[analyzer] Dot shorthands: Error - unable to resolve a dot shorthand property access.

Added `DOT_SHORTHAND_MISSING_CONTEXT` error code for when we don't find a valid context type to resolve the dot shorthand head with. `DOT_SHORTHAND_UNDEFINED_GETTER` is used for being unable to find a static getter or field with a certain context type and name.

Unit tests added and a few language error + co19 tests passing (eg `simple_identifier_extends_error_test`).

Bug: #59835
Change-Id: Ic515b57dd0f4243b049e02bd58b694a500d57975
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/425181
Reviewed-by: Brian Wilkerson <[email protected]>
Reviewed-by: Paul Berry <[email protected]>
Commit-Queue: Kallen Tu <[email protected]>

Author: kallentu

pkg/analysis_server/lib/src/services/correction/error_fix_status.yaml

@@ -514,6 +514,10 @@ CompileTimeErrorCode.DEFINITELY_UNASSIGNED_LATE_LOCAL_VARIABLE:
 CompileTimeErrorCode.DISALLOWED_TYPE_INSTANTIATION_EXPRESSION:
   status: needsFix
   since: 2.15
+CompileTimeErrorCode.DOT_SHORTHAND_MISSING_CONTEXT:
+  status: needsEvaluation
+CompileTimeErrorCode.DOT_SHORTHAND_UNDEFINED_GETTER:
+  status: needsEvaluation
 CompileTimeErrorCode.DUPLICATE_CONSTRUCTOR_DEFAULT:
   status: noFix
   notes: |-

pkg/analyzer/lib/src/dart/resolver/property_element_resolver.dart

@@ -42,10 +42,13 @@ class PropertyElementResolver with ScopeHelpers {
     DotShorthandPropertyAccessImpl node,
   ) {
     if (_resolver.isDotShorthandContextEmpty) {
-      // TODO(kallentu): Produce an error here for not being able to find a
-      // context type.
-      return PropertyElementResolverResult();
+      assert(
+        false,
+        'DotShorthandPropertyAccessImpl is not enclosed in an expression for '
+        'which DotShorthandMixin.isDotShorthand is true',
+      );
     }
+
     TypeImpl context =
         _resolver.getDotShorthandContext().unwrapTypeSchemaView();
 
@@ -61,26 +64,36 @@ class PropertyElementResolver with ScopeHelpers {
           identifier.name,
           _definingLibrary,
         );
-        if (element != null) {
-          return PropertyElementResolverResult(
-            readElementRequested2: element,
-            getType: element.returnType,
+        // We didn't resolve to any static getter or static field using the
+        // context type.
+        if (element == null) {
+          errorReporter.atNode(
+            node,
+            CompileTimeErrorCode.DOT_SHORTHAND_UNDEFINED_GETTER,
+            arguments: [node.propertyName.name, context.getDisplayString()],
           );
+          return PropertyElementResolverResult();
         }
-      } else {
-        var contextElement = context.element3;
-        return _resolveTargetInterfaceElement(
-          typeReference: contextElement,
-          isCascaded: false,
-          propertyName: identifier,
-          hasRead: true,
-          hasWrite: false,
+        return PropertyElementResolverResult(
+          readElementRequested2: element,
+          getType: element.returnType,
         );
       }
+      var contextElement = context.element3;
+      return _resolveTargetInterfaceElement(
+        typeReference: contextElement,
+        isCascaded: false,
+        propertyName: identifier,
+        hasRead: true,
+        hasWrite: false,
+        resolvingDotShorthand: true,
+      );
     }
 
-    // TODO(kallentu): Produce an error here for not being able to find a
-    // property.
+    errorReporter.atNode(
+      node,
+      CompileTimeErrorCode.DOT_SHORTHAND_MISSING_CONTEXT,
+    );
     return PropertyElementResolverResult();
   }
 
@@ -714,6 +727,7 @@ class PropertyElementResolver with ScopeHelpers {
     required SimpleIdentifier propertyName,
     required bool hasRead,
     required bool hasWrite,
+    bool resolvingDotShorthand = false,
   }) {
     if (isCascaded) {
       typeReference = _resolver.typeProvider.typeType.element3;
@@ -742,15 +756,25 @@ class PropertyElementResolver with ScopeHelpers {
           readElement = null;
         }
       } else {
-        var code =
-            typeReference is EnumElement
-                ? CompileTimeErrorCode.UNDEFINED_ENUM_CONSTANT
-                : CompileTimeErrorCode.UNDEFINED_GETTER;
-        errorReporter.atNode(
-          propertyName,
-          code,
-          arguments: [propertyName.name, typeReference.name3!],
-        );
+        if (resolvingDotShorthand) {
+          // We didn't resolve to any static getter or static field using the
+          // context type.
+          errorReporter.atNode(
+            propertyName,
+            CompileTimeErrorCode.DOT_SHORTHAND_UNDEFINED_GETTER,
+            arguments: [propertyName.name, typeReference.name3!],
+          );
+        } else {
+          var code =
+              typeReference is EnumElement
+                  ? CompileTimeErrorCode.UNDEFINED_ENUM_CONSTANT
+                  : CompileTimeErrorCode.UNDEFINED_GETTER;
+          errorReporter.atNode(
+            propertyName,
+            code,
+            arguments: [propertyName.name, typeReference.name3!],
+          );
+        }
       }
     }
 

pkg/analyzer/lib/src/error/codes.g.dart

@@ -1392,6 +1392,24 @@ class CompileTimeErrorCode extends ErrorCode {
     hasPublishedDocs: true,
   );
 
+  static const CompileTimeErrorCode DOT_SHORTHAND_MISSING_CONTEXT =
+      CompileTimeErrorCode(
+        'DOT_SHORTHAND_MISSING_CONTEXT',
+        "A dot shorthand can't be used where there is no context type.",
+      );
+
+  ///  Parameters:
+  ///  0: the name of the static getter
+  ///  1: the name of the enclosing type where the getter is being looked for
+  static const CompileTimeErrorCode
+  DOT_SHORTHAND_UNDEFINED_GETTER = CompileTimeErrorCode(
+    'DOT_SHORTHAND_UNDEFINED_GETTER',
+    "The static getter '{0}' isn't defined for the context type '{1}'.",
+    correctionMessage:
+        "Try correcting the name to the name of an existing static getter, or "
+        "defining a getter or field named '{0}'.",
+  );
+
   ///  No parameters.
   static const CompileTimeErrorCode DUPLICATE_CONSTRUCTOR_DEFAULT =
       CompileTimeErrorCode(

pkg/analyzer/lib/src/error/error_code_values.g.dart

@@ -174,6 +174,8 @@ const List<ErrorCode> errorCodeValues = [
   CompileTimeErrorCode.DEFERRED_IMPORT_OF_EXTENSION,
   CompileTimeErrorCode.DEFINITELY_UNASSIGNED_LATE_LOCAL_VARIABLE,
   CompileTimeErrorCode.DISALLOWED_TYPE_INSTANTIATION_EXPRESSION,
+  CompileTimeErrorCode.DOT_SHORTHAND_MISSING_CONTEXT,
+  CompileTimeErrorCode.DOT_SHORTHAND_UNDEFINED_GETTER,
   CompileTimeErrorCode.DUPLICATE_CONSTRUCTOR_DEFAULT,
   CompileTimeErrorCode.DUPLICATE_CONSTRUCTOR_NAME,
   CompileTimeErrorCode.DUPLICATE_DEFINITION,

pkg/analyzer/messages.yaml

@@ -3860,6 +3860,15 @@ CompileTimeErrorCode:
     comment: |-
       Parameters:
       0: the name of the duplicate entity
+  DOT_SHORTHAND_MISSING_CONTEXT:
+    problemMessage: "A dot shorthand can't be used where there is no context type."
+  DOT_SHORTHAND_UNDEFINED_GETTER:
+    problemMessage: "The static getter '{0}' isn't defined for the context type '{1}'."
+    correctionMessage: "Try correcting the name to the name of an existing static getter, or defining a getter or field named '{0}'."
+    comment: |-
+      Parameters:
+      0: the name of the static getter
+      1: the name of the enclosing type where the getter is being looked for
   DUPLICATE_CONSTRUCTOR_DEFAULT:
     sharedName: DUPLICATE_CONSTRUCTOR
     problemMessage: The unnamed constructor is already defined.

pkg/analyzer/test/src/dart/resolution/dot_shorthand_property_access_test.dart

@@ -2,6 +2,7 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+import 'package:analyzer/src/error/codes.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import 'context_collection_resolution.dart';
@@ -317,6 +318,62 @@ DotShorthandPropertyAccess
 ''');
   }
 
+  test_error_context_invalid() async {
+    await assertErrorsInCode(
+      '''
+class C { }
+
+void main() {
+  C Function() c = .member;
+  print(c);
+}
+''',
+      [error(CompileTimeErrorCode.DOT_SHORTHAND_MISSING_CONTEXT, 46, 7)],
+    );
+  }
+
+  test_error_context_none() async {
+    await assertErrorsInCode(
+      '''
+void main() {
+  var c = .member;
+  print(c);
+}
+''',
+      [error(CompileTimeErrorCode.DOT_SHORTHAND_MISSING_CONTEXT, 24, 7)],
+    );
+  }
+
+  test_error_unresolved() async {
+    await assertErrorsInCode(
+      '''
+class C { }
+
+void main() {
+  C c = .getter;
+  print(c);
+}
+''',
+      [error(CompileTimeErrorCode.DOT_SHORTHAND_UNDEFINED_GETTER, 36, 6)],
+    );
+  }
+
+  test_error_unresolved_new() async {
+    await assertErrorsInCode(
+      '''
+class C {
+  C.named();
+}
+
+void main() {
+  C c = .new;
+  print(c);
+}
+''',
+      [error(CompileTimeErrorCode.DOT_SHORTHAND_UNDEFINED_GETTER, 48, 4)],
+    );
+  }
+
   test_extensionType() async {
     await assertNoErrorsInCode('''
 extension type C(int integer) {

tests/language/dot_shorthands/simple/simple_identifier_error_test.dart

@@ -11,27 +11,33 @@ import '../dot_shorthand_helper.dart';
 
 void main() {
   var color = .blue;
-  //           ^^^^
-  // [analyzer] unspecified
+  //          ^^^^^
+  // [analyzer] COMPILE_TIME_ERROR.DOT_SHORTHAND_MISSING_CONTEXT
+  //           ^
   // [cfe] No type was provided to find the dot shorthand 'blue'.
 
   const constColor = .blue;
-  //                  ^^^^
-  // [analyzer] unspecified
+  //                 ^^^^^
+  // [analyzer] COMPILE_TIME_ERROR.CONST_INITIALIZED_WITH_NON_CONSTANT_VALUE
+  // [analyzer] COMPILE_TIME_ERROR.DOT_SHORTHAND_MISSING_CONTEXT
+  //                  ^
   // [cfe] No type was provided to find the dot shorthand 'blue'.
 
   var integer = .one;
-  //             ^^^
-  // [analyzer] unspecified
+  //            ^^^^
+  // [analyzer] COMPILE_TIME_ERROR.DOT_SHORTHAND_MISSING_CONTEXT
+  //             ^
   // [cfe] No type was provided to find the dot shorthand 'one'.
 
   const constInteger = .one;
-  //                    ^^^
-  // [analyzer] unspecified
+  //                   ^^^^
+  // [analyzer] COMPILE_TIME_ERROR.CONST_INITIALIZED_WITH_NON_CONSTANT_VALUE
+  // [analyzer] COMPILE_TIME_ERROR.DOT_SHORTHAND_MISSING_CONTEXT
+  //                    ^
   // [cfe] No type was provided to find the dot shorthand 'one'.
 
   Integer i = .one();
-  //          ^
-  // [analyzer] unspecified
+  //          ^^^^
+  // [analyzer] COMPILE_TIME_ERROR.INVOCATION_OF_NON_FUNCTION_EXPRESSION
   // [cfe] The method 'call' isn't defined for the class 'Integer'.
 }

tests/language/dot_shorthands/simple/simple_identifier_extends_error_test.dart

@@ -14,21 +14,24 @@ import '../dot_shorthand_helper.dart';
 
 void extendsInteger<X extends Integer>() {
   X x = .one;
-  //     ^^^
-  // [analyzer] unspecified
+  //    ^^^^
+  // [analyzer] COMPILE_TIME_ERROR.DOT_SHORTHAND_MISSING_CONTEXT
+  //     ^
   // [cfe] The static getter or field 'one' isn't defined for the type 'X'.
 }
 
 void extendsIntegerNullable<X extends Integer?>() {
   X x = .one;
-  //     ^^^
-  // [analyzer] unspecified
+  //    ^^^^
+  // [analyzer] COMPILE_TIME_ERROR.DOT_SHORTHAND_MISSING_CONTEXT
+  //     ^
   // [cfe] The static getter or field 'one' isn't defined for the type 'X'.
 }
 
 void extendsFutureOrInteger<X extends FutureOr<Integer>>() {
   X x = .one;
-  //     ^^^
-  // [analyzer] unspecified
+  //    ^^^^
+  // [analyzer] COMPILE_TIME_ERROR.DOT_SHORTHAND_MISSING_CONTEXT
+  //     ^
   // [cfe] The static getter or field 'one' isn't defined for the type 'X'.
 }

tests/language/explicit_type_instantiation_parsing_test.dart

@@ -249,6 +249,8 @@ void main() {
   // [cfe] A comparison expression can't be an operand of another comparison expression.
   //  ^
   // [analyzer] SYNTACTIC_ERROR.EXPERIMENT_NOT_ENABLED
+  //  ^^^^^^^^^
+  // [analyzer] COMPILE_TIME_ERROR.DOT_SHORTHAND_MISSING_CONTEXT
   // [cfe] This requires the experimental 'dot-shorthands' language feature to be enabled.
   //   ^
   // [cfe] The static getter or field 'instance' isn't defined for the type 'dynamic'.
@@ -259,6 +261,8 @@ void main() {
   // [cfe] A comparison expression can't be an operand of another comparison expression.
   //  ^
   // [analyzer] SYNTACTIC_ERROR.EXPERIMENT_NOT_ENABLED
+  //  ^^^^
+  // [analyzer] COMPILE_TIME_ERROR.DOT_SHORTHAND_MISSING_CONTEXT
   // [cfe] This requires the experimental 'dot-shorthands' language feature to be enabled.
   //   ^
   // [cfe] The static getter or field 'any' isn't defined for the type 'dynamic'.