extension type support for non_constant_identifier_names (#4696)

Author: pq

lib/src/rules/non_constant_identifier_names.dart

@@ -56,6 +56,7 @@ class NonConstantIdentifierNames extends LintRule {
     registry.addCatchClause(this, visitor);
     registry.addConstructorDeclaration(this, visitor);
     registry.addDeclaredVariablePattern(this, visitor);
+    registry.addExtensionTypeDeclaration(this, visitor);
     registry.addForEachPartsWithDeclaration(this, visitor);
     registry.addFormalParameterList(this, visitor);
     registry.addFunctionDeclaration(this, visitor);
@@ -105,6 +106,11 @@ class _Visitor extends SimpleAstVisitor<void> {
     checkIdentifier(node.name);
   }
 
+  @override
+  void visitExtensionTypeDeclaration(ExtensionTypeDeclaration node) {
+    checkIdentifier(node.representation.constructorName?.name);
+  }
+
   @override
   void visitForEachPartsWithDeclaration(ForEachPartsWithDeclaration node) {
     checkIdentifier(node.loopVariable.name);

test/rules/non_constant_identifier_names_test.dart

@@ -16,9 +16,20 @@ main() {
 
 @reflectiveTest
 class NonConstantIdentifierNamesPatternsTest extends LintRuleTest {
+  @override
+  List<String> get experiments => ['inline-class'];
+
   @override
   String get lintRule => 'non_constant_identifier_names';
 
+  test_extensionType_representationConstructorName() async {
+    await assertDiagnostics(r'''
+extension type e.Efg(int i) {}
+''', [
+      lint(17, 3),
+    ]);
+  }
+
   test_patternForStatement() async {
     await assertDiagnostics(r'''
 void f() {