Adding Angular and dependent packages for testing

third_party/pkg/angular/lib/tools/source_crawler_impl.dart

+library angular.source_crawler_impl;
+
+import 'dart:io';
+import 'package:analyzer/analyzer.dart';
+import 'source_crawler.dart';
+
+const String PACKAGE_PREFIX = 'package:';
+
+/**
+ * Dart source file crawler. As it crawls Dart source, it calls
+ * [CompilationUnitVisitor] on each file.
+ */
+class SourceCrawlerImpl implements SourceCrawler {
+  final List<String> packageRoots;
+
+  SourceCrawlerImpl(this.packageRoots);
+
+  void crawl(String entryPoint, CompilationUnitVisitor visitor) {
+    List<String> visited = <String>[];
+    List<String> toVisit = <String>[];
+    if (entryPoint.startsWith(PACKAGE_PREFIX)) {
+      var path = resolvePackagePath(entryPoint);
+      if (path == null) {
+        throw 'Unable to resolve $entryPoint';
+      }
+      toVisit.add(path);
+    } else {
+      toVisit.add(entryPoint);
+    }
+
+    while (toVisit.isNotEmpty) {
+      var currentFile = toVisit.removeAt(0);
+      visited.add(currentFile);
+      var file = new File(currentFile);
+      // Possible source file doesn't exist. For example if it is generated.
+      if (!file.existsSync()) continue;
+      var currentDir = file.parent.path;
+      CompilationUnit cu = parseDartFile(currentFile);
+      processImports(cu, currentDir, currentFile, visited, toVisit);
+      visitor(cu);
+    }
+  }
+
+  void processImports(CompilationUnit cu, String currentDir,
+                      String currentFile, List<String> visited,
+                      List<String> toVisit) {
+    cu.directives.forEach((Directive directive) {
+      if (directive is ImportDirective || directive is PartDirective) {
+        UriBasedDirective import = directive;
+        String canonicalFile = canonicalizeImportPath(
+            currentDir, currentFile, import.uri.stringValue);
+        if (canonicalFile == null) return;
+        if (!visited.contains(canonicalFile) &&
+            !toVisit.contains(canonicalFile)) {
+          toVisit.add(canonicalFile);
+        }
+      }
+    });
+  }
+
+  String canonicalizeImportPath(String currentDir,
+                                String currentFile,
+                                String uri) {
+    // ignore core libraries
+    if (uri.startsWith('dart:')) {
+      return null;
+    }
+    if (uri.startsWith(PACKAGE_PREFIX)) {
+      return resolvePackagePath(uri);
+    }
+    // relative import.
+    if (uri.startsWith('../')) {
+      while (uri.startsWith('../')) {
+        uri = uri.substring('../'.length);
+        currentDir = currentDir.substring(0, currentDir.lastIndexOf('/'));
+      }
+    }
+    return '$currentDir/$uri';
+  }
+
+  String resolvePackagePath(String uri) {
+    for (String packageRoot in packageRoots) {
+      var resolvedPath = _packageUriResolver(uri, packageRoot);
+      if (new File(resolvedPath).existsSync()) {
+        return resolvedPath;
+      }
+    }
+    return null;
+  }
+
+  String _packageUriResolver(String uri, String packageRoot) {
+    var packagePath = uri.substring(PACKAGE_PREFIX.length);
+    if (!packageRoot.endsWith('/')) {
+      packageRoot = packageRoot + '/';
+    }
+    return packageRoot + packagePath;
+  }
+}