feat(di): added context to runtime DI errors

modules/angular2/src/core/compiler/element_injector.ts

@@ -419,6 +419,9 @@ export class ProtoElementInjector {
   getBindingAtIndex(index: number): any { return this.protoInjector.getBindingAtIndex(index); }
 }
 
+class _Context {
+  constructor(public element: any, public componentElement: any, public injector: any) {}
+}
 
 export class ElementInjector extends TreeNode<ElementInjector> implements DependencyProvider {
   private _host: ElementInjector;
@@ -438,7 +441,9 @@ export class ElementInjector extends TreeNode<ElementInjector> implements Depend
   constructor(public _proto: ProtoElementInjector, parent: ElementInjector) {
     super(parent);
 
-    this._injector = new Injector(this._proto.protoInjector, null, this);
+    this._injector =
+        new Injector(this._proto.protoInjector, null, this, () => this._debugContext());
+
     // we couple ourselves to the injector strategy to avoid polymoprhic calls
     var injectorStrategy = <any>this._injector.internalStrategy;
     this._strategy = injectorStrategy instanceof InjectorInlineStrategy ?
@@ -489,6 +494,12 @@ export class ElementInjector extends TreeNode<ElementInjector> implements Depend
     this.hydrated = true;
   }
 
+  private _debugContext(): any {
+    var p = this._preBuiltObjects;
+    return new _Context(p.elementRef.nativeElement, p.view.getHostElement().nativeElement,
+                        this._injector);
+  }
+
   private _reattachInjectors(imperativelyCreatedInjector: Injector): void {
     // Dynamically-loaded component in the template. Not a root ElementInjector.
     if (isPresent(this._parent)) {
@@ -613,7 +624,7 @@ export class ElementInjector extends TreeNode<ElementInjector> implements Depend
           return null;
         }
 
-        throw new NoBindingError(dirDep.key);
+        throw new NoBindingError(null, dirDep.key);
       }
       return this._preBuiltObjects.templateRef;
     }

modules/angular2/src/core/compiler/view.ts

@@ -200,6 +200,11 @@ export class AppView implements ChangeDispatcher, RenderEventDispatcher {
     return isPresent(viewIndex) ? this.views[viewIndex] : null;
   }
 
+  getHostElement(): ElementRef {
+    var boundElementIndex = this.mainMergeMapping.hostElementIndicesByViewIndex[this.viewOffset];
+    return this.elementRefs[boundElementIndex];
+  }
+
   getDetectorFor(directive: DirectiveIndex): any {
     var childView = this.getNestedView(this.elementOffset + directive.elementIndex);
     return isPresent(childView) ? childView.changeDetector : null;

modules/angular2/src/di/exceptions.ts

@@ -1,5 +1,7 @@
 import {ListWrapper, List} from 'angular2/src/facade/collection';
 import {stringify, BaseException, isBlank} from 'angular2/src/facade/lang';
+import {Key} from './key';
+import {Injector} from './injector';
 
 function findFirstClosedCycle(keys: List<any>): List<any> {
   var res = [];
@@ -31,22 +33,27 @@ function constructResolvingPath(keys: List<any>): string {
 export class AbstractBindingError extends BaseException {
   name: string;
   message: string;
-  keys: List<any>;
+  keys: List<Key>;
+  injectors: List<Injector>;
   constructResolvingMessage: Function;
-  // TODO(tbosch): Can't do key:Key as this results in a circular dependency!
-  constructor(key, constructResolvingMessage: Function, originalException?, originalStack?) {
-    super(null, originalException, originalStack);
+
+  constructor(injector: Injector, key: Key, constructResolvingMessage: Function, originalException?,
+              originalStack?) {
+    super("DI Exception", originalException, originalStack, null);
     this.keys = [key];
+    this.injectors = [injector];
     this.constructResolvingMessage = constructResolvingMessage;
     this.message = this.constructResolvingMessage(this.keys);
   }
 
-  // TODO(tbosch): Can't do key:Key as this results in a circular dependency!
-  addKey(key: any): void {
+  addKey(injector: Injector, key: Key): void {
+    this.injectors.push(injector);
     this.keys.push(key);
     this.message = this.constructResolvingMessage(this.keys);
   }
 
+  get context() { return this.injectors[this.injectors.length - 1].debugContext(); }
+
   toString(): string { return this.message; }
 }
 
@@ -55,47 +62,14 @@ export class AbstractBindingError extends BaseException {
  * {@link Injector} does not have a {@link Binding} for {@link Key}.
  */
 export class NoBindingError extends AbstractBindingError {
-  // TODO(tbosch): Can't do key:Key as this results in a circular dependency!
-  constructor(key) {
-    super(key, function(keys: List<any>) {
+  constructor(injector: Injector, key: Key) {
+    super(injector, key, function(keys: List<any>) {
       var first = stringify(ListWrapper.first(keys).token);
       return `No provider for ${first}!${constructResolvingPath(keys)}`;
     });
   }
 }
 
-/**
- * Thrown when trying to retrieve an async {@link Binding} using the sync API.
- *
- * ## Example
- *
- * ```javascript
- * var injector = Injector.resolveAndCreate([
- *   bind(Number).toAsyncFactory(() => {
- *     return new Promise((resolve) => resolve(1 + 2));
- *   }),
- *   bind(String).toFactory((v) => { return "Value: " + v; }, [String])
- * ]);
- *
- * injector.asyncGet(String).then((v) => expect(v).toBe('Value: 3'));
- * expect(() => {
- *   injector.get(String);
- * }).toThrowError(AsycBindingError);
- * ```
- *
- * The above example throws because `String` depends on `Number` which is async. If any binding in
- * the dependency graph is async then the graph can only be retrieved using the `asyncGet` API.
- */
-export class AsyncBindingError extends AbstractBindingError {
-  // TODO(tbosch): Can't do key:Key as this results in a circular dependency!
-  constructor(key) {
-    super(key, function(keys: List<any>) {
-      var first = stringify(ListWrapper.first(keys).token);
-      return `Cannot instantiate ${first} synchronously. It is provided as a promise!${constructResolvingPath(keys)}`;
-    });
-  }
-}
-
 /**
  * Thrown when dependencies form a cycle.
  *
@@ -113,9 +87,8 @@ export class AsyncBindingError extends AbstractBindingError {
  * Retrieving `A` or `B` throws a `CyclicDependencyError` as the graph above cannot be constructed.
  */
 export class CyclicDependencyError extends AbstractBindingError {
-  // TODO(tbosch): Can't do key:Key as this results in a circular dependency!
-  constructor(key) {
-    super(key, function(keys: List<any>) {
+  constructor(injector: Injector, key: Key) {
+    super(injector, key, function(keys: List<any>) {
       return `Cannot instantiate cyclic dependency!${constructResolvingPath(keys)}`;
     });
   }
@@ -128,14 +101,13 @@ export class CyclicDependencyError extends AbstractBindingError {
  * this object to be instantiated.
  */
 export class InstantiationError extends AbstractBindingError {
-  causeKey;
-
-  // TODO(tbosch): Can't do key:Key as this results in a circular dependency!
-  constructor(originalException, originalStack, key) {
-    super(key, function(keys: List<any>) {
+  causeKey: Key;
+  constructor(injector: Injector, originalException, originalStack, key: Key) {
+    super(injector, key, function(keys: List<any>) {
       var first = stringify(ListWrapper.first(keys).token);
       return `Error during instantiation of ${first}!${constructResolvingPath(keys)}.` +
-             ` ORIGINAL ERROR: ${originalException}` + `\n\n ORIGINAL STACK: ${originalStack}`;
+             `\n\n ORIGINAL ERROR: ${originalException}` +
+             `\n\n ORIGINAL STACK: ${originalStack} \n`;
     }, originalException, originalStack);
 
     this.causeKey = key;

modules/angular2/src/di/injector.ts

@@ -5,7 +5,6 @@ import {ResolvedBinding, Binding, Dependency, BindingBuilder, bind} from './bind
 import {
   AbstractBindingError,
   NoBindingError,
-  AsyncBindingError,
   CyclicDependencyError,
   InstantiationError,
   InvalidBindingError,
@@ -174,8 +173,10 @@ export class ProtoInjectorDynamicStrategy implements ProtoInjectorStrategy {
 
 export class ProtoInjector {
   _strategy: ProtoInjectorStrategy;
+  numberOfBindings: number;
 
   constructor(bwv: BindingWithVisibility[]) {
+    this.numberOfBindings = bwv.length;
     this._strategy = bwv.length > _MAX_CONSTRUCTION_COUNTER ?
                          new ProtoInjectorDynamicStrategy(this, bwv) :
                          new ProtoInjectorInlineStrategy(this, bwv);
@@ -469,10 +470,18 @@ export class Injector {
   _constructionCounter: number = 0;
 
   constructor(public _proto: ProtoInjector, public _parent: Injector = null,
-              private _depProvider: DependencyProvider = null) {
+              private _depProvider: DependencyProvider = null,
+              private _debugContext: Function = null) {
     this._strategy = _proto._strategy.createInjectorStrategy(this);
   }
 
+  /**
+   * Returns debug information about the injector.
+   *
+   * This information is included into exceptions thrown by the injector.
+   */
+  debugContext(): any { return this._debugContext(); }
+
   /**
    * Retrieves an instance from the injector.
    *
@@ -550,7 +559,7 @@ export class Injector {
 
   _new(binding: ResolvedBinding, visibility: number): any {
     if (this._constructionCounter++ > this._strategy.getMaxNumberOfObjects()) {
-      throw new CyclicDependencyError(binding.key);
+      throw new CyclicDependencyError(this, binding.key);
     }
 
     var factory = binding.factory;
@@ -580,7 +589,9 @@ export class Injector {
       d18 = length > 18 ? this._getByDependency(binding, deps[18], visibility) : null;
       d19 = length > 19 ? this._getByDependency(binding, deps[19], visibility) : null;
     } catch (e) {
-      if (e instanceof AbstractBindingError) e.addKey(binding.key);
+      if (e instanceof AbstractBindingError) {
+        e.addKey(this, binding.key);
+      }
       throw e;
     }
 
@@ -655,7 +666,7 @@ export class Injector {
           break;
       }
     } catch (e) {
-      throw new InstantiationError(e, e.stack, binding.key);
+      throw new InstantiationError(this, e, e.stack, binding.key);
     }
     return obj;
   }
@@ -693,7 +704,7 @@ export class Injector {
     if (optional) {
       return null;
     } else {
-      throw new NoBindingError(key);
+      throw new NoBindingError(this, key);
     }
   }
 
@@ -751,6 +762,12 @@ export class Injector {
 
     return this._throwOrNull(key, optional);
   }
+
+  get displayName(): string {
+    return `Injector(bindings: [${_mapBindings(this, b => ` "${b.key.displayName}" `).join(", ")}])`;
+  }
+
+  toString(): string { return this.displayName; }
 }
 
 var INJECTOR_KEY = Key.get(Injector);
@@ -795,3 +812,11 @@ function _flattenBindings(bindings: List<ResolvedBinding | List<any>>,
   });
   return res;
 }
+
+function _mapBindings(injector: Injector, fn: Function): any[] {
+  var res = [];
+  for (var i = 0; i < injector._proto.numberOfBindings; ++i) {
+    res.push(fn(injector._proto.getBindingAtIndex(i)));
+  }
+  return res;
+}

modules/angular2/test/core/compiler/integration_spec.ts

@@ -1154,6 +1154,22 @@ export function main() {
            });
          }));
 
+      it('should provide an error context when an error happens in the DI',
+         inject([TestComponentBuilder, AsyncTestCompleter], (tcb: TestComponentBuilder, async) => {
+
+           tcb = tcb.overrideView(MyComp, new viewAnn.View({
+             directives: [DirectiveThrowingAnError],
+             template: `<directive-throwing-error></<directive-throwing-error>`
+           }));
+
+           PromiseWrapper.catchError(tcb.createAsync(MyComp), (e) => {
+             expect(DOM.nodeName(e.context.element).toUpperCase())
+                 .toEqual("DIRECTIVE-THROWING-ERROR");
+             async.done();
+             return null;
+           });
+         }));
+
       if (!IS_DARTIUM) {
         it('should report a meaningful error when a directive is undefined',
            inject([TestComponentBuilder, AsyncTestCompleter], (tcb: TestComponentBuilder,
@@ -1870,3 +1886,11 @@ class OtherDuplicateDir {
     DOM.setText(elRef.nativeElement, DOM.getText(elRef.nativeElement) + 'othernoduplicate');
   }
 }
+
+@Directive({selector: 'directive-throwing-error'})
+class DirectiveThrowingAnError {
+  constructor() {
+    throw new BaseException("BOOM");
+    ;
+  }
+}

modules/angular2/test/di/injector_spec.ts

@@ -292,7 +292,12 @@ export function main() {
       });
 
       it('should show the full path when error happens in a constructor', () => {
-        var injector = createInjector([Car, bind(Engine).toClass(BrokenEngine)]);
+        var bindings = Injector.resolve([Car, bind(Engine).toClass(BrokenEngine)]);
+        var proto = new ProtoInjector([
+          new BindingWithVisibility(bindings[0], PUBLIC),
+          new BindingWithVisibility(bindings[1], PUBLIC)
+        ]);
+        var injector = new Injector(proto, null, null);
 
         try {
           injector.get(Car);
@@ -305,6 +310,24 @@ export function main() {
         }
       });
 
+      it('should provide context when throwing an exception ', () => {
+        var engineBinding = Injector.resolve([bind(Engine).toClass(BrokenEngine)])[0];
+        var protoParent = new ProtoInjector([new BindingWithVisibility(engineBinding, PUBLIC)]);
+
+        var carBinding = Injector.resolve([Car])[0];
+        var protoChild = new ProtoInjector([new BindingWithVisibility(carBinding, PUBLIC)]);
+
+        var parent = new Injector(protoParent, null, null, () => "parentContext");
+        var child = new Injector(protoChild, parent, null, () => "childContext");
+
+        try {
+          child.get(Car);
+          throw "Must throw";
+        } catch (e) {
+          expect(e.context).toEqual("childContext");
+        }
+      });
+
       it('should instantiate an object after a failed attempt', () => {
         var isBroken = true;
 
@@ -545,5 +568,12 @@ export function main() {
         expect(binding.dependencies[0].properties).toEqual([new CustomDependencyMetadata()]);
       });
     });
+
+    describe("displayName", () => {
+      it("should work", () => {
+        expect(Injector.resolveAndCreate([Engine, BrokenEngine]).displayName)
+            .toEqual('Injector(bindings: [ "Engine" ,  "BrokenEngine" ])');
+      });
+    });
   });
 }