Make exclude list also exclude contexts

- Only create a context if the directory/.packages/pubspec.yaml is not excluded.
- Add tests.

Fixes: https://github.com/dart-lang/sdk/issues/23941

R=brianwilkerson@google.com, devoncarew@google.com, paulberry@google.com, pquitslund@google.com

Review URL: https://codereview.chromium.org//1263443005 .

pkg/analysis_server/lib/src/context_manager.dart

@@ -844,9 +844,13 @@ class ContextManagerImpl implements ContextManager {
       packageSpec = folder.getChild(PUBSPEC_NAME);
     }
 
-    bool parentCreated = false;
+    bool createContext = packageSpec.exists || !withPackageSpecOnly;
-    if (packageSpec.exists || !withPackageSpecOnly) {
+    if (withPackageSpecOnly && packageSpec.exists &&
-      parentCreated = true;
+        (parent != null) && parent.ignored(packageSpec.path)) {
+      // Don't create a context if the package spec is required and ignored.
+      createContext = false;
+    }
+    if (createContext) {
       parent = _createContext(parent, folder, packageSpec);
     }
 
@@ -854,7 +858,9 @@ class ContextManagerImpl implements ContextManager {
     try {
       for (Resource child in folder.getChildren()) {
         if (child is Folder) {
-          _createContexts(parent, child, true);
+          if (!parent.ignored(child.path)) {
+            _createContexts(parent, child, true);
+          }
         }
       }
     } on FileSystemException {
@@ -862,7 +868,7 @@ class ContextManagerImpl implements ContextManager {
       // are no subfolders that need to be added.
     }
 
-    if (parentCreated) {
+    if (createContext) {
       // Now that the child contexts have been created, add the sources that
       // don't belong to the children.
       ChangeSet changeSet = new ChangeSet();

pkg/analysis_server/test/context_manager_test.dart

@@ -231,6 +231,96 @@ analyzer:
     expect(files[0], equals('/my/proj/lib/main.dart'));
   }
 
+  test_path_filter_child_contexts_option() async {
+    // Create files.
+    String libPath = newFolder([projPath, LIB_NAME]);
+    newFile([libPath, 'main.dart']);
+    newFile([libPath, 'pubspec.yaml'], r'''
+name: foobar
+''');
+    String otherLibPath = newFolder([projPath, 'other_lib']);
+    newFile([otherLibPath, 'entry.dart']);
+    newFile([otherLibPath, 'pubspec.yaml'], r'''
+name: other_lib
+''');
+    // Setup analysis options file with ignore list that ignores the 'other_lib'
+    // directory by name.
+    newFile([projPath, '.analysis_options'], r'''
+analyzer:
+  exclude:
+    - 'other_lib'
+''');
+    // Setup context.
+    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
+    // Verify that the context in other_lib wasn't created and that the
+    // context in lib was created.
+    var contexts = manager.contextsInAnalysisRoot(
+        resourceProvider.newFolder(projPath));
+    expect(contexts.length, 2);
+    expect(contexts[0].name, equals('/my/proj'));
+    expect(contexts[1].name, equals('/my/proj/lib'));
+  }
+
+  test_path_filter_wildcard_child_contexts_option() async {
+    // Create files.
+    String libPath = newFolder([projPath, LIB_NAME]);
+    newFile([libPath, 'main.dart']);
+    newFile([libPath, 'pubspec.yaml'], r'''
+name: foobar
+''');
+    String otherLibPath = newFolder([projPath, 'other_lib']);
+    newFile([otherLibPath, 'entry.dart']);
+    newFile([otherLibPath, 'pubspec.yaml'], r'''
+name: other_lib
+''');
+    // Setup analysis options file with ignore list that ignores 'other_lib'
+    // and all immediate children.
+    newFile([projPath, '.analysis_options'], r'''
+analyzer:
+  exclude:
+    - 'other_lib/*'
+''');
+    // Setup context.
+    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
+    // Verify that the context in other_lib wasn't created and that the
+    // context in lib was created.
+    var contexts = manager.contextsInAnalysisRoot(
+        resourceProvider.newFolder(projPath));
+    expect(contexts.length, 2);
+    expect(contexts[0].name, equals('/my/proj'));
+    expect(contexts[1].name, equals('/my/proj/lib'));
+  }
+
+  test_path_filter_recursive_wildcard_child_contexts_option() async {
+    // Create files.
+    String libPath = newFolder([projPath, LIB_NAME]);
+    newFile([libPath, 'main.dart']);
+    newFile([libPath, 'pubspec.yaml'], r'''
+  name: foobar
+  ''');
+    String otherLibPath = newFolder([projPath, 'other_lib']);
+    newFile([otherLibPath, 'entry.dart']);
+    newFile([otherLibPath, 'pubspec.yaml'], r'''
+  name: other_lib
+  ''');
+    // Setup analysis options file with ignore list that ignores 'other_lib'
+    // and all descendants.
+    newFile([projPath, '.analysis_options'], r'''
+analyzer:
+  exclude:
+    - 'other_lib/**'
+  ''');
+    // Setup context.
+    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
+    // Verify that the context in other_lib wasn't created and that the
+    // context in lib was created.
+    var contexts = manager.contextsInAnalysisRoot(
+        resourceProvider.newFolder(projPath));
+    expect(contexts.length, 2);
+    expect(contexts[0].name, equals('/my/proj'));
+    expect(contexts[1].name, equals('/my/proj/lib'));
+  }
+
   test_refresh_folder_with_packagespec() {
     // create a context with a .packages file
     String packagespecFile = posix.join(projPath, '.packages');

pkg/analyzer/lib/source/path_filter.dart

@@ -62,4 +62,13 @@ class PathFilter {
 
   /// Returns the relative portion of [path] from [root].
   String _relative(String path) => pathContext.relative(path, from: root);
+
+  String toString() {
+    StringBuffer sb = new StringBuffer();
+    for (var pattern in _ignorePatterns) {
+      sb.write('$pattern ');
+    }
+    sb.writeln('');
+    return sb.toString();
+  }
 }