port DDC checker code to analyzer

pkg/analyzer/test/src/task/strong/strong_test_helper.dart

+// Copyright (c) 2015, 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.
+
+// TODO(jmesserly): this file needs to be refactored, it's a port from
+// package:dev_compiler's tests
+library test.src.task.strong.strong_test_helper;
+
+import 'package:analyzer/file_system/file_system.dart';
+import 'package:analyzer/file_system/memory_file_system.dart';
+import 'package:analyzer/src/context/context.dart' show SdkAnalysisContext;
+import 'package:analyzer/src/generated/ast.dart';
+import 'package:analyzer/src/generated/element.dart';
+import 'package:analyzer/src/generated/engine.dart' hide SdkAnalysisContext;
+import 'package:analyzer/src/generated/error.dart';
+import 'package:analyzer/src/generated/sdk.dart';
+import 'package:analyzer/src/generated/source.dart';
+import 'package:analyzer/src/task/strong/checker.dart';
+import 'package:analyzer/src/task/strong/rules.dart';
+import 'package:logging/logging.dart'; // TODO(jmesserly): remove
+import 'package:source_span/source_span.dart'; // TODO(jmesserly): remove
+import 'package:unittest/unittest.dart';
+
+
+/// Run the checker on a program with files contents as indicated in
+/// [testFiles].
+///
+/// This function makes several assumptions to make it easier to describe error
+/// expectations:
+///
+///   * a file named `/main.dart` exists in [testFiles].
+///   * all expected failures are listed in the source code using comments
+///   immediately in front of the AST node that should contain the error.
+///   * errors are formatted as a token `level:Type`, where `level` is the
+///   logging level were the error would be reported at, and `Type` is the
+///   concrete subclass of [StaticInfo] that denotes the error.
+///
+/// For example, to check that an assignment produces a warning about a boxing
+/// conversion, you can describe the test as follows:
+///
+///     testChecker({
+///       '/main.dart': '''
+///           testMethod() {
+///             dynamic x = /*warning:Box*/3;
+///           }
+///       '''
+///     });
+///
+void testChecker(String name, Map<String, String> testFiles) {
+  test(name, () {
+    expect(testFiles.containsKey('/main.dart'), isTrue,
+        reason: '`/main.dart` is missing in testFiles');
+
+    var provider = new MemoryResourceProvider();
+    testFiles.forEach((key, value) {
+      var scheme = 'package:';
+      if (key.startsWith(scheme)) {
+        key = '/packages/${key.substring(scheme.length)}';
+      }
+      provider.newFile(key, value);
+    });
+    var uriResolver = new TestUriResolver(provider);
+    // Enable task model strong mode
+    AnalysisEngine.instance.useTaskModel = true;
+    var context = AnalysisEngine.instance.createAnalysisContext();
+    context.analysisOptions.strongMode = true;
+
+    context.sourceFactory = new SourceFactory([
+      new MockDartSdk(mockSdkSources, reportMissing: true).resolver,
+      uriResolver
+    ]);
+
+    // Run the checker on /main.dart.
+    Source mainSource = uriResolver.resolveAbsolute(new Uri.file('/main.dart'));
+    var initialLibrary =
+        context.resolveCompilationUnit2(mainSource, mainSource);
+
+    var collector = new _ErrorCollector();
+    var errorReporter = new ErrorReporter(collector, mainSource);
+    var checker = new CodeChecker(new TypeRules(context.typeProvider),
+        errorReporter);
+
+    // Extract expectations from the comments in the test files, and
+    // check that all errors we emit are included in the expected map.
+    var allLibraries = reachableLibraries(initialLibrary.element.library);
+    for (var lib in allLibraries) {
+      for (var unit in lib.units) {
+        var errors = <AnalysisError>[];
+        collector.errors = errors;
+
+        var source = unit.source;
+        if (source.uri.scheme == 'dart') continue;
+        errorReporter.source = unit.source;
+
+        var librarySource = context.getLibrariesContaining(source).single;
+        var resolved = context.resolveCompilationUnit2(source, librarySource);
+        checker.visitCompilationUnit(resolved);
+
+        new _ExpectedErrorVisitor(errors).validate(resolved);
+      }
+    }
+  });
+}
+
+class _ErrorCollector implements AnalysisErrorListener {
+  List<AnalysisError> errors;
+  final bool hints;
+  _ErrorCollector({this.hints: true});
+
+  void onError(AnalysisError error) {
+    // Unless DDC hints are requested, filter them out.
+    var HINT = ErrorSeverity.INFO.ordinal;
+    if (hints || error.errorCode.errorSeverity.ordinal > HINT) {
+      errors.add(error);
+    }
+  }
+}
+
+class TestUriResolver extends ResourceUriResolver {
+  final MemoryResourceProvider provider;
+  TestUriResolver(provider)
+      : provider = provider,
+        super(provider);
+
+  @override
+  Source resolveAbsolute(Uri uri, [Uri actualUri]) {
+    if (uri.scheme == 'package') {
+      return (provider.getResource('/packages/' + uri.path) as File)
+          .createSource(uri);
+    }
+    return super.resolveAbsolute(uri, actualUri);
+  }
+}
+
+class _ExpectedErrorVisitor extends UnifyingAstVisitor {
+  final Set<AnalysisError> _actualErrors;
+  CompilationUnit _unit;
+  String _unitSourceCode;
+
+  _ExpectedErrorVisitor(List<AnalysisError> actualErrors)
+      : _actualErrors = new Set.from(actualErrors);
+
+  validate(CompilationUnit unit) {
+    _unit = unit;
+    // This reads the file. Only safe because tests use MemoryFileSystem.
+    _unitSourceCode = unit.element.source.contents.data;
+
+    // Visit the compilation unit.
+    unit.accept(this);
+
+    if (_actualErrors.isNotEmpty) {
+      var actualMsgs = _actualErrors.map(_formatActualError).join('\n');
+      fail('Unexpected errors reported by checker:\n\n$actualMsgs');
+    }
+  }
+
+  visitNode(AstNode node) {
+    var token = node.beginToken;
+    var comment = token.precedingComments;
+    // Use error marker found in an immediately preceding comment,
+    // and attach it to the outermost expression that starts at that token.
+    if (comment != null) {
+      while (comment.next != null) {
+        comment = comment.next;
+      }
+      if (comment.end == token.offset && node.parent.beginToken != token) {
+        var commentText = '$comment';
+        var start = commentText.lastIndexOf('/*');
+        var end = commentText.lastIndexOf('*/');
+        if (start != -1 && end != -1) {
+          expect(start, lessThan(end));
+          var errors = commentText.substring(start + 2, end).split(',');
+          var expectations =
+              errors.map(_ErrorExpectation.parse).where((x) => x != null);
+
+          for (var e in expectations) _expectError(node, e);
+        }
+      }
+    }
+    return super.visitNode(node);
+  }
+
+  void _expectError(AstNode node, _ErrorExpectation expected) {
+    // See if we can find the expected error in our actual errors
+    for (var actual in _actualErrors) {
+      if (actual.offset == node.offset && actual.length == node.length) {
+        var actualMsg = _formatActualError(actual);
+        expect(_actualErrorLevel(actual), expected.level,
+            reason: 'expected different error code at:\n\n$actualMsg');
+        expect(errorCodeName(actual.errorCode), expected.typeName,
+            reason: 'expected different error type at:\n\n$actualMsg');
+
+        // We found it. Stop the search.
+        _actualErrors.remove(actual);
+        return;
+      }
+    }
+
+    var span = _createSpan(node.offset, node.length);
+    var levelName = expected.level.name.toLowerCase();
+    var msg = span.message(expected.typeName, color: colorOf(levelName));
+    fail('expected error was not reported at:\n\n$levelName: $msg');
+  }
+
+  Level _actualErrorLevel(AnalysisError actual) {
+    return const <ErrorSeverity, Level>{
+      ErrorSeverity.ERROR: Level.SEVERE,
+      ErrorSeverity.WARNING: Level.WARNING,
+      ErrorSeverity.INFO: Level.INFO
+    }[actual.errorCode.errorSeverity];
+  }
+
+  String _formatActualError(AnalysisError actual) {
+    var span = _createSpan(actual.offset, actual.length);
+    var levelName = _actualErrorLevel(actual).name.toLowerCase();
+    var msg = span.message(actual.message, color: colorOf(levelName));
+    return '$levelName: [${errorCodeName(actual.errorCode)}] $msg';
+  }
+
+  SourceSpan _createSpan(int offset, int len) {
+    return createSpanHelper(_unit.lineInfo, offset, offset + len,
+        _unit.element.source, _unitSourceCode);
+  }
+}
+
+SourceLocation locationForOffset(LineInfo lineInfo, Uri uri, int offset) {
+  var loc = lineInfo.getLocation(offset);
+  return new SourceLocation(offset,
+      sourceUrl: uri, line: loc.lineNumber - 1, column: loc.columnNumber - 1);
+}
+
+SourceSpanWithContext createSpanHelper(
+    LineInfo lineInfo, int start, int end, Source source, String content) {
+  var startLoc = locationForOffset(lineInfo, source.uri, start);
+  var endLoc = locationForOffset(lineInfo, source.uri, end);
+
+  var lineStart = startLoc.offset - startLoc.column;
+  // Find the end of the line. This is not exposed directly on LineInfo, but
+  // we can find it pretty easily.
+  // TODO(jmesserly): for now we do the simple linear scan. Ideally we can get
+  // some help from the LineInfo API.
+  int lineEnd = endLoc.offset;
+  int lineNum = lineInfo.getLocation(lineEnd).lineNumber;
+  while (lineEnd < content.length &&
+      lineInfo.getLocation(++lineEnd).lineNumber == lineNum);
+
+  var text = content.substring(start, end);
+  var lineText = content.substring(lineStart, lineEnd);
+  return new SourceSpanWithContext(startLoc, endLoc, text, lineText);
+}
+
+/// Describes an expected message that should be produced by the checker.
+class _ErrorExpectation {
+  final Level level;
+  final String typeName;
+  _ErrorExpectation(this.level, this.typeName);
+
+  static _ErrorExpectation _parse(String descriptor) {
+    var tokens = descriptor.split(':');
+    expect(tokens.length, 2, reason: 'invalid error descriptor');
+    var name = tokens[0].toUpperCase();
+    var typeName = tokens[1];
+
+    var level =
+        Level.LEVELS.firstWhere((l) => l.name == name, orElse: () => null);
+    expect(level, isNotNull,
+        reason: 'invalid level in error descriptor: `${tokens[0]}`');
+    expect(typeName, isNotNull,
+        reason: 'invalid type in error descriptor: ${tokens[1]}');
+    return new _ErrorExpectation(level, typeName);
+  }
+
+  static _ErrorExpectation parse(String descriptor) {
+    descriptor = descriptor.trim();
+    var tokens = descriptor.split(' ');
+    if (tokens.length == 1) return _parse(tokens[0]);
+    expect(tokens.length, 4, reason: 'invalid error descriptor');
+    expect(tokens[1], "should", reason: 'invalid error descriptor');
+    expect(tokens[2], "be", reason: 'invalid error descriptor');
+    if (tokens[0] == "pass") return null;
+    // TODO(leafp) For now, we just use whatever the current expectation is,
+    // eventually we could do more automated reporting here.
+    return _parse(tokens[0]);
+  }
+
+  String toString() => '$level $typeName';
+}
+
+
+/// Dart SDK which contains a mock implementation of the SDK libraries. May be
+/// used to speed up execution when most of the core libraries is not needed.
+class MockDartSdk implements DartSdk {
+  final Map<Uri, _MockSdkSource> _sources = {};
+  final bool reportMissing;
+  final Map<String, SdkLibrary> _libs = {};
+  final String sdkVersion = '0';
+  List<String> get uris => _sources.keys.map((uri) => '$uri').toList();
+  final AnalysisContext context = new SdkAnalysisContext();
+  DartUriResolver _resolver;
+  DartUriResolver get resolver => _resolver;
+
+  MockDartSdk(Map<String, String> sources, {this.reportMissing}) {
+    sources.forEach((uriString, contents) {
+      var uri = Uri.parse(uriString);
+      _sources[uri] = new _MockSdkSource(uri, contents);
+      _libs[uriString] = new SdkLibraryImpl(uri.path)
+        ..setDart2JsLibrary()
+        ..setVmLibrary();
+    });
+    _resolver = new DartUriResolver(this);
+    context.sourceFactory = new SourceFactory([_resolver]);
+  }
+
+  List<SdkLibrary> get sdkLibraries => _libs.values.toList();
+  SdkLibrary getSdkLibrary(String dartUri) => _libs[dartUri];
+  Source mapDartUri(String dartUri) => _getSource(Uri.parse(dartUri));
+
+  Source fromEncoding(UriKind kind, Uri uri) {
+    if (kind != UriKind.DART_URI) {
+      throw new UnsupportedError('expected dart: uri kind, got $kind.');
+    }
+    return _getSource(uri);
+  }
+
+  Source _getSource(Uri uri) {
+    var src = _sources[uri];
+    if (src == null) {
+      if (reportMissing) print('warning: missing mock for $uri.');
+      _sources[uri] =
+          src = new _MockSdkSource(uri, 'library dart.${uri.path};');
+    }
+    return src;
+  }
+
+  @override
+  Source fromFileUri(Uri uri) {
+    throw new UnsupportedError('MockDartSdk.fromFileUri');
+  }
+}
+
+class _MockSdkSource implements Source {
+  /// Absolute URI which this source can be imported from.
+  final Uri uri;
+  final String _contents;
+
+  _MockSdkSource(this.uri, this._contents);
+
+  bool exists() => true;
+
+  int get hashCode => uri.hashCode;
+
+  final int modificationStamp = 1;
+
+  TimestampedData<String> get contents =>
+      new TimestampedData(modificationStamp, _contents);
+
+  String get encoding => "${uriKind.encoding}$uri";
+
+  Source get source => this;
+
+  String get fullName => shortName;
+
+  String get shortName => uri.path;
+
+  UriKind get uriKind => UriKind.DART_URI;
+
+  bool get isInSystemLibrary => true;
+
+  Source resolveRelative(Uri relativeUri) =>
+      throw new UnsupportedError('not expecting relative urls in dart: mocks');
+
+  Uri resolveRelativeUri(Uri relativeUri) =>
+      throw new UnsupportedError('not expecting relative urls in dart: mocks');
+}
+
+/// Sample mock SDK sources.
+final Map<String, String> mockSdkSources = {
+  // The list of types below is derived from:
+  //   * types we use via our smoke queries, including HtmlElement and
+  //     types from `_typeHandlers` (deserialize.dart)
+  //   * types that are used internally by the resolver (see
+  //   _initializeFrom in resolver.dart).
+  'dart:core': '''
+        library dart.core;
+
+        void print(Object o) {}
+
+        class Object {
+          int get hashCode {}
+          Type get runtimeType {}
+          String toString(){}
+          bool ==(other){}
+        }
+        class Function {}
+        class StackTrace {}
+        class Symbol {}
+        class Type {}
+
+        class String {
+          String operator +(String other) {}
+        }
+        class bool {}
+        class num {
+          num operator +(num other) {}
+        }
+        class int extends num {
+          bool operator<(num other) {}
+          int operator-() {}
+        }
+        class double extends num {}
+        class DateTime {}
+        class Null {}
+
+        class Deprecated {
+          final String expires;
+          const Deprecated(this.expires);
+        }
+        const Object deprecated = const Deprecated("next release");
+        class _Override { const _Override(); }
+        const Object override = const _Override();
+        class _Proxy { const _Proxy(); }
+        const Object proxy = const _Proxy();
+
+        class Iterable<E> {
+          fold(initialValue, combine(previousValue, E element)) {}
+          Iterable map(f(E element)) {}
+        }
+        class List<E> implements Iterable<E> {
+          List([int length]);
+          List.filled(int length, E fill);
+        }
+        class Map<K, V> {
+          Iterable<K> get keys {}
+        }
+        ''',
+  'dart:async': '''
+        class Future<T> {
+          Future(computation()) {}
+          Future.value(T t) {}
+          Future then(onValue(T value)) {}
+          static Future<List> wait(Iterable<Future> futures) {}
+        }
+        class Stream<T> {}
+  ''',
+  'dart:html': '''
+        library dart.html;
+        class HtmlElement {}
+        ''',
+  'dart:math': '''
+        library dart.math;
+        class Random {
+          bool nextBool() {}
+        }
+        num min(num x, num y) {}
+        num max(num x, num y) {}
+        ''',
+};
+
+
+/// Returns all libraries transitively imported or exported from [start].
+List<LibraryElement> reachableLibraries(LibraryElement start) {
+  var results = <LibraryElement>[];
+  var seen = new Set();
+  void find(LibraryElement lib) {
+    if (seen.contains(lib)) return;
+    seen.add(lib);
+    results.add(lib);
+    lib.importedLibraries.forEach(find);
+    lib.exportedLibraries.forEach(find);
+  }
+  find(start);
+  return results;
+}
+
+String errorCodeName(ErrorCode errorCode) {
+  var name = errorCode.name;
+  final prefix = 'dev_compiler.';
+  if (name.startsWith(prefix)) {
+    return name.substring(prefix.length);
+  } else {
+    // TODO(jmesserly): this is for backwards compat, but not sure it's very
+    // useful to log this.
+    return 'AnalyzerMessage';
+  }
+}
+
+/// Returns an ANSII color escape sequence corresponding to [levelName]. Colors
+/// are defined for: severe, error, warning, or info. Returns null if the level
+/// name is not recognized.
+String colorOf(String levelName) {
+  levelName = levelName.toLowerCase();
+  if (levelName == 'shout' || levelName == 'severe' || levelName == 'error') {
+    return _RED_COLOR;
+  }
+  if (levelName == 'warning') return _MAGENTA_COLOR;
+  if (levelName == 'info') return _CYAN_COLOR;
+  return null;
+}
+
+const String _RED_COLOR = '\u001b[31m';
+const String _MAGENTA_COLOR = '\u001b[35m';
+const String _CYAN_COLOR = '\u001b[36m';
+const String GREEN_COLOR = '\u001b[32m';
+const String NO_COLOR = '\u001b[0m';