Augment. Issue 55324. Recover from missing ';' in 'import augment'.

Bug: #55324
Change-Id: I7365a45718455d69985a968c683bcf6dd74f9505
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/360504
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>

pkg/analyzer/lib/src/fasta/ast_builder.dart

@@ -5251,34 +5251,47 @@ class AstBuilder extends StackListener {
     var prefix = pop(NullValues.Prefix) as SimpleIdentifierImpl?;
     var configurations = pop() as List<ConfigurationImpl>?;
 
-    final directive = directives.last as ImportDirectiveImpl;
-
-    // TODO(scheglov): This code would be easier if we used one object.
-    var mergedAsKeyword = directive.asKeyword;
-    var mergedPrefix = directive.prefix;
-    if (directive.asKeyword == null && asKeyword != null) {
-      mergedAsKeyword = asKeyword;
-      mergedPrefix = prefix;
-    }
-
-    directives.last = ImportDirectiveImpl(
-      comment: directive.documentationComment,
-      metadata: directive.metadata,
-      importKeyword: directive.importKeyword,
-      uri: directive.uri,
-      configurations: [
-        ...directive.configurations,
-        ...?configurations,
-      ],
-      deferredKeyword: directive.deferredKeyword ?? deferredKeyword,
-      asKeyword: mergedAsKeyword,
-      prefix: mergedPrefix,
-      combinators: [
-        ...directive.combinators,
-        ...?combinators,
-      ],
-      semicolon: semicolon ?? directive.semicolon,
-    );
+    final directive = directives.last;
+    switch (directive) {
+      case AugmentationImportDirectiveImpl():
+        directives.last = AugmentationImportDirectiveImpl(
+          comment: directive.documentationComment,
+          metadata: directive.metadata,
+          importKeyword: directive.importKeyword,
+          augmentKeyword: directive.augmentKeyword,
+          uri: directive.uri,
+          semicolon: semicolon ?? directive.semicolon,
+        );
+      case ImportDirectiveImpl():
+        // TODO(scheglov): This code would be easier if we used one object.
+        var mergedAsKeyword = directive.asKeyword;
+        var mergedPrefix = directive.prefix;
+        if (directive.asKeyword == null && asKeyword != null) {
+          mergedAsKeyword = asKeyword;
+          mergedPrefix = prefix;
+        }
+
+        directives.last = ImportDirectiveImpl(
+          comment: directive.documentationComment,
+          metadata: directive.metadata,
+          importKeyword: directive.importKeyword,
+          uri: directive.uri,
+          configurations: [
+            ...directive.configurations,
+            ...?configurations,
+          ],
+          deferredKeyword: directive.deferredKeyword ?? deferredKeyword,
+          asKeyword: mergedAsKeyword,
+          prefix: mergedPrefix,
+          combinators: [
+            ...directive.combinators,
+            ...?combinators,
+          ],
+          semicolon: semicolon ?? directive.semicolon,
+        );
+      default:
+        throw UnimplementedError('${directive.runtimeType}');
+    }
   }
 
   @override

pkg/analyzer/lib/src/test_utilities/find_node.dart

@@ -36,6 +36,9 @@ class FindNode {
 
   AssignmentExpression get singleAssignmentExpression => _single();
 
+  AugmentationImportDirective get singleAugmentationImportDirective =>
+      _single();
+
   AwaitExpression get singleAwaitExpression => _single();
 
   BinaryExpression get singleBinaryExpression => _single();

pkg/analyzer/test/src/dart/parser/augmentation_import_directive_test.dart

@@ -0,0 +1,92 @@
+// Copyright (c) 2024, the Dart project authors. Please see the AUTHORS file
+// 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/dart/error/syntactic_errors.dart';
+import 'package:test_reflective_loader/test_reflective_loader.dart';
+
+import '../../diagnostics/parser_diagnostics.dart';
+
+main() {
+  defineReflectiveSuite(() {
+    defineReflectiveTests(AugmentationImportDirectiveParserTest);
+  });
+}
+
+@reflectiveTest
+class AugmentationImportDirectiveParserTest extends ParserDiagnosticsTest {
+  test_it() {
+    final parseResult = parseStringWithErrors(r'''
+import augment 'a.dart';
+''');
+    parseResult.assertNoErrors();
+
+    final node = parseResult.findNode.singleAugmentationImportDirective;
+    assertParsedNodeText(node, r'''
+AugmentationImportDirective
+  importKeyword: import
+  augmentKeyword: augment
+  uri: SimpleStringLiteral
+    literal: 'a.dart'
+  semicolon: ;
+''');
+  }
+
+  test_noSemicolon() {
+    final parseResult = parseStringWithErrors(r'''
+import augment 'a.dart'
+''');
+    parseResult.assertErrors([
+      error(ParserErrorCode.EXPECTED_TOKEN, 15, 8),
+    ]);
+
+    final node = parseResult.findNode.singleAugmentationImportDirective;
+    assertParsedNodeText(node, r'''
+AugmentationImportDirective
+  importKeyword: import
+  augmentKeyword: augment
+  uri: SimpleStringLiteral
+    literal: 'a.dart'
+  semicolon: ; <synthetic>
+''');
+  }
+
+  test_noUri_hasSemicolon() {
+    final parseResult = parseStringWithErrors(r'''
+import augment ;
+''');
+    parseResult.assertErrors([
+      error(ParserErrorCode.EXPECTED_STRING_LITERAL, 15, 1),
+    ]);
+
+    final node = parseResult.findNode.singleAugmentationImportDirective;
+    assertParsedNodeText(node, r'''
+AugmentationImportDirective
+  importKeyword: import
+  augmentKeyword: augment
+  uri: SimpleStringLiteral
+    literal: "" <synthetic>
+  semicolon: ;
+''');
+  }
+
+  test_noUri_noSemicolon() {
+    final parseResult = parseStringWithErrors(r'''
+import augment
+''');
+    parseResult.assertErrors([
+      error(ParserErrorCode.EXPECTED_TOKEN, 7, 7),
+      error(ParserErrorCode.EXPECTED_STRING_LITERAL, 15, 0),
+    ]);
+
+    final node = parseResult.findNode.singleAugmentationImportDirective;
+    assertParsedNodeText(node, r'''
+AugmentationImportDirective
+  importKeyword: import
+  augmentKeyword: augment
+  uri: SimpleStringLiteral
+    literal: "" <synthetic>
+  semicolon: ; <synthetic>
+''');
+  }
+}

pkg/analyzer/test/src/dart/parser/import_directive_test.dart

@@ -0,0 +1,88 @@
+// Copyright (c) 2024, the Dart project authors. Please see the AUTHORS file
+// 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/dart/error/syntactic_errors.dart';
+import 'package:test_reflective_loader/test_reflective_loader.dart';
+
+import '../../diagnostics/parser_diagnostics.dart';
+
+main() {
+  defineReflectiveSuite(() {
+    defineReflectiveTests(ImportDirectiveParserTest);
+  });
+}
+
+@reflectiveTest
+class ImportDirectiveParserTest extends ParserDiagnosticsTest {
+  test_it() {
+    final parseResult = parseStringWithErrors(r'''
+import 'a.dart';
+''');
+    parseResult.assertNoErrors();
+
+    final node = parseResult.findNode.singleImportDirective;
+    assertParsedNodeText(node, r'''
+ImportDirective
+  importKeyword: import
+  uri: SimpleStringLiteral
+    literal: 'a.dart'
+  semicolon: ;
+''');
+  }
+
+  test_noSemicolon() {
+    final parseResult = parseStringWithErrors(r'''
+import 'a.dart'
+''');
+    parseResult.assertErrors([
+      error(ParserErrorCode.EXPECTED_TOKEN, 7, 8),
+    ]);
+
+    final node = parseResult.findNode.singleImportDirective;
+    assertParsedNodeText(node, r'''
+ImportDirective
+  importKeyword: import
+  uri: SimpleStringLiteral
+    literal: 'a.dart'
+  semicolon: ; <synthetic>
+''');
+  }
+
+  test_noUri_hasSemicolon() {
+    final parseResult = parseStringWithErrors(r'''
+import ;
+''');
+    parseResult.assertErrors([
+      error(ParserErrorCode.EXPECTED_STRING_LITERAL, 7, 1),
+    ]);
+
+    final node = parseResult.findNode.singleImportDirective;
+    assertParsedNodeText(node, r'''
+ImportDirective
+  importKeyword: import
+  uri: SimpleStringLiteral
+    literal: "" <synthetic>
+  semicolon: ;
+''');
+  }
+
+  test_noUri_noSemicolon() {
+    final parseResult = parseStringWithErrors(r'''
+import
+''');
+    parseResult.assertErrors([
+      error(ParserErrorCode.EXPECTED_TOKEN, 0, 6),
+      error(ParserErrorCode.EXPECTED_STRING_LITERAL, 7, 0),
+    ]);
+
+    final node = parseResult.findNode.singleImportDirective;
+    assertParsedNodeText(node, r'''
+ImportDirective
+  importKeyword: import
+  uri: SimpleStringLiteral
+    literal: "" <synthetic>
+  semicolon: ; <synthetic>
+''');
+  }
+}

pkg/analyzer/test/src/dart/parser/test_all.dart

@@ -4,10 +4,13 @@
 
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
+import 'augmentation_import_directive_test.dart'
+    as augmentation_import_directive;
 import 'class_test.dart' as class_;
 import 'doc_comment_test.dart' as doc_comment;
 import 'extension_test.dart' as extension_;
 import 'extension_type_test.dart' as extension_type;
+import 'import_directive_test.dart' as import_directive;
 import 'mixin_test.dart' as mixin_;
 import 'top_level_function_test.dart' as top_level_function;
 import 'top_level_variable_test.dart' as top_level_variable;
@@ -17,10 +20,12 @@ import 'variable_declaration_statement_test.dart'
 /// Utility for manually running all tests.
 main() {
   defineReflectiveSuite(() {
+    augmentation_import_directive.main();
     class_.main();
     doc_comment.main();
     extension_.main();
     extension_type.main();
+    import_directive.main();
     mixin_.main();
     top_level_function.main();
     top_level_variable.main();