Several tests for AnalysisDriver and an elements.dart tweak.

pkg/analyzer/test/src/dart/analysis/driver_test.dart

+// Copyright (c) 2016, 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.
+
+library analyzer.test.driver;
+
+import 'dart:async';
+import 'dart:convert';
+
+import 'package:analyzer/dart/ast/ast.dart';
+import 'package:analyzer/error/error.dart';
+import 'package:analyzer/file_system/file_system.dart';
+import 'package:analyzer/file_system/memory_file_system.dart';
+import 'package:analyzer/source/package_map_resolver.dart';
+import 'package:analyzer/src/dart/analysis/byte_store.dart';
+import 'package:analyzer/src/dart/analysis/driver.dart';
+import 'package:analyzer/src/error/codes.dart';
+import 'package:analyzer/src/generated/engine.dart' show AnalysisOptionsImpl;
+import 'package:analyzer/src/generated/source.dart';
+import 'package:async/async.dart';
+import 'package:convert/convert.dart';
+import 'package:crypto/crypto.dart';
+import 'package:test/test.dart';
+import 'package:test_reflective_loader/test_reflective_loader.dart';
+
+import '../../context/mock_sdk.dart';
+
+main() {
+  defineReflectiveSuite(() {
+    defineReflectiveTests(DriverTest);
+  });
+}
+
+@reflectiveTest
+class DriverTest {
+  static final MockSdk sdk = new MockSdk();
+
+  final MemoryResourceProvider provider = new MemoryResourceProvider();
+  final ByteStore byteStore = new _TestByteStore();
+  final ContentCache contentCache = new ContentCache();
+  final StringBuffer logBuffer = new StringBuffer();
+
+  AnalysisDriver driver;
+  StreamSplitter<AnalysisStatus> statusSplitter;
+  final List<AnalysisStatus> allStatuses = <AnalysisStatus>[];
+  final List<AnalysisResult> allResults = <AnalysisResult>[];
+
+  String _testProject;

[Brian Wilkerson, 2016/10/27 05:06:04]

Is there any value in these fields being private? The code would be easier to
read without all the underscores.

[scheglov, 2016/10/27 16:24:23]

Done.

+  String _testFile;
+
+  void setUp() {
+    new MockSdk();
+    _testProject = _p('/test/lib');
+    _testFile = _p('/test/lib/test.dart');
+    driver = new AnalysisDriver(
+        new PerformanceLog(logBuffer),
+        provider,
+        byteStore,
+        contentCache,
+        new SourceFactory([
+          new DartUriResolver(sdk),
+          new PackageMapUriResolver(provider, <String, List<Folder>>{
+            'test': [provider.getFolder(_testProject)]
+          })
+        ], null, provider),
+        new AnalysisOptionsImpl()..strongMode = true);
+    statusSplitter = new StreamSplitter(driver.status);
+    statusSplitter.split().listen(allStatuses.add);
+    driver.results.listen(allResults.add);
+  }
+
+  test_getResult() async {
+    String content = 'int f() => 42;';
+    provider.newFile(_testFile, content);
+    driver.addFile(_testFile);
+    driver.priorityFiles = [_testFile];

[Brian Wilkerson, 2016/10/27 05:06:04]

These four lines (or sometimes just the first three) get repeated frequently.
Consider a utility method, such as

addFile(String content, {bool priority: false})

[scheglov, 2016/10/27 16:24:23]

Done.

+
+    AnalysisResult result = await driver.getResult(_testFile);
+    expect(result.path, _testFile);
+    expect(result.uri.toString(), 'package:test/test.dart');
+    expect(result.content, content);
+    expect(result.contentHash, _md5(content));
+    expect(result.unit, isNotNull);
+    expect(result.errors, hasLength(0));
+
+    var f = result.unit.declarations[0] as FunctionDeclaration;
+    expect(f.name.staticType.toString(), '() → int');
+    expect(f.returnType.type.toString(), 'int');
+
+    // The same result is also received through the stream.
+    await _waitForIdle();
+    expect(allResults, [result]);
+  }
+
+  test_getResult_errors() async {
+    String content = 'main() { int vv; }';
+    provider.newFile(_testFile, content);
+    driver.addFile(_testFile);
+    driver.priorityFiles = [_testFile];
+
+    AnalysisResult result = await driver.getResult(_testFile);
+    expect(result.path, _testFile);
+    expect(result.errors, hasLength(1));
+    {
+      AnalysisError error = result.errors[0];
+      expect(error.offset, 13);
+      expect(error.length, 2);
+      expect(error.errorCode, HintCode.UNUSED_LOCAL_VARIABLE);
+      expect(error.message, "The value of the local variable 'vv' isn't used.");
+      expect(error.correction, "Try removing the variable, or using it.");
+    }
+  }
+
+  test_results_priority() async {
+    String content = 'int f() => 42;';
+    provider.newFile(_testFile, content);
+    driver.addFile(_testFile);
+    driver.priorityFiles = [_testFile];
+
+    await _waitForIdle();
+
+    expect(allResults, hasLength(1));
+    AnalysisResult result = allResults.single;
+    expect(result.path, _testFile);
+    expect(result.uri.toString(), 'package:test/test.dart');
+    expect(result.content, content);
+    expect(result.contentHash, _md5(content));
+    expect(result.unit, isNotNull);
+    expect(result.errors, hasLength(0));
+
+    var f = result.unit.declarations[0] as FunctionDeclaration;
+    expect(f.name.staticType.toString(), '() → int');
+    expect(f.returnType.type.toString(), 'int');
+  }
+
+  test_results_priorityFirst() async {
+    var a = _p('/test/lib/a.dart');
+    var b = _p('/test/lib/b.dart');
+    var c = _p('/test/lib/c.dart');
+    provider.newFile(a, 'class A {}');
+    provider.newFile(b, 'class B {}');
+    provider.newFile(c, 'class C {}');
+
+    driver.addFile(a);
+    driver.addFile(b);
+    driver.addFile(c);
+    driver.priorityFiles = [b];
+    await _waitForIdle();
+
+    expect(allResults, hasLength(3));
+    AnalysisResult result = allResults[0];
+    expect(result.path, b);
+    expect(result.unit, isNotNull);
+    expect(result.errors, hasLength(0));
+  }
+
+  test_results_regular() async {
+    String content = 'int f() => 42;';
+    provider.newFile(_testFile, content);
+    driver.addFile(_testFile);
+
+    await _waitForIdle();
+
+    expect(allResults, hasLength(1));
+    AnalysisResult result = allResults.single;
+    expect(result.path, _testFile);
+    expect(result.uri.toString(), 'package:test/test.dart');
+    expect(result.content, isNull);
+    expect(result.contentHash, _md5(content));
+    expect(result.unit, isNull);
+    expect(result.errors, hasLength(0));
+  }
+
+  test_results_status() async {
+    String content = 'int f() => 42;';
+    provider.newFile(_testFile, content);
+    driver.addFile(_testFile);
+
+    await _waitForIdle();
+
+    expect(allStatuses, hasLength(2));
+    expect(allStatuses[0].isAnalyzing, isTrue);
+    expect(allStatuses[0].isIdle, isFalse);
+    expect(allStatuses[1].isAnalyzing, isFalse);
+    expect(allStatuses[1].isIdle, isTrue);
+  }
+
+  /**
+   * Return the [provider] specific path for the given Posix [path].
+   */
+  String _p(String path) => provider.convertPath(path);
+
+  Future<Null> _waitForIdle() async {
+    await statusSplitter.split().firstWhere((status) => status.isIdle);
+  }
+
+  static String _md5(String content) {
+    return hex.encode(md5.convert(UTF8.encode(content)).bytes);
+  }
+}
+
+class _TestByteStore implements ByteStore {
+  final map = <String, List<int>>{};
+
+  @override
+  List<int> get(String key) {
+    return map[key];
+  }
+
+  @override
+  void put(String key, List<int> bytes) {
+    map[key] = bytes;
+  }
+}