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code_transformers/lib/src/resolver_impl.dart

Index: code_transformers/lib/src/resolver_impl.dart
diff --git a/code_transformers/lib/src/resolver_impl.dart b/code_transformers/lib/src/resolver_impl.dart
deleted file mode 100644
index 64e8196e6349cec87efdf8a07fd4350c8b03cdb7..0000000000000000000000000000000000000000
--- a/code_transformers/lib/src/resolver_impl.dart
+++ /dev/null
@@ -1,553 +0,0 @@
-// Copyright (c) 2014, 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 code_transformer.src.resolver_impl;
-
-import 'dart:async';
-import 'package:analyzer/analyzer.dart' show parseDirectives;
-import 'package:analyzer/src/generated/ast.dart' hide ConstantEvaluator;
-import 'package:analyzer/src/generated/constant.dart'
-    show ConstantEvaluator, EvaluationResult;
-import 'package:analyzer/src/generated/element.dart';
-import 'package:analyzer/src/generated/engine.dart';
-import 'package:analyzer/src/generated/sdk.dart' show DartSdk;
-import 'package:analyzer/src/generated/source.dart';
-import 'package:barback/barback.dart';
-import 'package:code_transformers/assets.dart';
-import 'package:path/path.dart' as native_path;
-import 'package:source_maps/refactor.dart';
-import 'package:source_span/source_span.dart';
-
-import 'resolver.dart';
-import 'dart_sdk.dart' show UriAnnotatedSource;
-
-// We should always be using url paths here since it's always Dart/pub code.
-final path = native_path.url;
-
-/// Resolves and updates an AST based on Barback-based assets.
-///
-/// This also provides a handful of useful APIs for traversing and working
-/// with the resolved AST.
-class ResolverImpl implements Resolver {
-  /// Cache of all asset sources currently referenced.
-  final Map<AssetId, _AssetBasedSource> sources = <AssetId, _AssetBasedSource>{
-  };
-
-  final InternalAnalysisContext _context =
-      AnalysisEngine.instance.createAnalysisContext();
-
-  /// Transform for which this is currently updating, or null when not updating.
-  Transform _currentTransform;
-
-  /// The currently resolved entry libraries, or null if nothing is resolved.
-  List<LibraryElement> _entryLibraries;
-  Set<LibraryElement> _libraries;
-
-  /// Future indicating when this resolver is done in the current phase.
-  Future _lastPhaseComplete = new Future.value();
-
-  /// Completer for wrapping up the current phase.
-  Completer _currentPhaseComplete;
-
-  /// Creates a resolver with a given [sdk] implementation for resolving
-  /// `dart:*` imports.
-  ResolverImpl(DartSdk sdk, DartUriResolver dartUriResolver,
-      {AnalysisOptions options}) {
-    if (options == null) {
-      options = new AnalysisOptionsImpl()
-        ..cacheSize = 256 // # of sources to cache ASTs for.
-        ..preserveComments = false
-        ..analyzeFunctionBodies = true;
-    }
-    _context.analysisOptions = options;
-    sdk.context.analysisOptions = options;
-    _context.sourceFactory =
-        new SourceFactory([dartUriResolver, new _AssetUriResolver(this)]);
-  }
-
-  LibraryElement getLibrary(AssetId assetId) {
-    var source = sources[assetId];
-    return source == null ? null : _context.computeLibraryElement(source);
-  }
-
-  Future<Resolver> resolve(Transform transform, [List<AssetId> entryPoints]) {
-    // Can only have one resolve in progress at a time, so chain the current
-    // resolution to be after the last one.
-    var phaseComplete = new Completer();
-    var future = _lastPhaseComplete.whenComplete(() {
-      _currentPhaseComplete = phaseComplete;
-      return _performResolve(transform,
-          entryPoints == null ? [transform.primaryInput.id] : entryPoints);
-    }).then((_) => this);
-    // Advance the lastPhaseComplete to be done when this phase is all done.
-    _lastPhaseComplete = phaseComplete.future;
-    return future;
-  }
-
-  void release() {
-    if (_currentPhaseComplete == null) {
-      throw new StateError('Releasing without current lock.');
-    }
-    _currentPhaseComplete.complete(null);
-    _currentPhaseComplete = null;
-
-    // Clear out libraries since they should not be referenced after release.
-    _entryLibraries = null;
-    _libraries = null;
-    _currentTransform = null;
-  }
-
-  Future _performResolve(Transform transform, List<AssetId> entryPoints) {
-    if (_currentTransform != null) {
-      throw new StateError('Cannot be accessed by concurrent transforms');
-    }
-    _currentTransform = transform;
-
-    // Basic approach is to start at the first file, update it's contents
-    // and see if it changed, then walk all files accessed by it.
-    var visited = new Set<AssetId>();
-    var visiting = new FutureGroup();
-    var toUpdate = [];
-
-    void processAsset(AssetId assetId) {
-      visited.add(assetId);
-
-      visiting.add(transform.readInputAsString(assetId).then((contents) {
-        var source = sources[assetId];
-        if (source == null) {
-          source = new _AssetBasedSource(assetId, this);
-          sources[assetId] = source;
-        }
-        source.updateDependencies(contents);
-        toUpdate.add(new _PendingUpdate(source, contents));
-        source.dependentAssets
-            .where((id) => !visited.contains(id))
-            .forEach(processAsset);
-      }, onError: (e) {
-        var source = sources[assetId];
-        if (source != null && source.exists()) {
-          _context.applyChanges(new ChangeSet()..removedSource(source));
-          sources[assetId].updateContents(null);
-        }
-      }));
-    }
-    entryPoints.forEach(processAsset);
-
-    // Once we have all asset sources updated with the new contents then
-    // resolve everything.
-    return visiting.future.then((_) {
-      var changeSet = new ChangeSet();
-      toUpdate.forEach((pending) => pending.apply(changeSet));
-      var unreachableAssets =
-          sources.keys.toSet().difference(visited).map((id) => sources[id]);
-      for (var unreachable in unreachableAssets) {
-        changeSet.removedSource(unreachable);
-        unreachable.updateContents(null);
-        sources.remove(unreachable.assetId);
-      }
-
-      // Update the analyzer context with the latest sources
-      _context.applyChanges(changeSet);
-      // Force resolve each entry point (the getter will ensure the library is
-      // computed first).
-      _entryLibraries = entryPoints.map((id) {
-        var source = sources[id];
-        if (source == null) return null;
-        return _context.computeLibraryElement(source);
-      }).toList();
-    });
-  }
-
-  Iterable<LibraryElement> get libraries {
-    if (_libraries == null) {
-      // Note: we don't use `lib.visibleLibraries` because that excludes the
-      // exports seen in the entry libraries.
-      _libraries = new Set<LibraryElement>();
-      _entryLibraries.forEach(_collectLibraries);
-    }
-    return _libraries;
-  }
-
-  void _collectLibraries(LibraryElement lib) {
-    if (lib == null || _libraries.contains(lib)) return;
-    _libraries.add(lib);
-    lib.importedLibraries.forEach(_collectLibraries);
-    lib.exportedLibraries.forEach(_collectLibraries);
-  }
-
-  LibraryElement getLibraryByName(String libraryName) =>
-      libraries.firstWhere((l) => l.name == libraryName, orElse: () => null);
-
-  LibraryElement getLibraryByUri(Uri uri) =>
-      libraries.firstWhere((l) => getImportUri(l) == uri, orElse: () => null);
-
-  ClassElement getType(String typeName) {
-    var dotIndex = typeName.lastIndexOf('.');
-    var libraryName = dotIndex == -1 ? '' : typeName.substring(0, dotIndex);
-
-    var className =
-        dotIndex == -1 ? typeName : typeName.substring(dotIndex + 1);
-
-    for (var lib in libraries.where((l) => l.name == libraryName)) {
-      var type = lib.getType(className);
-      if (type != null) return type;
-    }
-    return null;
-  }
-
-  Element getLibraryVariable(String variableName) {
-    var dotIndex = variableName.lastIndexOf('.');
-    var libraryName = dotIndex == -1 ? '' : variableName.substring(0, dotIndex);
-
-    var name =
-        dotIndex == -1 ? variableName : variableName.substring(dotIndex + 1);
-
-    return libraries
-        .where((lib) => lib.name == libraryName)
-        .expand((lib) => lib.units)
-        .expand((unit) => unit.topLevelVariables)
-        .firstWhere((variable) => variable.name == name, orElse: () => null);
-  }
-
-  Element getLibraryFunction(String fnName) {
-    var dotIndex = fnName.lastIndexOf('.');
-    var libraryName = dotIndex == -1 ? '' : fnName.substring(0, dotIndex);
-
-    var name = dotIndex == -1 ? fnName : fnName.substring(dotIndex + 1);
-
-    return libraries
-        .where((lib) => lib.name == libraryName)
-        .expand((lib) => lib.units)
-        .expand((unit) => unit.functions)
-        .firstWhere((fn) => fn.name == name, orElse: () => null);
-  }
-
-  EvaluationResult evaluateConstant(
-      LibraryElement library, Expression expression) {
-    return new ConstantEvaluator(library.source, _context.typeProvider)
-        .evaluate(expression);
-  }
-
-  Uri getImportUri(LibraryElement lib, {AssetId from}) =>
-      _getSourceUri(lib, from: from);
-
-  /// Similar to getImportUri but will get the part URI for parts rather than
-  /// the library URI.
-  Uri _getSourceUri(Element element, {AssetId from}) {
-    var source = element.source;
-    if (source is _AssetBasedSource) {
-      var uriString = assetIdToUri(source.assetId, from: from);
-      return uriString != null ? Uri.parse(uriString) : null;
-    } else if (source is UriAnnotatedSource) {
-      return source.uri;
-    }
-    // Should not be able to encounter any other source types.
-    throw new StateError('Unable to resolve URI for ${source.runtimeType}');
-  }
-
-  AssetId getSourceAssetId(Element element) {
-    var source = element.source;
-    if (source is _AssetBasedSource) return source.assetId;
-    return null;
-  }
-
-  SourceSpan getSourceSpan(Element element) {
-    var sourceFile = getSourceFile(element);
-    if (sourceFile == null) return null;
-    return sourceFile.span(element.node.offset, element.node.end);
-  }
-
-  TextEditTransaction createTextEditTransaction(Element element) {
-    if (element.source is! _AssetBasedSource) return null;
-
-    // Cannot edit unless there is an active transformer.
-    if (_currentTransform == null) return null;
-
-    _AssetBasedSource source = element.source;
-    // Cannot modify assets in other packages.
-    if (source.assetId.package != _currentTransform.primaryInput.id.package) {
-      return null;
-    }
-
-    var sourceFile = getSourceFile(element);
-    if (sourceFile == null) return null;
-
-    return new TextEditTransaction(source.rawContents, sourceFile);
-  }
-
-  /// Gets the SourceFile for the source of the element.
-  SourceFile getSourceFile(Element element) {
-    var assetId = getSourceAssetId(element);
-    if (assetId == null) return null;
-
-    var importUri = _getSourceUri(element);
-    var spanPath = importUri != null ? importUri.toString() : assetId.path;
-    return new SourceFile(sources[assetId].rawContents, url: spanPath);
-  }
-}
-
-/// Implementation of Analyzer's Source for Barback based assets.
-class _AssetBasedSource extends Source {
-
-  /// Asset ID where this source can be found.
-  final AssetId assetId;
-
-  /// The resolver this is being used in.
-  final ResolverImpl _resolver;
-
-  /// Cache of dependent asset IDs, to avoid re-parsing the AST.
-  Iterable<AssetId> _dependentAssets;
-
-  /// The current revision of the file, incremented only when file changes.
-  int _revision = 0;
-
-  /// The file contents.
-  String _contents;
-
-  _AssetBasedSource(this.assetId, this._resolver);
-
-  /// Update the dependencies of this source. This parses [contents] but avoids
-  /// any analyzer resolution.
-  void updateDependencies(String contents) {
-    if (contents == _contents) return;
-    var unit = parseDirectives(contents, suppressErrors: true);
-    _dependentAssets = unit.directives
-        .where((d) => (d is ImportDirective ||
-            d is PartDirective ||
-            d is ExportDirective))
-        .map((d) => _resolve(
-            assetId, d.uri.stringValue, _logger, _getSpan(d, contents)))
-        .where((id) => id != null)
-        .toSet();
-  }
-
-  /// Update the contents of this file with [contents].
-  ///
-  /// Returns true if the contents of this asset have changed.
-  bool updateContents(String contents) {
-    if (contents == _contents) return false;
-    _contents = contents;
-    ++_revision;
-    return true;
-  }
-
-  /// Contents of the file.
-  TimestampedData<String> get contents {
-    if (!exists()) throw new StateError('$assetId does not exist');
-
-    return new TimestampedData<String>(modificationStamp, _contents);
-  }
-
-  /// Contents of the file.
-  String get rawContents => _contents;
-
-  Uri get uri => Uri.parse('asset:${assetId.package}/${assetId.path}');
-
-  /// Logger for the current transform.
-  ///
-  /// Only valid while the resolver is updating assets.
-  TransformLogger get _logger => _resolver._currentTransform.logger;
-
-  /// Gets all imports/parts/exports which resolve to assets (non-Dart files).
-  Iterable<AssetId> get dependentAssets => _dependentAssets;
-
-  bool exists() => _contents != null;
-
-  bool operator ==(Object other) =>
-      other is _AssetBasedSource && assetId == other.assetId;
-
-  int get hashCode => assetId.hashCode;
-
-  void getContentsToReceiver(Source_ContentReceiver receiver) {
-    receiver.accept(rawContents, modificationStamp);
-  }
-
-  String get encoding =>
-      "${uriKind.encoding}${assetId.package}/${assetId.path}";
-
-  String get fullName => assetId.toString();
-
-  int get modificationStamp => _revision;
-
-  String get shortName => path.basename(assetId.path);
-
-  UriKind get uriKind {
-    if (assetId.path.startsWith('lib/')) return UriKind.PACKAGE_URI;
-    return UriKind.FILE_URI;
-  }
-
-  bool get isInSystemLibrary => false;
-
-  Source resolveRelative(Uri relativeUri) {
-    var id = _resolve(assetId, relativeUri.toString(), _logger, null);
-    if (id == null) return null;
-
-    // The entire AST should have been parsed and loaded at this point.
-    var source = _resolver.sources[id];
-    if (source == null) {
-      _logger.error('Could not load asset $id');
-    }
-    return source;
-  }
-
-  Uri resolveRelativeUri(Uri relativeUri) {
-    var id = _resolve(assetId, relativeUri.toString(), _logger, null);
-    if (id == null) return uri.resolveUri(relativeUri);
-
-    // The entire AST should have been parsed and loaded at this point.
-    var source = _resolver.sources[id];
-    if (source == null) {
-      _logger.error('Could not load asset $id');
-    }
-    return source.uri;
-  }
-
-  /// For logging errors.
-  SourceSpan _getSpan(AstNode node, [String contents]) =>
-      _getSourceFile(contents).span(node.offset, node.end);
-  /// For logging errors.
-  SourceFile _getSourceFile([String contents]) {
-    var uri = assetIdToUri(assetId);
-    var path = uri != null ? uri : assetId.path;
-    return new SourceFile(contents != null ? contents : rawContents, url: path);
-  }
-}
-
-/// Implementation of Analyzer's UriResolver for Barback based assets.
-class _AssetUriResolver implements UriResolver {
-  final ResolverImpl _resolver;
-  _AssetUriResolver(this._resolver);
-
-  Source resolveAbsolute(Uri uri) {
-    assert(uri.scheme != 'dart');
-    var assetId;
-    if (uri.scheme == 'asset') {
-      var parts = path.split(uri.path);
-      assetId = new AssetId(parts[0], path.joinAll(parts.skip(1)));
-    } else {
-      assetId = _resolve(null, uri.toString(), logger, null);
-      if (assetId == null) {
-        logger.error('Unable to resolve asset ID for "$uri"');
-        return null;
-      }
-    }
-    var source = _resolver.sources[assetId];
-    // Analyzer expects that sources which are referenced but do not exist yet
-    // still exist, so just make an empty source.
-    if (source == null) {
-      source = new _AssetBasedSource(assetId, _resolver);
-      _resolver.sources[assetId] = source;
-    }
-    return source;
-  }
-
-  Source fromEncoding(UriKind kind, Uri uri) =>
-      throw new UnsupportedError('fromEncoding is not supported');
-
-  Uri restoreAbsolute(Source source) =>
-      throw new UnsupportedError('restoreAbsolute is not supported');
-
-  TransformLogger get logger => _resolver._currentTransform.logger;
-}
-
-/// Get an asset ID for a URL relative to another source asset.
-AssetId _resolve(
-    AssetId source, String url, TransformLogger logger, SourceSpan span) {
-  if (url == null || url == '') return null;
-  var uri = Uri.parse(url);
-
-  // Workaround for dartbug.com/17156- pub transforms package: imports from
-  // files of the transformers package to have absolute /packages/ URIs.
-  if (uri.scheme == '' &&
-      path.isAbsolute(url) &&
-      uri.pathSegments[0] == 'packages') {
-    uri = Uri.parse('package:${uri.pathSegments.skip(1).join(path.separator)}');
-  }
-
-  if (uri.scheme == 'package') {
-    var segments = new List.from(uri.pathSegments);
-    var package = segments[0];
-    segments[0] = 'lib';
-    return new AssetId(package, segments.join(path.separator));
-  }
-  // Dart SDK libraries do not have assets.
-  if (uri.scheme == 'dart') return null;
-
-  return uriToAssetId(source, url, logger, span);
-}
-
-/// A completer that waits until all added [Future]s complete.
-// TODO(blois): Copied from quiver. Remove from here when it gets
-// added to dart:core. (See #6626.)
-class FutureGroup<E> {
-  static const _FINISHED = -1;
-
-  int _pending = 0;
-  Future _failedTask;
-  final Completer<List> _completer = new Completer<List>();
-  final List results = [];
-
-  /** Gets the task that failed, if any. */
-  Future get failedTask => _failedTask;
-
-  /**
-   * Wait for [task] to complete.
-   *
-   * If this group has already been marked as completed, a [StateError] will be
-   * thrown.
-   *
-   * If this group has a [failedTask], new tasks will be ignored, because the
-   * error has already been signaled.
-   */
-  void add(Future task) {
-    if (_failedTask != null) return;
-    if (_pending == _FINISHED) throw new StateError("Future already completed");
-
-    _pending++;
-    var i = results.length;
-    results.add(null);
-    task.then((res) {
-      results[i] = res;
-      if (_failedTask != null) return;
-      _pending--;
-      if (_pending == 0) {
-        _pending = _FINISHED;
-        _completer.complete(results);
-      }
-    }, onError: (e, s) {
-      if (_failedTask != null) return;
-      _failedTask = task;
-      _completer.completeError(e, s);
-    });
-  }
-
-  /**
-   * A Future that completes with a List of the values from all the added
-   * tasks, when they have all completed.
-   *
-   * If any task fails, this Future will receive the error. Only the first
-   * error will be sent to the Future.
-   */
-  Future<List<E>> get future => _completer.future;
-}
-
-/// A pending update to notify the resolver that a [Source] has been added or
-/// changed. This is used by the `_performResolve` algorithm above to apply all
-/// changes after it first discovers the transitive closure of files that are
-/// reachable from the sources.
-class _PendingUpdate {
-  _AssetBasedSource source;
-  String content;
-
-  _PendingUpdate(this.source, this.content);
-
-  void apply(ChangeSet changeSet) {
-    if (!source.updateContents(content)) return;
-    if (source._revision == 1 && source._contents != null) {
-      changeSet.addedSource(source);
-    } else {
-      changeSet.changedSource(source);
-    }
-  }
-}