add resolve(id) to BuildStep

lib/build.dart

@@ -1,6 +1,7 @@
 // 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.
+export 'src/analyzer/resolver.dart';
 export 'src/asset/asset.dart';
 export 'src/asset/exceptions.dart';
 export 'src/asset/file_based.dart';

lib/src/analyzer/resolver.dart

@@ -0,0 +1,118 @@
+// 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.
+import 'dart:async';
+
+import 'package:analyzer/analyzer.dart' show Expression;
+import 'package:analyzer/src/generated/constant.dart' show EvaluationResult;
+import 'package:analyzer/src/generated/element.dart';
+import 'package:code_transformers/resolver.dart' as code_transformers
+    show Resolver;
+import 'package:source_maps/refactor.dart';
+import 'package:source_span/source_span.dart';
+
+import '../asset/id.dart';
+import '../builder/build_step.dart';
+import '../util/barback.dart';
+
+class Resolver {
+  final code_transformers.Resolver resolver;
+
+  Resolver(this.resolver);
+
+  /// Update the status of all the sources referenced by the entry points and
+  /// update the resolved library. If [entryPoints] is omitted, the input
+  /// asset of [buildStep] is used as the only entry point.
+  ///
+  /// [release] must be called when done handling this [Resolver] to allow it
+  /// to be used by later phases.
+  Future<Resolver> resolve(BuildStep buildStep,
+      [List<AssetId> entryPoints]) async {
+    return new Resolver(await resolver.resolve(toBarbackTransform(buildStep),
+        entryPoints?.map(toBarbackAssetId)?.toList()));
+  }
+
+  /// Release this resolver so it can be updated by following build steps.
+  void release() => resolver.release();
+
+  /// Gets the resolved Dart library for an asset, or null if the AST has not
+  /// been resolved.
+  ///
+  /// If the AST has not been resolved then this normally means that the
+  /// transformer hosting this needs to be in an earlier phase.
+  LibraryElement getLibrary(AssetId assetId) =>
+      resolver.getLibrary(toBarbackAssetId(assetId));
+
+  /// Gets all libraries accessible from the entry point, recursively.
+  ///
+  /// This includes all Dart SDK libraries as well.
+  Iterable<LibraryElement> get libraries => resolver.libraries;
+
+  /// Finds the first library identified by [libraryName], or null if no
+  /// library can be found.
+  LibraryElement getLibraryByName(String libraryName) =>
+      resolver.getLibraryByName(libraryName);
+
+  /// Finds the first library identified by [libraryName], or null if no
+  /// library can be found.
+  ///
+  /// [uri] must be an absolute URI of the form
+  /// `[dart:|package:]path/file.dart`.
+  LibraryElement getLibraryByUri(Uri uri) => resolver.getLibraryByUri(uri);
+
+  /// Resolves a fully-qualified type name (library_name.ClassName).
+  ///
+  /// This will resolve the first instance of [typeName], because of potential
+  /// library name conflicts the name is not guaranteed to be unique.
+  ClassElement getType(String typeName) => resolver.getType(typeName);
+
+  /// Resolves a fully-qualified top-level library variable
+  /// (library_name.variableName).
+  ///
+  /// This will resolve the first instance of [variableName], because of
+  /// potential library name conflicts the name is not guaranteed to be unique.
+  Element getLibraryVariable(String variableName) =>
+      resolver.getLibraryVariable(variableName);
+
+  /// Resolves a fully-qualified top-level library function
+  /// (library_name.functionName).
+  ///
+  /// This will resolve the first instance of [functionName], because of
+  /// potential library name conflicts the name is not guaranteed to be unique.
+  Element getLibraryFunction(String functionName) =>
+      resolver.getLibraryFunction(functionName);
+
+  /// Gets the result of evaluating the constant [expression] in the context of
+  /// a [library].
+  EvaluationResult evaluateConstant(
+          LibraryElement library, Expression expression) =>
+      resolver.evaluateConstant(library, expression);
+
+  /// Gets an URI appropriate for importing the specified library.
+  ///
+  /// Returns null if the library cannot be imported via an absolute URI or
+  /// from [from] (if provided).
+  Uri getImportUri(LibraryElement lib, {AssetId from}) => resolver
+      .getImportUri(lib, from: from == null ? null : toBarbackAssetId(from));
+
+  /// Get the asset ID of the file containing the asset.
+  AssetId getSourceAssetId(Element element) =>
+      toBuildAssetId(resolver.getSourceAssetId(element));
+
+  /// Get the source span where the specified element was defined or null if
+  /// the element came from the Dart SDK.
+  SourceSpan getSourceSpan(Element element) => resolver.getSourceSpan(element);
+
+  /// Get a [SourceFile] with the contents of the file that defines [element],
+  /// or null if the element came from the Dart SDK.
+  SourceFile getSourceFile(Element element) => resolver.getSourceFile(element);
+
+  /// Creates a text edit transaction for the given element if it is able
+  /// to be edited, returns null otherwise.
+  ///
+  /// The transaction contains the entire text of the source file where the
+  /// element originated. If the element was from a library part then the
+  /// source file is the part file rather than the library.
+  TextEditTransaction createTextEditTransaction(Element element) =>
+      resolver.createTextEditTransaction(element);
+}

lib/src/builder/build_step.dart

@@ -4,6 +4,7 @@
 import 'dart:async';
 import 'dart:convert';
 
+import '../analyzer/resolver.dart';
 import '../asset/asset.dart';
 import '../asset/id.dart';
 
@@ -22,4 +23,8 @@ abstract class BuildStep {
   /// Outputs an [Asset] using the current [AssetWriter], and adds [asset] to
   /// [outputs].
   void writeAsString(Asset asset, {Encoding encoding: UTF8});
+
+  /// Gives a [Resolver] for [id]. This must be released when it is done being
+  /// used.
+  Future<Resolver> resolve(id);
 }

lib/src/builder/build_step_impl.dart

@@ -5,16 +5,23 @@ import 'dart:async';
 import 'dart:collection';
 import 'dart:convert';
 
+import 'package:code_transformers/resolver.dart' as code_transformers;
+
+import '../analyzer/resolver.dart';
 import '../asset/asset.dart';
 import '../asset/id.dart';
 import '../asset/reader.dart';
 import '../asset/writer.dart';
+import '../util/barback.dart';
 import 'build_step.dart';
 import 'exceptions.dart';
 
 /// A single step in the build processes. This represents a single input and
 /// its expected and real outputs. It also handles tracking of dependencies.
 class BuildStepImpl implements BuildStep {
+  static code_transformers.Resolvers _resolvers =
+      new code_transformers.Resolvers(code_transformers.dartSdkDirectory);
+
   /// The primary input for this build step.
   @override
   final Asset input;
@@ -76,4 +83,8 @@ class BuildStepImpl implements BuildStep {
     var done = _writer.writeAsString(asset, encoding: encoding);
     _outputsCompleted = _outputsCompleted.then((_) => done);
   }
+
+  /// Resolves [id] and returns a [Future<Resolver>] once that is done.
+  Future<Resolver> resolve(AssetId id) async => new Resolver(
+      await _resolvers.get(toBarbackTransform(this), [toBarbackAssetId(id)]));
 }

lib/src/transformer/transformer.dart

@@ -13,6 +13,7 @@ import '../asset/reader.dart';
 import '../asset/writer.dart';
 import '../builder/builder.dart';
 import '../builder/build_step_impl.dart';
+import '../util/barback.dart';
 
 /// A [Transformer] which runs multiple [Builder]s.
 /// Extend this class and define the [builders] getter to create a [Transformer]
@@ -39,7 +40,7 @@ abstract class BuilderTransformer implements Transformer, DeclaringTransformer {
 
   @override
   Future apply(Transform transform) async {
-    var input = await _toBuildAsset(transform.primaryInput);
+    var input = await toBuildAsset(transform.primaryInput);
     var reader = new _TransformAssetReader(transform);
     var writer = new _TransformAssetWriter(transform);
 
@@ -56,8 +57,8 @@ abstract class BuilderTransformer implements Transformer, DeclaringTransformer {
       var preExistingFiles = [];
       for (var output in expected) {
         if (!allExpected.add(output) ||
-            await transform.hasInput(_toBarbackAssetId(output))) {
-          preExistingFiles.add(_toBarbackAssetId(output));
+            await transform.hasInput(toBarbackAssetId(output))) {
+          preExistingFiles.add(toBarbackAssetId(output));
         }
       }
       if (preExistingFiles.isNotEmpty) {
@@ -78,7 +79,7 @@ abstract class BuilderTransformer implements Transformer, DeclaringTransformer {
   @override
   void declareOutputs(DeclaringTransform transform) {
     for (var outputId in _expectedOutputs(transform.primaryId, builders)) {
-      transform.declareOutput(_toBarbackAssetId(outputId));
+      transform.declareOutput(toBarbackAssetId(outputId));
     }
   }
 }
@@ -91,11 +92,11 @@ class _TransformAssetReader implements AssetReader {
 
   @override
   Future<bool> hasInput(build.AssetId id) =>
-      transform.hasInput(_toBarbackAssetId(id));
+      transform.hasInput(toBarbackAssetId(id));
 
   @override
   Future<String> readAsString(build.AssetId id, {Encoding encoding: UTF8}) =>
-      transform.readInputAsString(_toBarbackAssetId(id), encoding: encoding);
+      transform.readInputAsString(toBarbackAssetId(id), encoding: encoding);
 }
 
 /// Very simple [AssetWriter] which uses a [Transform].
@@ -106,7 +107,7 @@ class _TransformAssetWriter implements AssetWriter {
 
   @override
   Future writeAsString(build.Asset asset, {Encoding encoding: UTF8}) {
-    transform.addOutput(_toBarbackAsset(asset));
+    transform.addOutput(toBarbackAsset(asset));
     return new Future.value(null);
   }
 }
@@ -115,19 +116,6 @@ class _TransformAssetWriter implements AssetWriter {
 Iterable<build.AssetId> _expectedOutputs(
     barback.AssetId id, Iterable<Builder> builders) sync* {
   for (var builder in builders) {
-    yield* builder.declareOutputs(_toBuildAssetId(id));
+    yield* builder.declareOutputs(toBuildAssetId(id));
   }
 }
-
-barback.AssetId _toBarbackAssetId(build.AssetId id) =>
-    new barback.AssetId(id.package, id.path);
-
-build.AssetId _toBuildAssetId(barback.AssetId id) =>
-    new build.AssetId(id.package, id.path);
-
-barback.Asset _toBarbackAsset(build.Asset asset) =>
-    new barback.Asset.fromString(
-        _toBarbackAssetId(asset.id), asset.stringContents);
-
-Future<build.Asset> _toBuildAsset(barback.Asset asset) async =>
-    new build.Asset(_toBuildAssetId(asset.id), await asset.readAsString());

lib/src/util/barback.dart

@@ -0,0 +1,78 @@
+// 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.
+import 'dart:async';
+import 'dart:convert';
+
+import 'package:barback/barback.dart' as barback;
+
+import '../asset/asset.dart' as build;
+import '../asset/id.dart' as build;
+import '../builder/build_step.dart' as build;
+
+barback.AssetId toBarbackAssetId(build.AssetId id) =>
+    new barback.AssetId(id.package, id.path);
+
+build.AssetId toBuildAssetId(barback.AssetId id) =>
+    new build.AssetId(id.package, id.path);
+
+barback.Asset toBarbackAsset(build.Asset asset) => new barback.Asset.fromString(
+    toBarbackAssetId(asset.id), asset.stringContents);
+
+Future<build.Asset> toBuildAsset(barback.Asset asset) async =>
+    new build.Asset(toBuildAssetId(asset.id), await asset.readAsString());
+
+barback.Transform toBarbackTransform(build.BuildStep buildStep) =>
+    new BuildStepTransform(buildStep);
+
+class BuildStepTransform implements barback.Transform {
+  final build.BuildStep buildStep;
+
+  BuildStepTransform(this.buildStep);
+
+  @override
+  barback.Asset get primaryInput => toBarbackAsset(buildStep.input);
+
+  @override
+  barback.TransformLogger get logger =>
+      new barback.TransformLogger((asset, level, message, span) {
+        var buffer = new StringBuffer();
+        buffer.write('$level: ');
+        if (asset != null) {
+          buffer.write('From $asset');
+          if (span != null) {
+            buffer.write('()$span)');
+          }
+          buffer.write(': ');
+        }
+        buffer.write(message);
+        print(buffer);
+      });
+
+  @override
+  Future<barback.Asset> getInput(barback.AssetId id, {Encoding encoding}) =>
+      throw new UnimplementedError();
+
+  @override
+  Future<String> readInputAsString(barback.AssetId id, {Encoding encoding}) {
+    return buildStep.readAsString(toBuildAssetId(id), encoding: encoding);
+  }
+
+  @override
+  Stream<List<int>> readInput(barback.AssetId id) =>
+      throw new UnimplementedError();
+
+  @override
+  Future<bool> hasInput(barback.AssetId id) =>
+      buildStep.hasInput(toBuildAssetId(id));
+
+  @override
+  void addOutput(barback.Asset output) {
+    toBuildAsset(output).then((asset) {
+      buildStep.writeAsString(asset);
+    });
+  }
+
+  @override
+  void consumePrimary() => throw new UnimplementedError();
+}

pubspec.yaml

@@ -8,9 +8,13 @@ environment:
   sdk: '>=1.9.1 <2.0.0'
 
 dependencies:
+  analyzer: ^0.27.1
   barback: ^0.15.0
+  code_transformers: ^0.4.0
   glob: ^1.1.0
   path: ^1.1.0
+  source_maps: '>=0.9.4 <0.11.0'
+  source_span: '>=1.0.0 <2.0.0'
   stack_trace: ^1.6.0
   yaml: ^2.1.0