match shell scripts by file extension

src/walk_scripts.rs

@@ -78,14 +78,24 @@ fn entry_is_file(entry: &ignore::DirEntry) -> bool {
 
 fn entry_is_shellscript(entry: &ignore::DirEntry) -> bool {
     if entry_is_file(entry) {
-        match file_format::FileFormat::from_file(entry.path()) {
-            Ok(fmt) => match fmt {
-                file_format::FileFormat::ShellScript => true,
-                _ => false,
+        match entry.path().extension() {
+            Some(ext) => match ext.to_str() {
+                Some("sh") | Some("bash") | Some("zsh") | Some("bats") => true,
+                Some(_) | None => entry_shellcript_format(entry),
             },
-            Err(err) => panic!("File Format Error: {}", err),
+            None => entry_shellcript_format(entry),
         }
     } else {
         false
     }
 }
+
+fn entry_shellcript_format(entry: &ignore::DirEntry) -> bool {
+    match file_format::FileFormat::from_file(entry.path()) {
+        Ok(fmt) => match fmt {
+            file_format::FileFormat::ShellScript => true,
+            _ => false,
+        },
+        Err(err) => panic!("File Format Error: {}", err),
+    }
+}

tests/cli.rs

@@ -36,3 +36,13 @@ fn compare_file(path: &str) {
 fn one_file() {
     compare_file("boringssl/crypto/lhash/make_macros.sh");
 }
+
+#[test]
+fn find_by_shebang() {
+    compare_file("pixelb-scripts/scripts/errno");
+}
+
+#[test]
+fn find_by_extension() {
+    compare_file("shell/shflags/shflags_issue_28_test.sh");
+}