class, new ThrowingRunnable() {
             @Override
@@ -44,5 +47,4 @@ public void run() {
             }
         });
     }
-
 }
diff --git a/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaExceptionTest.java b/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaExceptionTest.java
index 40fac973..69c8164b 100644
--- a/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaExceptionTest.java
+++ b/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaExceptionTest.java
@@ -1,21 +1,20 @@
 package com.hcaptcha.sdk;
 
-import org.junit.Test;
-
 import static org.junit.Assert.assertEquals;
 
+import org.junit.Test;
+
 public class HCaptchaExceptionTest {
 
     @Test
     public void exception_matches_error() {
-        final HCaptchaError hCaptchaError = HCaptchaError.NETWORK_ERROR;
+        final HCaptchaError error = HCaptchaError.NETWORK_ERROR;
         try {
-            throw new HCaptchaException(hCaptchaError);
+            throw new HCaptchaException(error);
         } catch (HCaptchaException hCaptchaException1) {
-            assertEquals(hCaptchaError.getErrorId(), hCaptchaException1.getStatusCode());
-            assertEquals(hCaptchaError.getMessage(), hCaptchaException1.getMessage());
-            assertEquals(hCaptchaError, hCaptchaException1.getHCaptchaError());
+            assertEquals(error.getErrorId(), hCaptchaException1.getStatusCode());
+            assertEquals(error.getMessage(), hCaptchaException1.getMessage());
+            assertEquals(error, hCaptchaException1.getHCaptchaError());
         }
     }
-
 }
diff --git a/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaJSInterfaceTest.java b/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaJSInterfaceTest.java
index 57ea8dc1..0915bf2e 100644
--- a/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaJSInterfaceTest.java
+++ b/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaJSInterfaceTest.java
@@ -1,6 +1,14 @@
 package com.hcaptcha.sdk;
 
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
 import android.os.Handler;
+
 import com.fasterxml.jackson.core.JsonProcessingException;
 import org.json.JSONException;
 import org.json.JSONObject;
@@ -16,12 +24,6 @@
 import org.mockito.stubbing.Answer;
 import org.skyscreamer.jsonassert.JSONAssert;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotNull;
-import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.Mockito.*;
-
-
 @RunWith(MockitoJUnitRunner.class)
 public class HCaptchaJSInterfaceTest {
 
@@ -77,9 +79,9 @@ public void full_config_serialization() throws JsonProcessingException, JSONExce
                 .resetOnTimeout(true)
                 .hideDialog(true)
                 .build();
-        final HCaptchaJSInterface HCaptchaJsInterface = new HCaptchaJSInterface(handler, config, captchaVerifier);
+        final HCaptchaJSInterface jsInterface = new HCaptchaJSInterface(handler, config, captchaVerifier);
 
-        JSONObject expected = new JSONObject();
+        final JSONObject expected = new JSONObject();
         expected.put("siteKey", siteKey);
         expected.put("sentry", true);
         expected.put("loading", true);
@@ -97,7 +99,7 @@ public void full_config_serialization() throws JsonProcessingException, JSONExce
         expected.put("resetOnTimeout", true);
         expected.put("hideDialog", true);
 
-        JSONAssert.assertEquals(HCaptchaJsInterface.getConfig(), expected, false);
+        JSONAssert.assertEquals(jsInterface.getConfig(), expected, false);
     }
 
     @Test
@@ -113,9 +115,9 @@ public void subset_config_serialization() throws JsonProcessingException, JSONEx
                 .theme(HCaptchaTheme.DARK)
                 .rqdata(rqdata)
                 .build();
-        final HCaptchaJSInterface HCaptchaJsInterface = new HCaptchaJSInterface(handler, config, captchaVerifier);
+        final HCaptchaJSInterface jsInterface = new HCaptchaJSInterface(handler, config, captchaVerifier);
 
-        JSONObject expected = new JSONObject();
+        final JSONObject expected = new JSONObject();
         expected.put("siteKey", siteKey);
         expected.put("sentry", true);
         expected.put("loading", true);
@@ -133,28 +135,28 @@ public void subset_config_serialization() throws JsonProcessingException, JSONEx
         expected.put("resetOnTimeout", false);
         expected.put("hideDialog", false);
 
-        JSONAssert.assertEquals(HCaptchaJsInterface.getConfig(), expected, false);
+        JSONAssert.assertEquals(jsInterface.getConfig(), expected, false);
     }
 
     @Test
     public void calls_on_challenge_ready() {
-        final HCaptchaJSInterface hCaptchaJSInterface = new HCaptchaJSInterface(handler, testConfig, captchaVerifier);
-        hCaptchaJSInterface.onLoaded();
+        final HCaptchaJSInterface jsInterface = new HCaptchaJSInterface(handler, testConfig, captchaVerifier);
+        jsInterface.onLoaded();
         verify(captchaVerifier, times(1)).onLoaded();
     }
 
     @Test
     public void calls_on_challenge_visible_cb() {
-        final HCaptchaJSInterface hCaptchaJSInterface = new HCaptchaJSInterface(handler, testConfig, captchaVerifier);
-        hCaptchaJSInterface.onOpen();
+        final HCaptchaJSInterface jsInterface = new HCaptchaJSInterface(handler, testConfig, captchaVerifier);
+        jsInterface.onOpen();
         verify(captchaVerifier, times(1)).onOpen();
     }
 
     @Test
     public void on_pass_forwards_token_to_listeners() {
         final String token = "mock-token";
-        final HCaptchaJSInterface hCaptchaJSInterface = new HCaptchaJSInterface(handler, testConfig, captchaVerifier);
-        hCaptchaJSInterface.onPass(token);
+        final HCaptchaJSInterface jsInterface = new HCaptchaJSInterface(handler, testConfig, captchaVerifier);
+        jsInterface.onPass(token);
         verify(captchaVerifier, times(1)).onSuccess(tokenCaptor.capture());
         assertEquals(token, tokenCaptor.getValue().getTokenResult());
     }
@@ -162,8 +164,8 @@ public void on_pass_forwards_token_to_listeners() {
     @Test
     public void on_error_forwards_error_to_listeners() {
         final HCaptchaError error = HCaptchaError.CHALLENGE_CLOSED;
-        final HCaptchaJSInterface hCaptchaJSInterface = new HCaptchaJSInterface(handler, testConfig, captchaVerifier);
-        hCaptchaJSInterface.onError(error.getErrorId());
+        final HCaptchaJSInterface jsInterface = new HCaptchaJSInterface(handler, testConfig, captchaVerifier);
+        jsInterface.onError(error.getErrorId());
         verify(captchaVerifier, times(1)).onFailure(exceptionCaptor.capture());
         assertEquals(error.getMessage(), exceptionCaptor.getValue().getMessage());
         assertNotNull(exceptionCaptor.getValue());
diff --git a/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaSizeTest.java b/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaSizeTest.java
index c4f314d8..5e7a800a 100644
--- a/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaSizeTest.java
+++ b/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaSizeTest.java
@@ -1,11 +1,11 @@
 package com.hcaptcha.sdk;
 
+import static org.junit.Assert.assertEquals;
+
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import org.junit.Test;
 
-import static org.junit.Assert.assertEquals;
-
 public class HCaptchaSizeTest {
 
     @Test
diff --git a/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaTest.java b/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaTest.java
index ff1e7e10..bdc1f28a 100644
--- a/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaTest.java
+++ b/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaTest.java
@@ -1,11 +1,21 @@
 package com.hcaptcha.sdk;
 
 import static com.hcaptcha.sdk.HCaptcha.META_SITE_KEY;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.mockStatic;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
 
 import android.content.pm.ApplicationInfo;
 import android.content.pm.PackageManager;
 import android.os.Bundle;
-
 import androidx.fragment.app.FragmentActivity;
 
 import org.junit.After;
@@ -21,16 +31,6 @@
 
 import java.util.Locale;
 
-import static org.junit.Assert.*;
-import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.ArgumentMatchers.anyInt;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.mockStatic;
-import static org.mockito.Mockito.never;
-import static org.mockito.Mockito.times;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
-
 
 @RunWith(MockitoJUnitRunner.class)
 public class HCaptchaTest {
@@ -82,8 +82,8 @@ public void test_fragment_creation_via_activity() {
 
     @Test
     public void test_site_key_from_metadata() throws Exception {
-        ApplicationInfo applicationInfo = mock(ApplicationInfo.class);
-        Bundle bundle = mock(Bundle.class);
+        final ApplicationInfo applicationInfo = mock(ApplicationInfo.class);
+        final Bundle bundle = mock(Bundle.class);
         when(bundle.getString(META_SITE_KEY)).thenReturn(HCaptchaConfigTest.MOCK_SITE_KEY);
         bundle.putString(META_SITE_KEY, HCaptchaConfigTest.MOCK_SITE_KEY);
         applicationInfo.metaData = bundle;
diff --git a/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaThemeTest.java b/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaThemeTest.java
index b341e4fa..10a1c6c3 100644
--- a/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaThemeTest.java
+++ b/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaThemeTest.java
@@ -1,11 +1,11 @@
 package com.hcaptcha.sdk;
 
+import static org.junit.Assert.assertEquals;
+
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import org.junit.Test;
 
-import static org.junit.Assert.assertEquals;
-
 public class HCaptchaThemeTest {
 
     @Test
diff --git a/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaWebViewHelperTest.java b/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaWebViewHelperTest.java
index 264c98c0..d144ab9b 100644
--- a/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaWebViewHelperTest.java
+++ b/sdk/src/test/java/com/hcaptcha/sdk/HCaptchaWebViewHelperTest.java
@@ -16,7 +16,6 @@
 import android.view.ViewParent;
 import android.webkit.WebSettings;
 import android.webkit.WebView;
-
 import androidx.annotation.NonNull;
 
 import org.junit.After;
@@ -41,7 +40,7 @@ public class HCaptchaWebViewHelperTest {
     IHCaptchaVerifier captchaVerifier;
 
     @Mock
-    HCaptchaStateListener hCaptchaStateListener;
+    HCaptchaStateListener stateListener;
 
     @Mock
     WebView webView;
@@ -61,11 +60,12 @@ public class HCaptchaWebViewHelperTest {
     public void init() {
         MockitoAnnotations.openMocks(this);
         androidLogMock = mockStatic(Log.class);
-        hCaptchaStateListener = mock(HCaptchaStateListener.class);
+        stateListener = mock(HCaptchaStateListener.class);
         webView = mock(WebView.class);
         webSettings = mock(WebSettings.class);
         when(webView.getSettings()).thenReturn(webSettings);
-        webViewHelper = new HCaptchaWebViewHelper(handler, context, config, captchaVerifier, hCaptchaStateListener, webView);
+        webViewHelper = new HCaptchaWebViewHelper(handler, context, config, captchaVerifier,
+                stateListener, webView);
     }
 
     @After
@@ -81,7 +81,7 @@ public void test_constructor() {
 
     @Test
     public void test_destroy() {
-        ViewGroup viewParent = mock(ViewGroup.class, withSettings().extraInterfaces(ViewParent.class));
+        final ViewGroup viewParent = mock(ViewGroup.class, withSettings().extraInterfaces(ViewParent.class));
         when(webView.getParent()).thenReturn(viewParent);
         webViewHelper.destroy();
         verify(viewParent).removeView(webView);