fix: Improve error message on missing dependency

modules/angular2/src/di/annotations_impl.ts

@@ -1,4 +1,4 @@
-import {CONST} from "angular2/src/facade/lang";
+import {CONST, stringify} from "angular2/src/facade/lang";
 
 /**
  * A parameter annotation that specifies a dependency.
@@ -15,6 +15,7 @@ import {CONST} from "angular2/src/facade/lang";
 @CONST()
 export class Inject {
   constructor(public token) {}
+  toString() { return `@Inject(${stringify(this.token)})`; }
 }
 
 /**
@@ -33,6 +34,7 @@ export class Inject {
 @CONST()
 export class InjectPromise {
   constructor(public token) {}
+  toString() { return `@InjectPromise(${stringify(this.token)})`; }
 }
 
 /**
@@ -51,6 +53,7 @@ export class InjectPromise {
 @CONST()
 export class InjectLazy {
   constructor(public token) {}
+  toString() { return `@InjectLazy(${stringify(this.token)})`; }
 }
 
 /**
@@ -69,6 +72,7 @@ export class InjectLazy {
  */
 @CONST()
 export class Optional {
+  toString() { return `@Optional()`; }
 }
 
 /**

modules/angular2/src/di/binding.ts

@@ -437,22 +437,27 @@ export class BindingBuilder {
   }
 }
 
-function _constructDependencies(factoryFunction: Function, dependencies: List<any>) {
-  return isBlank(dependencies) ?
-             _dependenciesFor(factoryFunction) :
-             ListWrapper.map(dependencies, (t) => _extractToken(factoryFunction, t));
+function _constructDependencies(factoryFunction: Function,
+                                dependencies: List<any>): List<Dependency> {
+  if (isBlank(dependencies)) {
+    return _dependenciesFor(factoryFunction);
+  } else {
+    var params: List<List<any>> = ListWrapper.map(dependencies, (t) => [t]);
+    return ListWrapper.map(dependencies, (t) => _extractToken(factoryFunction, t, params));
+  }
 }
 
-function _dependenciesFor(typeOrFunc): List<any> {
+function _dependenciesFor(typeOrFunc): List<Dependency> {
   var params = reflector.parameters(typeOrFunc);
   if (isBlank(params)) return [];
   if (ListWrapper.any(params, (p) => isBlank(p))) {
-    throw new NoAnnotationError(typeOrFunc);
+    throw new NoAnnotationError(typeOrFunc, params);
   }
-  return ListWrapper.map(params, (p) => _extractToken(typeOrFunc, p));
+  return ListWrapper.map(params, (p: List<any>) => _extractToken(typeOrFunc, p, params));
 }
 
-function _extractToken(typeOrFunc, annotations) {
+function _extractToken(typeOrFunc, annotations /*List<any> | any*/,
+                       params: List<List<any>>): Dependency {
   var depProps = [];
   var token = null;
   var optional = false;
@@ -496,7 +501,7 @@ function _extractToken(typeOrFunc, annotations) {
   if (isPresent(token)) {
     return _createDependency(token, asPromise, lazy, optional, depProps);
   } else {
-    throw new NoAnnotationError(typeOrFunc);
+    throw new NoAnnotationError(typeOrFunc, params);
   }
 }
 

modules/angular2/src/di/exceptions.ts

@@ -1,5 +1,5 @@
 import {ListWrapper, List} from 'angular2/src/facade/collection';
-import {stringify, BaseException} from 'angular2/src/facade/lang';
+import {stringify, BaseException, isBlank} from 'angular2/src/facade/lang';
 
 function findFirstClosedCycle(keys: List<any>): List<any> {
   var res = [];
@@ -179,9 +179,19 @@ export class InvalidBindingError extends BaseException {
 export class NoAnnotationError extends BaseException {
   name: string;
   message: string;
-  constructor(typeOrFunc) {
+  constructor(typeOrFunc, params: List<List<any>>) {
     super();
-    this.message = "Cannot resolve all parameters for " + stringify(typeOrFunc) + ". " +
+    var signature = ListWrapper.create();
+    for (var i = 0, ii = params.length; i < ii; i++) {
+      var parameter = params[i];
+      if (isBlank(parameter) || parameter.length == 0) {
+        ListWrapper.push(signature, '?');
+      } else {
+        ListWrapper.push(signature, ListWrapper.map(parameter, stringify).join(' '));
+      }
+    }
+    this.message = "Cannot resolve all parameters for " + stringify(typeOrFunc) + "(" +
+                   signature.join(', ') + "). " +
                    'Make sure they all have valid type or annotations.';
   }
 

modules/angular2/src/di/forward_ref.ts

@@ -1,4 +1,4 @@
-import {Type} from 'angular2/src/facade/lang';
+import {Type, stringify} from 'angular2/src/facade/lang';
 
 export interface ForwardRefFn { (): any; }
 
@@ -30,6 +30,7 @@ export interface ForwardRefFn { (): any; }
  */
 export function forwardRef(forwardRefFn: ForwardRefFn): Type {
   (<any>forwardRefFn).__forward_ref__ = forwardRef;
+  (<any>forwardRefFn).toString = function() { return stringify(this()); };
   return (<Type><any>forwardRefFn);
 }
 

modules/angular2/src/di/type_info.dart

@@ -0,0 +1,4 @@
+library angular2.di.type_info;
+
+// In dart always return empty, as we can get the co
+argsLength(Type type) => 0;