Migrate some of the base test classes in server

Change-Id: I010389d51d519968ce7c1ecd8da8811d036d9ab2
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/193830
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Commit-Queue: Brian Wilkerson <brianwilkerson@google.com>

pkg/analysis_server/test/abstract_context.dart

@@ -2,8 +2,6 @@
 // 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.
 
-// @dart = 2.9
-
 import 'package:analyzer/dart/analysis/analysis_context.dart';
 import 'package:analyzer/dart/analysis/results.dart';
 import 'package:analyzer/dart/analysis/session.dart';
@@ -26,8 +24,8 @@ import 'package:meta/meta.dart';
 import 'src/utilities/mock_packages.dart';
 
 /// Finds an [Element] with the given [name].
-Element findChildElement(Element root, String name, [ElementKind kind]) {
-  Element result;
+Element? findChildElement(Element root, String name, [ElementKind? kind]) {
+  Element? result;
   root.accept(_ElementVisitorFunctionWrapper((Element element) {
     if (element.name != name) {
       return;
@@ -49,11 +47,11 @@ class AbstractContextTest with ResourceProviderMixin {
   final ByteStore _byteStore = MemoryByteStore();
 
   final Map<String, String> _declaredVariables = {};
-  AnalysisContextCollectionImpl _analysisContextCollection;
+  AnalysisContextCollectionImpl? _analysisContextCollection;
 
   List<AnalysisDriver> get allDrivers {
     _createAnalysisContexts();
-    return _analysisContextCollection.contexts.map((e) => e.driver).toList();
+    return _analysisContextCollection!.contexts.map((e) => e.driver).toList();
   }
 
   /// The file system specific `/home/test/analysis_options.yaml` path.
@@ -73,7 +71,7 @@ class AbstractContextTest with ResourceProviderMixin {
 
   AnalysisSession get session => contextFor('/home/test').currentSession;
 
-  String get testPackageLanguageVersion => '2.9';
+  String? get testPackageLanguageVersion => '2.9';
 
   String get testPackageLibPath => '$testPackageRootPath/lib';
 
@@ -107,9 +105,9 @@ class AbstractContextTest with ResourceProviderMixin {
 
   /// Create an analysis options file based on the given arguments.
   void createAnalysisOptionsFile({
-    List<String> experiments,
-    bool implicitCasts,
-    List<String> lints,
+    List<String>? experiments,
+    bool? implicitCasts,
+    List<String>? lints,
   }) {
     var buffer = StringBuffer();
 
@@ -147,16 +145,16 @@ class AbstractContextTest with ResourceProviderMixin {
   /// Return the existing analysis context that should be used to analyze the
   /// given [path], or throw [StateError] if the [path] is not analyzed in any
   /// of the created analysis contexts.
-  AnalysisContext getContext(String path) {
+  DriverBasedAnalysisContext getContext(String path) {
     path = convertPath(path);
-    return _analysisContextCollection.contextFor(path);
+    return _analysisContextCollection!.contextFor(path);
   }
 
   /// Return the existing analysis driver that should be used to analyze the
   /// given [path], or throw [StateError] if the [path] is not analyzed in any
   /// of the created analysis contexts.
   AnalysisDriver getDriver(String path) {
-    DriverBasedAnalysisContext context = getContext(path);
+    var context = getContext(path);
     return context.driver;
   }
 
@@ -210,8 +208,8 @@ class AbstractContextTest with ResourceProviderMixin {
   }
 
   void writeTestPackageConfig({
-    PackageConfigFileBuilder config,
-    String languageVersion,
+    PackageConfigFileBuilder? config,
+    String? languageVersion,
     bool flutter = false,
     bool meta = false,
     bool vector_math = false,
@@ -254,7 +252,7 @@ class AbstractContextTest with ResourceProviderMixin {
   }
 
   void _addAnalyzedFilesToDrivers() {
-    for (var analysisContext in _analysisContextCollection.contexts) {
+    for (var analysisContext in _analysisContextCollection!.contexts) {
       for (var path in analysisContext.contextRoot.analyzedFiles()) {
         if (file_paths.isDart(resourceProvider.pathContext, path)) {
           analysisContext.driver.addFile(path);
@@ -264,8 +262,9 @@ class AbstractContextTest with ResourceProviderMixin {
   }
 
   void _addAnalyzedFileToDrivers(String path) {
-    if (_analysisContextCollection != null) {
-      for (var analysisContext in _analysisContextCollection.contexts) {
+    var collection = _analysisContextCollection;
+    if (collection != null) {
+      for (var analysisContext in collection.contexts) {
         if (analysisContext.contextRoot.isAnalyzed(path)) {
           analysisContext.driver.addFile(path);
         }
@@ -277,7 +276,7 @@ class AbstractContextTest with ResourceProviderMixin {
     _createAnalysisContexts();
 
     path = convertPath(path);
-    return _analysisContextCollection.contextFor(path);
+    return _analysisContextCollection!.contextFor(path);
   }
 
   /// Create all analysis contexts in [collectionIncludedPaths].
@@ -302,7 +301,7 @@ class AbstractContextTest with ResourceProviderMixin {
 
 mixin WithNonFunctionTypeAliasesMixin on AbstractContextTest {
   @override
-  String get testPackageLanguageVersion => null;
+  String? get testPackageLanguageVersion => null;
 
   @override
   void setUp() {

pkg/analysis_server/test/abstract_single_unit.dart

@@ -2,8 +2,6 @@
 // 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.
 
-// @dart = 2.9
-
 import 'package:analyzer/dart/analysis/results.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
@@ -23,14 +21,14 @@ class AbstractSingleUnitTest extends AbstractContextTest {
   /// Whether to rewrite line endings in test code based on platform.
   bool useLineEndingsForPlatform = false;
 
-  String testCode;
-  String testFile;
-  ResolvedUnitResult testAnalysisResult;
-  CompilationUnit testUnit;
-  CompilationUnitElement testUnitElement;
-  LibraryElement testLibraryElement;
-  FindNode findNode;
-  FindElement findElement;
+  late String testCode;
+  late String testFile;
+  ResolvedUnitResult? testAnalysisResult;
+  late CompilationUnit testUnit;
+  late CompilationUnitElement testUnitElement;
+  late LibraryElement testLibraryElement;
+  late FindNode findNode;
+  late FindElement findElement;
 
   @override
   void addSource(String path, String content) {
@@ -72,11 +70,12 @@ class AbstractSingleUnitTest extends AbstractContextTest {
   }
 
   Future<void> resolveTestFile() async {
-    testAnalysisResult = await session.getResolvedUnit(testFile);
-    testCode = testAnalysisResult.content;
-    testUnit = testAnalysisResult.unit;
+    var result = await session.getResolvedUnit(testFile);
+    testAnalysisResult = result;
+    testCode = result.content!;
+    testUnit = result.unit!;
     if (verifyNoTestUnitErrors) {
-      expect(testAnalysisResult.errors.where((AnalysisError error) {
+      expect(result.errors.where((AnalysisError error) {
         return error.errorCode != HintCode.DEAD_CODE &&
             error.errorCode != HintCode.UNUSED_CATCH_CLAUSE &&
             error.errorCode != HintCode.UNUSED_CATCH_STACK &&
@@ -86,7 +85,7 @@ class AbstractSingleUnitTest extends AbstractContextTest {
             error.errorCode != HintCode.UNUSED_LOCAL_VARIABLE;
       }), isEmpty);
     }
-    testUnitElement = testUnit.declaredElement;
+    testUnitElement = testUnit.declaredElement!;
     testLibraryElement = testUnitElement.library;
     findNode = FindNode(testCode, testUnit);
     findElement = FindElement(testUnit);

pkg/analysis_server/test/src/utilities/mock_packages.dart

@@ -2,8 +2,6 @@
 // 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.
 
-// @dart = 2.9
-
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer/file_system/physical_file_system.dart';
@@ -59,13 +57,13 @@ class BazelMockPackages {
   Folder _addFiles(MemoryResourceProvider provider, String packageName) {
     var packagesPath = provider.convertPath('/workspace/third_party/dart');
 
-    for (var relativePosixPath in _cachedFiles.keys) {
+    for (var entry in _cachedFiles.entries) {
+      var relativePosixPath = entry.key;
       var relativePathComponents = relativePosixPath.split('/');
       if (relativePathComponents[0] == packageName) {
         var relativePath = provider.pathContext.joinAll(relativePathComponents);
         var path = provider.pathContext.join(packagesPath, relativePath);
-        var content = _cachedFiles[relativePosixPath];
-        provider.newFile(path, content);
+        provider.newFile(path, entry.value);
       }
     }
 
@@ -114,13 +112,13 @@ class MockPackages {
   Folder _addFiles(MemoryResourceProvider provider, String packageName) {
     var packagesPath = provider.convertPath('/packages');
 
-    for (var relativePosixPath in _cachedFiles.keys) {
+    for (var entry in _cachedFiles.entries) {
+      var relativePosixPath = entry.key;
       var relativePathComponents = relativePosixPath.split('/');
       if (relativePathComponents[0] == packageName) {
         var relativePath = provider.pathContext.joinAll(relativePathComponents);
         var path = provider.pathContext.join(packagesPath, relativePath);
-        var content = _cachedFiles[relativePosixPath];
-        provider.newFile(path, content);
+        provider.newFile(path, entry.value);
       }
     }