Make GzipError struct

CHANGELOG.md

@@ -8,6 +8,7 @@ Change Log
 ### Changes
 
 - Make `CompressionLevel` struct.
+- Make `GzipError` struct.
 
 
 

Sources/Data+Gzip.swift

@@ -61,111 +61,91 @@ public struct CompressionLevel: RawRepresentable, Equatable {
 /**
  Errors on gzipping/gunzipping based on the zlib error codes.
  */
-public enum GzipError: Error {
+public struct GzipError: Swift.Error {
     // cf. http://www.zlib.net/manual.html
 
-    /**
-    The stream structure was inconsistent.
-
-    - underlying zlib error: `Z_STREAM_ERROR` (-2)
-    - parameter message: returned message by zlib
-    */
-    case stream(message: String)
-
-    /**
-    The input data was corrupted (input stream not conforming to the zlib format or incorrect check value).
-
-    - underlying zlib error: `Z_DATA_ERROR` (-3)
-    - parameter message: returned message by zlib
-    */
-    case data(message: String)
-
-    /**
-    There was not enough memory.
-
-    - underlying zlib error: `Z_MEM_ERROR` (-4)
-    - parameter message: returned message by zlib
-    */
-    case memory(message: String)
-
-    /**
-    No progress is possible or there was not enough room in the output buffer.
-
-    - underlying zlib error: `Z_BUF_ERROR` (-5)
-    - parameter message: returned message by zlib
-    */
-    case buffer(message: String)
-
-    /**
-    The zlib library version is incompatible with the version assumed by the caller.
-
-    - underlying zlib error: `Z_VERSION_ERROR` (-6)
-    - parameter message: returned message by zlib
-    */
-    case version(message: String)
+    public enum Kind {
+        /**
+         The stream structure was inconsistent.
+
+         - underlying zlib error: `Z_STREAM_ERROR` (-2)
+         */
+        case stream
+
+        /**
+         The input data was corrupted (input stream not conforming to the zlib format or incorrect check value).
+
+         - underlying zlib error: `Z_DATA_ERROR` (-3)
+         */
+        case data
+
+        /**
+         There was not enough memory.
+
+         - underlying zlib error: `Z_MEM_ERROR` (-4)
+         */
+        case memory
+
+        /**
+         No progress is possible or there was not enough room in the output buffer.
+
+         - underlying zlib error: `Z_BUF_ERROR` (-5)
+         */
+        case buffer
+
+        /**
+         The zlib library version is incompatible with the version assumed by the caller.
+
+         - underlying zlib error: `Z_VERSION_ERROR` (-6)
+         */
+        case version
+
+        /**
+         An unknown error occurred.
+
+         - parameter code: return error by zlib
+         */
+        case unknown(code: Int)
+    }
 
-    /**
-    An unknown error occurred.
+    /// Error kind.
+    public let kind: Kind
 
-    - parameter message: returned message by zlib
-    - parameter code: return error by zlib
-    */
-    case unknown(message: String, code: Int)
+    /// Returned message by zlib.
+    public let message: String
 
 
     internal init(code: Int32, msg: UnsafePointer<CChar>?) {
 
-        let message: String = {
+        self.message = {
             guard let msg = msg, let message = String(validatingUTF8: msg) else {
                 return "Unknown gzip error"
             }
             return message
         }()
 
-        self = {
+        self.kind = {
             switch code {
             case Z_STREAM_ERROR:
-                return .stream(message: message)
-
+                return .stream
             case Z_DATA_ERROR:
-                return .data(message: message)
-
+                return .data
             case Z_MEM_ERROR:
-                return .memory(message: message)
-
+                return .memory
             case Z_BUF_ERROR:
-                return .buffer(message: message)
-
+                return .buffer
             case Z_VERSION_ERROR:
-                return .version(message: message)
-
+                return .version
             default:
-                return .unknown(message: message, code: Int(code))
+                return .unknown(code: Int(code))
             }
         }()
     }
 
 
     public var localizedDescription: String {
 
-        let description: String = {
-            switch self {
-            case .stream(let message):
-                return message
-            case .data(let message):
-                return message
-            case .memory(let message):
-                return message
-            case .buffer(let message):
-                return message
-            case .version(let message):
-                return message
-            case .unknown(let message, _):
-                return message
-            }
-        }()
-
-        return description
+        return self.message
     }
 
 }

Tests/GzipTests/GzipTests.swift

@@ -7,7 +7,7 @@
 /*
 The MIT License (MIT)
 
-© 2015-2016 1024jp
+© 2015-2017 1024jp
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
@@ -70,10 +70,10 @@ class GzipTests: XCTestCase {
         do {
             uncompressed = try data.gunzipped()
         } catch let error as GzipError {
-            switch error {
-            case .data(let message):
-                XCTAssertEqual(message, "incorrect header check")
-                XCTAssertEqual(message, error.localizedDescription)
+            switch error.kind {
+            case .data:
+                XCTAssertEqual(error.message, "incorrect header check")
+                XCTAssertEqual(error.message, error.localizedDescription)
             default:
                 XCTFail("Caught incorrect error.")
             }