feat: improve check unused l10n (#563)

* feat: improve check unused l10n

* chore: update changelog

* chore: fix linter

Author: incendial

CHANGELOG.md

@@ -8,6 +8,7 @@
 * chore: activate self implemented rules: `avoid-unnecessary-type-assertions`, `avoid-unnecessary-type-casts`, `prefer-first`, `prefer-last`, `prefer-match-file-name`
 * refactor: cleanup anti-patterns, metrics and rules documentation
 * fix: `no-magic-number` not working in array of widgets
+* feat: improve check unused l10n
 
 ## 4.6.0
 

lib/src/analyzers/unused_l10n_analyzer/unused_l10n_visitor.dart

@@ -18,17 +18,20 @@ class UnusedL10nVisitor extends RecursiveAstVisitor<void> {
     super.visitMethodInvocation(node);
 
     final target = node.target;
+    final name = node.methodName.name;
 
-    if (target is SimpleIdentifier && _classPattern.hasMatch(target.name)) {
-      final staticElement = target.staticElement;
-      final name = node.methodName.name;
+    if (_matchIdentifier(target)) {
+      _addMemberInvocation(target as SimpleIdentifier, name);
+    } else if (_matchConstructorOf(target)) {
+      _addMemberInvocationOnConstructor(
+        target as InstanceCreationExpression,
+        name,
+      );
+    } else if (_matchMethodOf(target)) {
+      final classTarget = (target as MethodInvocation).target;
 
-      if (staticElement is ClassElement) {
-        _invocations.update(
-          staticElement,
-          (value) => value..add(name),
-          ifAbsent: () => {name},
-        );
+      if (_matchIdentifier(classTarget)) {
+        _addMemberInvocation(classTarget as SimpleIdentifier, name);
       }
     }
   }
@@ -52,4 +55,66 @@ class UnusedL10nVisitor extends RecursiveAstVisitor<void> {
       }
     }
   }
+
+  @override
+  void visitPropertyAccess(PropertyAccess node) {
+    super.visitPropertyAccess(node);
+
+    final target = node.target;
+    final name = node.propertyName.name;
+
+    if (_matchConstructorOf(target)) {
+      _addMemberInvocationOnConstructor(
+        target as InstanceCreationExpression,
+        name,
+      );
+    } else if (_matchMethodOf(target)) {
+      final classTarget = (target as MethodInvocation).target;
+
+      if (_matchIdentifier(classTarget)) {
+        _addMemberInvocation(classTarget as SimpleIdentifier, name);
+      }
+    }
+  }
+
+  bool _matchIdentifier(Expression? target) =>
+      target is SimpleIdentifier && _classPattern.hasMatch(target.name);
+
+  bool _matchConstructorOf(Expression? target) =>
+      target is InstanceCreationExpression &&
+      _classPattern.hasMatch(
+        target.staticType?.getDisplayString(withNullability: false) ?? '',
+      ) &&
+      target.constructorName.name?.name == 'of';
+
+  bool _matchMethodOf(Expression? target) =>
+      target is MethodInvocation && target.methodName.name == 'of';
+
+  void _addMemberInvocation(SimpleIdentifier target, String name) {
+    final staticElement = target.staticElement;
+
+    if (staticElement is ClassElement) {
+      _invocations.update(
+        staticElement,
+        (value) => value..add(name),
+        ifAbsent: () => {name},
+      );
+    }
+  }
+
+  void _addMemberInvocationOnConstructor(
+    InstanceCreationExpression target,
+    String name,
+  ) {
+    final staticElement =
+        target.constructorName.staticElement?.enclosingElement;
+
+    if (staticElement is ClassElement) {
+      _invocations.update(
+        staticElement,
+        (value) => value..add(name),
+        ifAbsent: () => {name},
+      );
+    }
+  }
 }

test/resources/unused_l10n_analyzer/test_i18n.dart

@@ -7,6 +7,16 @@ class TestI18n {
 
   static String secondMethod(String value, num number) =>
       value + number.toString();
+
+  String regularMethod(String value) => value;
+
+  String get regularGetter => 'regular getter'; // LINT
+
+  final String regularField = 'regular field';
+
+  TestI18n.of(String value) {
+    print(value);
+  }
 }
 
 class S {
@@ -18,4 +28,17 @@ class S {
 
   static String secondMethod(String value, num number) => // LINT
       value + number.toString();
+
+  String regularMethod(String value) => value;
+
+  String get regularGetter => 'regular getter';
+
+  final String regularField = 'regular field'; // LINT
+
+  // ignore: prefer_constructors_over_static_methods
+  static S of(String value) {
+    print(value);
+
+    return S();
+  }
 }

test/resources/unused_l10n_analyzer/unused_l10n_analyzer_example.dart

@@ -4,8 +4,17 @@ void main() {
   final _ = TestI18n.method('value');
 
   S.getter;
+
+  TestI18n.of('').regularMethod('some-string');
+
+  TestI18n.of('').regularField.trim();
 }
 
 class SomeClass {
   final field = TestI18n.field;
+
+  void method() {
+    S.of('').regularMethod('');
+    S.of('').regularGetter;
+  }
 }

test/src/analyzers/unused_l10n_analyzer/unused_l10n_analyzer_test.dart

@@ -41,13 +41,18 @@ void main() {
         expect(firstIssue.location.line, 4);
         expect(firstIssue.location.column, 3);
 
-        final secondIssues = report.issues.last;
+        final secondIssue = report.issues.elementAt(1);
+        expect(secondIssue.memberName, 'regularGetter');
+        expect(secondIssue.location.line, 13);
+        expect(secondIssue.location.column, 3);
+
+        final thirdIssue = report.issues.elementAt(2);
         expect(
-          secondIssues.memberName,
+          thirdIssue.memberName,
           'secondMethod(String value, num number)',
         );
-        expect(secondIssues.location.line, 8);
-        expect(secondIssues.location.column, 3);
+        expect(thirdIssue.location.line, 8);
+        expect(thirdIssue.location.column, 3);
       });
 
       test('should analyze files with custom class pattern', () async {
@@ -67,24 +72,26 @@ void main() {
 
         final firstIssue = report.issues.first;
         expect(firstIssue.memberName, 'field');
-        expect(firstIssue.location.line, 13);
+        expect(firstIssue.location.line, 23);
         expect(firstIssue.location.column, 3);
 
-        final secondIssues = report.issues.elementAt(1);
-        expect(
-          secondIssues.memberName,
-          'method(String value)',
-        );
-        expect(secondIssues.location.line, 17);
-        expect(secondIssues.location.column, 3);
+        final secondIssue = report.issues.elementAt(1);
+        expect(secondIssue.memberName, 'regularField');
+        expect(secondIssue.location.line, 36);
+        expect(secondIssue.location.column, 3);
+
+        final thirdIssue = report.issues.elementAt(2);
+        expect(thirdIssue.memberName, 'method(String value)');
+        expect(thirdIssue.location.line, 27);
+        expect(thirdIssue.location.column, 3);
 
-        final thirdIssues = report.issues.elementAt(2);
+        final forthIssue = report.issues.elementAt(3);
         expect(
-          thirdIssues.memberName,
+          forthIssue.memberName,
           'secondMethod(String value, num number)',
         );
-        expect(thirdIssues.location.line, 19);
-        expect(thirdIssues.location.column, 3);
+        expect(forthIssue.location.line, 29);
+        expect(forthIssue.location.column, 3);
       });
 
       test('should report no issues for a custom class name pattern', () async {