[linter] Dot shorthands: Update exhaustive_cases lint.

Added support for the lint to fire on dot shorthand properties in switch cases.

Tests added and passing.

Bug: #60905, #60893
Change-Id: I475f79db547144817fecd4936616d959144b7404
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/434520
Reviewed-by: Brian Wilkerson <[email protected]>
Commit-Queue: Kallen Tu <[email protected]>

Author: kallentu

pkg/linter/lib/src/rules/exhaustive_cases.dart

@@ -68,6 +68,11 @@ class _Visitor extends SimpleAstVisitor<void> {
           if (variable is VariableElement) {
             enumConstants.remove(variable.computeConstantValue());
           }
+        } else if (expression is DotShorthandPropertyAccess) {
+          var variable = expression.propertyName.element.variableElement;
+          if (variable is VariableElement) {
+            enumConstants.remove(variable.computeConstantValue());
+          }
         }
         if (member is SwitchDefault) {
           return;

pkg/linter/test/rules/exhaustive_cases_test.dart

@@ -252,6 +252,102 @@ void s(Subclassed e) {
 
 @reflectiveTest
 class ExhaustiveCasesTest extends BaseExhaustiveCasesTest {
+  Future<void> test_dotShorthands_enumLike() async {
+    await assertDiagnostics(
+      r'''
+class E {
+  final int i;
+  const E._(this.i);
+
+  static const e = E._(1);
+  static const f = E._(2);
+  static const g = E._(3);
+}
+
+void fn(E e) {
+  switch (e) {
+    case .e:
+      break;
+    case .f:
+  }
+}
+''',
+      [lint(148, 10)],
+    );
+  }
+
+  Future<void> test_dotShorthands_enumLike_default_ok() async {
+    await assertNoDiagnostics(r'''
+class E {
+  final int i;
+  const E._(this.i);
+
+  static const e = E._(1);
+  static const f = E._(2);
+  static const g = E._(3);
+}
+
+void fn(E e) {
+  switch (e) {
+    case .e:
+      break;
+    default:
+      break;
+  }
+}
+''');
+  }
+
+  Future<void> test_dotShorthands_notEnumLike_ok() async {
+    await assertNoDiagnostics(r'''
+class TooFew {
+  const TooFew._();
+
+  static const e = TooFew._();
+}
+
+void t(TooFew e) {
+  switch (e) {
+    case TooFew.e:
+  }
+}
+
+class PublicCons {
+  const PublicCons();
+  static const e = PublicCons();
+  static const f = PublicCons();
+}
+
+void p(PublicCons e) {
+  switch (e) {
+    case .e:
+  }
+}
+''');
+  }
+
+  Future<void> test_dotShorthands_notEnumLike_subclassed_ok() async {
+    await assertNoDiagnostics(r'''
+class Subclassed {
+  const Subclassed._();
+
+  static const e = Subclassed._();
+  static const f = Subclassed._();
+  static const g = Subclassed._();
+}
+
+class Subclass extends Subclassed {
+  Subclass() : super._();
+}
+
+void s(Subclassed e) {
+  switch (e) {
+    case .e:
+  }
+}
+''');
+  }
+
   test_enum_ok() async {
     await assertDiagnostics(actualEnumSource, [
       error(CompileTimeErrorCode.NON_EXHAUSTIVE_SWITCH_STATEMENT, 52, 6),