fix(di): do not use exceptions to detect if reflection is enabled

Author: vsavkin

modules/angular2/src/di/binding.ts

@@ -450,16 +450,15 @@ function _extractToken(typeOrFunc, annotations /*List<any> | any*/,
     throw new NoAnnotationError(typeOrFunc, params);
   }
 }
-
 function _defaulVisiblity(typeOrFunc) {
-  try {
-    if (!(typeOrFunc instanceof Type)) return unbounded;
-    var f =
-        ListWrapper.filter(reflector.annotations(typeOrFunc), s => s instanceof InjectableMetadata);
-    return f.length === 0 ? unbounded : f[0].visibility;
-  } catch (e) {
-    return unbounded;
-  }
+  if (!(typeOrFunc instanceof Type)) return unbounded;
+
+  // TODO: vsavkin revisit this after clarifying lookup rules
+  if (!reflector.isReflectionEnabled()) return unbounded;
+
+  var f =
+      ListWrapper.filter(reflector.annotations(typeOrFunc), s => s instanceof InjectableMetadata);
+  return f.length === 0 ? unbounded : f[0].visibility;
 }
 
 function _createDependency(token, optional, visibility, depProps): Dependency {

modules/angular2/src/reflection/platform_reflection_capabilities.ts

@@ -3,6 +3,7 @@ import {GetterFn, SetterFn, MethodFn} from './types';
 import {List} from 'angular2/src/facade/collection';
 
 export interface PlatformReflectionCapabilities {
+  isReflectionEnabled(): boolean;
   factory(type: Type): Function;
   interfaces(type: Type): List<any>;
   parameters(type: Type): List<List<any>>;

modules/angular2/src/reflection/reflection.dart

@@ -7,6 +7,10 @@ import 'platform_reflection_capabilities.dart';
 import 'package:angular2/src/facade/lang.dart';
 
 class NoReflectionCapabilities implements PlatformReflectionCapabilities {
+  bool isReflectionEnabled() {
+    return false;
+  }
+
   Function factory(Type type) {
     throw "Cannot find reflection information on ${stringify(type)}";
   }

modules/angular2/src/reflection/reflection_capabilities.dart

@@ -8,6 +8,10 @@ import 'platform_reflection_capabilities.dart';
 class ReflectionCapabilities implements PlatformReflectionCapabilities {
   ReflectionCapabilities([metadataReader]) {}
 
+  bool isReflectionEnabled() {
+    return true;
+  }
+
   Function factory(Type type) {
     ClassMirror classMirror = reflectType(type);
     MethodMirror ctor = classMirror.declarations[classMirror.simpleName];

modules/angular2/src/reflection/reflection_capabilities.ts

@@ -15,6 +15,8 @@ export class ReflectionCapabilities implements PlatformReflectionCapabilities {
 
   constructor(reflect?: any) { this._reflect = isPresent(reflect) ? reflect : global.Reflect; }
 
+  isReflectionEnabled(): boolean { return true; }
+
   factory(t: Type): Function {
     switch (t.length) {
       case 0:

modules/angular2/src/reflection/reflector.ts

@@ -27,6 +27,8 @@ export class Reflector {
     this.reflectionCapabilities = reflectionCapabilities;
   }
 
+  isReflectionEnabled(): boolean { return this.reflectionCapabilities.isReflectionEnabled(); }
+
   registerFunction(func: Function, funcInfo: StringMap<string, any>): void {
     this._injectableInfo.set(func, funcInfo);
   }

modules/angular2/src/transform/template_compiler/reflection_capabilities.dart

@@ -10,6 +10,8 @@ class NullReflectionCapabilities implements ReflectionCapabilities {
 
   _notImplemented(String name) => throw 'Not implemented: $name';
 
+  bool isReflectionEnabled() { return false; }
+
   Function factory(Type type) => _notImplemented('factory');
 
   List<List> parameters(typeOrFunc) => _notImplemented('parameters');