fix(compiler): support empty array and map literals.

This was broken after 152a117d5c27e56d1b32d69df2f69d34b94c0760

Fixes #8336

modules/angular2/src/compiler/identifiers.ts

@@ -7,6 +7,8 @@ import {
   interpolate,
   checkBinding,
   castByValue,
+  EMPTY_ARRAY,
+  EMPTY_MAP,
   pureProxy1,
   pureProxy2,
   pureProxy3,
@@ -72,6 +74,8 @@ var impDevModeEqual = devModeEqual;
 var impInterpolate = interpolate;
 var impCheckBinding = checkBinding;
 var impCastByValue = castByValue;
+var impEMPTY_ARRAY = EMPTY_ARRAY;
+var impEMPTY_MAP = EMPTY_MAP;
 
 export class Identifiers {
   static ViewUtils = new CompileIdentifierMetadata({
@@ -179,6 +183,11 @@ export class Identifiers {
       {name: 'interpolate', moduleUrl: VIEW_UTILS_MODULE_URL, runtime: impInterpolate});
   static castByValue = new CompileIdentifierMetadata(
       {name: 'castByValue', moduleUrl: VIEW_UTILS_MODULE_URL, runtime: impCastByValue});
+  static EMPTY_ARRAY = new CompileIdentifierMetadata(
+      {name: 'EMPTY_ARRAY', moduleUrl: VIEW_UTILS_MODULE_URL, runtime: impEMPTY_ARRAY});
+  static EMPTY_MAP = new CompileIdentifierMetadata(
+      {name: 'EMPTY_MAP', moduleUrl: VIEW_UTILS_MODULE_URL, runtime: impEMPTY_MAP});
+
   static pureProxies = [
     null,
     new CompileIdentifierMetadata(

modules/angular2/src/compiler/view_compiler/compile_view.ts

@@ -24,6 +24,7 @@ import {
 } from './util';
 import {CompilerConfig} from '../config';
 import {CompileBinding} from './compile_binding';
+import {Identifiers} from '../identifiers';
 
 export class CompileView implements NameResolver {
   public viewType: ViewType;
@@ -155,6 +156,9 @@ export class CompileView implements NameResolver {
   }
 
   createLiteralArray(values: o.Expression[]): o.Expression {
+    if (values.length === 0) {
+      return o.importExpr(Identifiers.EMPTY_ARRAY);
+    }
     var proxyExpr = o.THIS_EXPR.prop(`_arr_${this.literalArrayCount++}`);
     var proxyParams: o.FnParam[] = [];
     var proxyReturnEntries: o.Expression[] = [];
@@ -169,6 +173,9 @@ export class CompileView implements NameResolver {
   }
 
   createLiteralMap(entries: Array<Array<string | o.Expression>>): o.Expression {
+    if (entries.length === 0) {
+      return o.importExpr(Identifiers.EMPTY_MAP);
+    }
     var proxyExpr = o.THIS_EXPR.prop(`_map_${this.literalMapCount++}`);
     var proxyParams: o.FnParam[] = [];
     var proxyReturnEntries: Array<Array<string | o.Expression>> = [];

modules/angular2/src/core/linker/view_utils.ts

@@ -156,6 +156,9 @@ export function castByValue<T>(input: any, value: T): T {
   return <T>input;
 }
 
+export const EMPTY_ARRAY = CONST_EXPR([]);
+export const EMPTY_MAP = CONST_EXPR({});
+
 export function pureProxy1<P0, R>(fn: (p0: P0) => R): (p0: P0) => R {
   var result: R;
   var v0;

modules/angular2/test/core/linker/change_detection_integration_spec.ts

@@ -371,6 +371,12 @@ export function main() {
            expect(renderLog.loggedValues).toEqual([[1, 2]]);
          }));
 
+      it('should support empty literal array', fakeAsync(() => {
+           var ctx = _bindSimpleValue('[]');
+           ctx.detectChanges(false);
+           expect(renderLog.loggedValues).toEqual([[]]);
+         }));
+
       it('should support literal array made of expressions', fakeAsync(() => {
            var ctx = _bindSimpleValue('[1, a]', TestData);
            ctx.componentInstance.a = 2;
@@ -395,6 +401,12 @@ export function main() {
            expect(renderLog.loggedValues[0]['z']).toEqual(1);
          }));
 
+      it('should support empty literal map', fakeAsync(() => {
+           var ctx = _bindSimpleValue('{}');
+           ctx.detectChanges(false);
+           expect(renderLog.loggedValues).toEqual([{}]);
+         }));
+
       it('should support literal maps made of expressions', fakeAsync(() => {
            var ctx = _bindSimpleValue('{z: a}');
            ctx.componentInstance.a = 1;