[analyzer] add a quick fix for the prefer_relative_imports lint

Change-Id: Ic69ebe799f425fd09e002b65d66a4382f5f96ead
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/120160
Commit-Queue: Devon Carew <devoncarew@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Reviewed-by: Phil Quitslund <pquitslund@google.com>

Author: devoncarew

pkg/analysis_server/lib/src/services/correction/base_processor.dart

@@ -24,6 +24,7 @@ import 'package:analyzer_plugin/utilities/change_builder/change_builder_dart.dar
 import 'package:analyzer_plugin/utilities/change_builder/change_workspace.dart';
 import 'package:analyzer_plugin/utilities/range_factory.dart';
 import 'package:meta/meta.dart';
+import 'package:path/path.dart' as path;
 
 /// Base class for common processor functionality.
 abstract class BaseProcessor {
@@ -963,6 +964,65 @@ abstract class BaseProcessor {
     return null;
   }
 
+  Future<ChangeBuilder> createBuilder_convertToRelativeImport() async {
+    var node = this.node;
+    if (node is StringLiteral) {
+      node = node.parent;
+    }
+    if (node is! ImportDirective) {
+      return null;
+    }
+
+    ImportDirective importDirective = node;
+
+    // Ignore if invalid URI.
+    if (importDirective.uriSource == null) {
+      return null;
+    }
+
+    // Ignore if the uri is not a package: uri.
+    Uri sourceUri = resolvedResult.uri;
+    if (sourceUri.scheme != 'package') {
+      return null;
+    }
+
+    Uri importUri;
+    try {
+      importUri = Uri.parse(importDirective.uriContent);
+    } on FormatException {
+      return null;
+    }
+
+    // Ignore if import uri is not a package: uri.
+    if (importUri.scheme != 'package') {
+      return null;
+    }
+
+    // Verify that the source's uri and the import uri have the same package
+    // name.
+    List<String> sourceSegments = sourceUri.pathSegments;
+    List<String> importSegments = importUri.pathSegments;
+    if (sourceSegments.isEmpty ||
+        importSegments.isEmpty ||
+        sourceSegments.first != importSegments.first) {
+      return null;
+    }
+
+    final String relativePath = path.relative(
+      importUri.path,
+      from: path.dirname(sourceUri.path),
+    );
+
+    DartChangeBuilder changeBuilder = _newDartChangeBuilder();
+    await changeBuilder.addFileEdit(file, (builder) {
+      builder.addSimpleReplacement(
+        range.node(importDirective.uri).getExpanded(-1),
+        relativePath,
+      );
+    });
+    return changeBuilder;
+  }
+
   Future<ChangeBuilder> createBuilder_inlineAdd() async {
     AstNode node = this.node;
     if (node is! SimpleIdentifier || node.parent is! MethodInvocation) {

pkg/analysis_server/lib/src/services/correction/fix.dart

@@ -205,6 +205,8 @@ class DartFixKind {
       const FixKind('CONVERT_TO_NULL_AWARE', 50, "Convert to use '?.'");
   static const CONVERT_TO_PACKAGE_IMPORT = const FixKind(
       'CONVERT_TO_PACKAGE_IMPORT', 50, "Convert to 'package:' import");
+  static const CONVERT_TO_RELATIVE_IMPORT = const FixKind(
+      'CONVERT_TO_RELATIVE_IMPORT', 50, "Convert to relative import");
   static const CONVERT_TO_SINGLE_QUOTED_STRING = const FixKind(
       'CONVERT_TO_SINGLE_QUOTED_STRING', 50, "Convert to single quoted string");
   static const CONVERT_TO_SPREAD =

pkg/analysis_server/lib/src/services/correction/fix_internal.dart

@@ -693,6 +693,9 @@ class FixProcessor extends BaseProcessor {
       if (name == LintNames.prefer_null_aware_operators) {
         await _addFix_convertToNullAware();
       }
+      if (name == LintNames.prefer_relative_imports) {
+        await _addFix_convertToRelativeImport();
+      }
       if (name == LintNames.prefer_single_quotes) {
         await _addFix_convertSingleQuotes();
       }
@@ -1528,6 +1531,11 @@ class FixProcessor extends BaseProcessor {
     _addFixFromBuilder(changeBuilder, DartFixKind.CONVERT_TO_PACKAGE_IMPORT);
   }
 
+  Future<void> _addFix_convertToRelativeImport() async {
+    final changeBuilder = await createBuilder_convertToRelativeImport();
+    _addFixFromBuilder(changeBuilder, DartFixKind.CONVERT_TO_RELATIVE_IMPORT);
+  }
+
   Future<void> _addFix_createClass() async {
     Element prefixElement = null;
     String name = null;

pkg/analysis_server/lib/src/services/linter/lint_names.dart

@@ -50,6 +50,7 @@ class LintNames {
   static const String prefer_is_not_empty = 'prefer_is_not_empty';
   static const String prefer_null_aware_operators =
       'prefer_null_aware_operators';
+  static const String prefer_relative_imports = 'prefer_relative_imports';
   static const String prefer_single_quotes = 'prefer_single_quotes';
   static const String prefer_spread_collections = 'prefer_spread_collections';
   static const String slash_for_doc_comments = 'slash_for_doc_comments';

pkg/analysis_server/test/src/services/correction/fix/convert_to_relative_import_test.dart

@@ -0,0 +1,96 @@
+// Copyright (c) 2019, 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:analysis_server/src/services/correction/fix.dart';
+import 'package:analysis_server/src/services/linter/lint_names.dart';
+import 'package:analyzer_plugin/utilities/fixes/fixes.dart';
+import 'package:test_reflective_loader/test_reflective_loader.dart';
+
+import 'fix_processor.dart';
+
+main() {
+  defineReflectiveSuite(() {
+    defineReflectiveTests(ConvertToRelativeImportTest);
+  });
+}
+
+@reflectiveTest
+class ConvertToRelativeImportTest extends FixProcessorLintTest {
+  @override
+  FixKind get kind => DartFixKind.CONVERT_TO_RELATIVE_IMPORT;
+
+  @override
+  String get lintCode => LintNames.prefer_relative_imports;
+
+  test_relativeImport() async {
+    addSource('/home/test/lib/foo.dart', '');
+    testFile = convertPath('/home/test/lib/src/test.dart');
+    await resolveTestUnit('''
+import /*LINT*/'package:test/foo.dart';
+''');
+
+    await assertHasFix('''
+import /*LINT*/'../foo.dart';
+''');
+  }
+
+  test_relativeImportSameDirectory() async {
+    addSource('/home/test/lib/foo.dart', '');
+    testFile = convertPath('/home/test/lib/bar.dart');
+    await resolveTestUnit('''
+import /*LINT*/'package:test/foo.dart';
+''');
+
+    await assertHasFix('''
+import /*LINT*/'foo.dart';
+''');
+  }
+
+  test_relativeImportSubDirectory() async {
+    addSource('/home/test/lib/baz/foo.dart', '');
+    testFile = convertPath('/home/test/lib/test.dart');
+    await resolveTestUnit('''
+import /*LINT*/'package:test/baz/foo.dart';
+''');
+
+    await assertHasFix('''
+import /*LINT*/'baz/foo.dart';
+''');
+  }
+
+  test_relativeImportRespectQuoteStyle() async {
+    addSource('/home/test/lib/foo.dart', '');
+    testFile = convertPath('/home/test/lib/bar.dart');
+    await resolveTestUnit('''
+import /*LINT*/"package:test/foo.dart";
+''');
+
+    await assertHasFix('''
+import /*LINT*/"foo.dart";
+''');
+  }
+
+  test_relativeImportGarbledUri() async {
+    addSource('/home/test/lib/foo.dart', '');
+    testFile = convertPath('/home/test/lib/bar.dart');
+    await resolveTestUnit('''
+import /*LINT*/'package:test/foo';
+''');
+
+    await assertHasFix('''
+import /*LINT*/'foo';
+''');
+  }
+
+  // Validate we don't get a fix with imports referencing different packages.
+  test_relativeImportDifferentPackages() async {
+    addSource('/home/test1/lib/foo.dart', '');
+    testFile = convertPath('/home/test2/lib/bar.dart');
+    await resolveTestUnit('''
+import /*LINT*/'package:test1/foo.dart';
+''');
+
+    await assertNoFix();
+  }
+}

pkg/analysis_server/test/src/services/correction/fix/test_all.dart

@@ -46,6 +46,7 @@ import 'convert_to_int_literal_test.dart' as convert_to_int_literal;
 import 'convert_to_named_arguments_test.dart' as convert_to_named_arguments;
 import 'convert_to_null_aware_test.dart' as convert_to_null_aware;
 import 'convert_to_package_import_test.dart' as convert_to_package_import;
+import 'convert_to_relative_import_test.dart' as convert_to_relative_import;
 import 'convert_to_single_quoted_string_test.dart'
     as convert_to_single_quoted_string;
 import 'convert_to_spread_test.dart' as convert_to_spread;
@@ -172,6 +173,7 @@ main() {
     convert_to_named_arguments.main();
     convert_to_null_aware.main();
     convert_to_package_import.main();
+    convert_to_relative_import.main();
     convert_to_single_quoted_string.main();
     convert_to_spread.main();
     create_class.main();

pkg/analyzer/lib/dart/ast/ast.dart

@@ -1234,7 +1234,7 @@ abstract class CompilationUnit implements AstNode {
   /// directive in a comment at the top of the file.
   ///
   /// Might be `null` if, for example, this [CompilationUnit] has been
-  /// resynthesized from a summary,
+  /// resynthesized from a summary.
   FeatureSet get featureSet;
 
   /// Return the line information for this compilation unit.