feat(change detect): Throw on attempts to use dehydrated detector

- Modify change detectors to `throw` when attempting to detect changes
  on a dehydrated detector.
- Modify `DynamicChagneDetector` to use `null` for the `context` of a
  dehydrated detector.

modules/angular2/change_detection.ts

@@ -19,6 +19,7 @@ export {Parser} from './src/change_detection/parser/parser';
 export {Locals} from './src/change_detection/parser/locals';
 
 export {
+  DehydratedException,
   ExpressionChangedAfterItHasBeenChecked,
   ChangeDetectionError
 } from './src/change_detection/exceptions';

modules/angular2/src/change_detection/change_detection_jit_generator.dart

@@ -1,5 +1,11 @@
 library change_detectoin.change_detection_jit_generator;
 
+/// Placeholder JIT generator for Dart.
+/// Dart does not support `eval`, so JIT generation is not an option. Instead,
+/// the Dart transformer pre-generates these Change Detector classes and
+/// registers them with the system. See `PreGeneratedChangeDetection`,
+/// `PregenProtoChangeDetector`, and
+/// `src/transform/template_compiler/change_detector_codegen.dart` for details.
 class ChangeDetectorJITGenerator {
   ChangeDetectorJITGenerator(typeName, strategy, records, directiveMementos) {}
 

modules/angular2/src/change_detection/change_detection_jit_generator.ts

@@ -98,6 +98,9 @@ export class ChangeDetectorJITGenerator {
       ${this.typeName}.prototype = Object.create(${ABSTRACT_CHANGE_DETECTOR}.prototype);
 
       ${this.typeName}.prototype.detectChangesInRecords = function(throwOnChange) {
+        if (!this.hydrated()) {
+          ${UTIL}.throwDehydrated();
+        }
         ${this._genLocalDefinitions()}
         ${this._genChangeDefinitions()}
         var ${IS_CHANGED_LOCAL} = false;
@@ -131,7 +134,7 @@ export class ChangeDetectorJITGenerator {
       }
 
       ${this.typeName}.prototype.hydrated = function() {
-        return Boolean(${CONTEXT_ACCESSOR});
+        return ${CONTEXT_ACCESSOR} !== null;
       }
 
       return function(dispatcher, pipeRegistry) {

modules/angular2/src/change_detection/change_detection_util.ts

@@ -1,7 +1,7 @@
 import {isPresent, isBlank, BaseException, Type} from 'angular2/src/facade/lang';
 import {List, ListWrapper, MapWrapper, StringMapWrapper} from 'angular2/src/facade/collection';
 import {ProtoRecord} from './proto_record';
-import {ExpressionChangedAfterItHasBeenChecked} from './exceptions';
+import {DehydratedException, ExpressionChangedAfterItHasBeenChecked} from './exceptions';
 import {WrappedValue} from './pipes/pipe';
 import {CHECK_ALWAYS, CHECK_ONCE, CHECKED, DETACHED, ON_PUSH} from './constants';
 
@@ -127,6 +127,8 @@ export class ChangeDetectionUtil {
     throw new ExpressionChangedAfterItHasBeenChecked(proto, change);
   }
 
+  static throwDehydrated() { throw new DehydratedException(); }
+
   static changeDetectionMode(strategy: string) {
     return strategy == ON_PUSH ? CHECK_ONCE : CHECK_ALWAYS;
   }

modules/angular2/src/change_detection/dynamic_change_detector.ts

@@ -44,7 +44,8 @@ export class DynamicChangeDetector extends AbstractChangeDetector {
     this.prevContexts = ListWrapper.createFixedSize(protos.length + 1);
     this.changes = ListWrapper.createFixedSize(protos.length + 1);
 
-    ListWrapper.fill(this.values, uninitialized);
+    this.values[0] = null;
+    ListWrapper.fill(this.values, uninitialized, 1);
     ListWrapper.fill(this.pipes, null);
     ListWrapper.fill(this.prevContexts, uninitialized);
     ListWrapper.fill(this.changes, false);
@@ -60,7 +61,8 @@ export class DynamicChangeDetector extends AbstractChangeDetector {
 
   dehydrate() {
     this._destroyPipes();
-    ListWrapper.fill(this.values, uninitialized);
+    this.values[0] = null;
+    ListWrapper.fill(this.values, uninitialized, 1);
     ListWrapper.fill(this.changes, false);
     ListWrapper.fill(this.pipes, null);
     ListWrapper.fill(this.prevContexts, uninitialized);
@@ -75,9 +77,12 @@ export class DynamicChangeDetector extends AbstractChangeDetector {
     }
   }
 
-  hydrated(): boolean { return this.values[0] !== uninitialized; }
+  hydrated(): boolean { return this.values[0] !== null; }
 
   detectChangesInRecords(throwOnChange: boolean) {
+    if (!this.hydrated()) {
+      ChangeDetectionUtil.throwDehydrated();
+    }
     var protos: List<ProtoRecord> = this.protos;
 
     var changes = null;

modules/angular2/src/change_detection/exceptions.ts

@@ -27,4 +27,8 @@ export class ChangeDetectionError extends BaseException {
   }
 
   toString(): string { return this.message; }
-}
+}
+
+export class DehydratedException extends BaseException {
+  constructor() { super('Attempt to detect changes on a dehydrated detector.'); }
+}

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

@@ -113,6 +113,9 @@ class _CodegenState {
             this.$_DIRECTIVES_ACCESSOR) : super();
 
         void detectChangesInRecords(throwOnChange) {
+          if (!hydrated()) {
+            $_UTIL.throwDehydrated();
+          }
           ${_genLocalDefinitions()}
           ${_genChangeDefinitons()}
           var $_IS_CHANGED_LOCAL = false;
@@ -145,7 +148,7 @@ class _CodegenState {
           $_LOCALS_ACCESSOR = null;
         }
 
-        hydrated() => $_CONTEXT_ACCESSOR == null;
+        hydrated() => $_CONTEXT_ACCESSOR != null;
 
         static $_GEN_PREFIX.ProtoChangeDetector
             $PROTO_CHANGE_DETECTOR_FACTORY_METHOD(

modules/angular2/test/change_detection/change_detector_spec.ts

@@ -11,6 +11,7 @@ import {
 } from 'angular2/test_lib';
 
 import {
+  CONST_EXPR,
   isPresent,
   isBlank,
   isJsObject,
@@ -21,6 +22,7 @@ import {List, ListWrapper, MapWrapper, StringMapWrapper} from 'angular2/src/faca
 
 import {
   ChangeDispatcher,
+  DehydratedException,
   DynamicChangeDetector,
   ChangeDetectionError,
   BindingRecord,
@@ -47,6 +49,7 @@ import {
 import {getDefinition} from './simple_watch_config';
 import {getFactoryById} from './generated/simple_watch_classes';
 
+const _DEFAULT_CONTEXT = CONST_EXPR(new Object());
 
 export function main() {
   // These tests also run against pre-generated Dart Change Detectors. We will move tests up from
@@ -72,7 +75,7 @@ export function main() {
         }
       }
 
-      function _bindSimpleValue(expression: string, context = null) {
+      function _bindSimpleValue(expression: string, context = _DEFAULT_CONTEXT) {
         var dispatcher = new TestDispatcher();
         var testDef = getDefinition(expression);
         var protoCd = _getProtoChangeDetector(testDef.cdDef);
@@ -297,7 +300,7 @@ export function main() {
 
           function dirs(directives: List<any>) { return new FakeDirectives(directives, []); }
 
-          function createChangeDetector(propName: string, exp: string, context = null,
+          function createChangeDetector(propName: string, exp: string, context = _DEFAULT_CONTEXT,
                                         registry = null) {
             var dispatcher = new TestDispatcher();
 
@@ -444,7 +447,7 @@ export function main() {
 
                   var cd = pcd.instantiate(dispatcher);
 
-                  cd.hydrate(null, null, dirs([directive1]));
+                  cd.hydrate(_DEFAULT_CONTEXT, null, dirs([directive1]));
 
                   cd.detectChanges();
 
@@ -465,7 +468,7 @@ export function main() {
 
                     var cd = pcd.instantiate(dispatcher);
 
-                    cd.hydrate(null, null, dirs([directive1, directive2]));
+                    cd.hydrate(_DEFAULT_CONTEXT, null, dirs([directive1, directive2]));
 
                     cd.detectChanges();
 
@@ -482,7 +485,7 @@ export function main() {
 
                     var cd = pcd.instantiate(dispatcher);
 
-                    cd.hydrate(null, null, dirs([directive1]));
+                    cd.hydrate(_DEFAULT_CONTEXT, null, dirs([directive1]));
 
                     cd.detectChanges();
 
@@ -502,7 +505,7 @@ export function main() {
 
                     var cd = pcd.instantiate(dispatcher);
 
-                    cd.hydrate(null, null, dirs([directive1]));
+                    cd.hydrate(_DEFAULT_CONTEXT, null, dirs([directive1]));
 
                     cd.checkNoChanges();
 
@@ -518,7 +521,7 @@ export function main() {
 
                     var cd = pcd.instantiate(dispatcher);
 
-                    cd.hydrate(null, null, dirs([directive1]));
+                    cd.hydrate(_DEFAULT_CONTEXT, null, dirs([directive1]));
 
                     cd.detectChanges();
 
@@ -538,7 +541,7 @@ export function main() {
 
                     var cd = pcd.instantiate(dispatcher);
 
-                    cd.hydrate(null, null, dirs([directive1]));
+                    cd.hydrate(_DEFAULT_CONTEXT, null, dirs([directive1]));
 
                     cd.checkNoChanges();
 
@@ -551,7 +554,7 @@ export function main() {
                     var pcd = createProtoChangeDetector([], [], [dirRecord1, dirRecord2]);
 
                     var cd = pcd.instantiate(dispatcher);
-                    cd.hydrate(null, null, dirs([directive1, directive2]));
+                    cd.hydrate(_DEFAULT_CONTEXT, null, dirs([directive1, directive2]));
 
                     cd.detectChanges();
 
@@ -582,7 +585,7 @@ export function main() {
 
                     var cd = pcd.instantiate(dispatcher);
 
-                    cd.hydrate(null, null, dirs([directive1]));
+                    cd.hydrate(_DEFAULT_CONTEXT, null, dirs([directive1]));
 
                     cd.detectChanges();
 
@@ -599,7 +602,7 @@ export function main() {
                        td1 = new TestDirective(() => ListWrapper.push(onChangesDoneCalls, td1));
                        var td2;
                        td2 = new TestDirective(() => ListWrapper.push(onChangesDoneCalls, td2));
-                       cd.hydrate(null, null, dirs([td1, td2]));
+                       cd.hydrate(_DEFAULT_CONTEXT, null, dirs([td1, td2]));
 
                        cd.detectChanges();
 
@@ -620,8 +623,8 @@ export function main() {
                     var parentDirective =
                         new TestDirective(() => { expect(directiveInShadowDom.a).toBe(null); });
 
-                    parent.hydrate(null, null, dirs([parentDirective]));
+                    parent.hydrate(_DEFAULT_CONTEXT, null, dirs([parentDirective]));
-                    child.hydrate(null, null, dirs([directiveInShadowDom]));
+                    child.hydrate(_DEFAULT_CONTEXT, null, dirs([directiveInShadowDom]));
 
                     parent.detectChanges();
                   });
@@ -641,7 +644,7 @@ export function main() {
                     [BindingRecord.createForHostProperty(index, ast("a"), "prop")], null,
                     [dirRecord]);
                 var cd = pcd.instantiate(dispatcher);
-                cd.hydrate(null, null, dirs([directive]));
+                cd.hydrate(_DEFAULT_CONTEXT, null, dirs([directive]));
 
                 cd.detectChanges();
 
@@ -688,7 +691,7 @@ export function main() {
                 var cd = pcd.instantiate(
                     new TestDispatcher(),
                     [BindingRecord.createForElement(ast("invalidProp"), 0, "a")], null, []);
-                cd.hydrate(null, null);
+                cd.hydrate(_DEFAULT_CONTEXT, null);
 
                 try {
                   cd.detectChanges();
@@ -747,7 +750,7 @@ export function main() {
 
                  expect(cd.mode).toEqual(null);
 
-                 cd.hydrate(null, null, null);
+                 cd.hydrate(_DEFAULT_CONTEXT, null, null);
 
                  expect(cd.mode).toEqual(CHECK_ALWAYS);
                });
@@ -755,7 +758,7 @@ export function main() {
             it("should set the mode to CHECK_ONCE when the push change detection is used", () => {
               var proto = createProtoChangeDetector([], [], [], null, ON_PUSH);
               var cd = proto.instantiate(null);
-              cd.hydrate(null, null, null);
+              cd.hydrate(_DEFAULT_CONTEXT, null, null);
 
               expect(cd.mode).toEqual(CHECK_ONCE);
             });
@@ -765,6 +768,7 @@ export function main() {
               var cd = c["changeDetector"];
               var dispatcher = c["dispatcher"];
 
+              cd.hydrate(_DEFAULT_CONTEXT, null, null);
               cd.mode = DETACHED;
               cd.detectChanges();
 
@@ -776,6 +780,7 @@ export function main() {
               var cd = c["changeDetector"];
               var dispatcher = c["dispatcher"];
 
+              cd.hydrate(_DEFAULT_CONTEXT, null, null);
               cd.mode = CHECKED;
               cd.detectChanges();
 
@@ -784,6 +789,7 @@ export function main() {
 
             it("should change CHECK_ONCE to CHECKED", () => {
               var cd = createProtoChangeDetector([]).instantiate(null);
+              cd.hydrate(_DEFAULT_CONTEXT, null, null);
               cd.mode = CHECK_ONCE;
 
               cd.detectChanges();
@@ -793,6 +799,7 @@ export function main() {
 
             it("should not change the CHECK_ALWAYS", () => {
               var cd = createProtoChangeDetector([]).instantiate(null);
+              cd.hydrate(_DEFAULT_CONTEXT, null, null);
               cd.mode = CHECK_ALWAYS;
 
               cd.detectChanges();
@@ -809,7 +816,7 @@ export function main() {
               beforeEach(() => {
                 var proto = createProtoChangeDetector([], [], [], null, ON_PUSH);
                 checkedDetector = proto.instantiate(null);
-                checkedDetector.hydrate(null, null, null);
+                checkedDetector.hydrate(_DEFAULT_CONTEXT, null, null);
                 checkedDetector.mode = CHECKED;
 
                 // this directive is a component with ON_PUSH change detection
@@ -829,7 +836,7 @@ export function main() {
                                                       [dirRecordWithOnPush]);
 
                 var cd = proto.instantiate(null);
-                cd.hydrate(null, null, directives);
+                cd.hydrate(_DEFAULT_CONTEXT, null, directives);
 
                 expect(checkedDetector.mode).toEqual(CHECKED);
 
@@ -898,6 +905,21 @@ export function main() {
 
               expect(pipe.destroyCalled).toBe(true);
             });
+
+            it("should throw when detectChanges is called on a dehydrated detector", () => {
+              var context = new Person('Bob');
+              var c = createChangeDetector("propName", "name", context);
+              var cd = c["changeDetector"];
+              var log = c["dispatcher"].log;
+
+              cd.detectChanges();
+              expect(log).toEqual(["propName=Bob"]);
+
+              cd.dehydrate();
+              var dehydratedException = new DehydratedException();
+              expect(() => {cd.detectChanges()}).toThrowError(dehydratedException.toString());
+              expect(log).toEqual(["propName=Bob"]);
+            });
           });
 
           describe("pipes", () => {
@@ -1098,13 +1120,8 @@ class TestDirective {
 }
 
 class Person {
-  name: string;
   age: number;
-  address: Address;
+  constructor(public name: string, public address: Address = null) {}
-  constructor(name: string, address: Address = null) {
-    this.name = name;
-    this.address = address;
-  }
 
   sayHi(m) { return `Hi, ${m}`; }
 

modules/angular2/test/transform/integration/two_annotations_files/expected/bar.ng_deps.dart

@@ -34,6 +34,9 @@ class _MyComponent_ChangeDetector0 extends _gen.AbstractChangeDetector {
       : super();
 
   void detectChangesInRecords(throwOnChange) {
+    if (!hydrated()) {
+      _gen.ChangeDetectionUtil.throwDehydrated();
+    }
     var context = null;
     var change_context = false;
     var isChanged = false;
@@ -56,7 +59,7 @@ class _MyComponent_ChangeDetector0 extends _gen.AbstractChangeDetector {
     _locals = null;
   }
 
-  hydrated() => _context == null;
+  hydrated() => _context != null;
 
   static _gen.ProtoChangeDetector newProtoChangeDetector(
       _gen.PipeRegistry registry, _gen.ChangeDetectorDefinition def) {

modules/benchmarks/src/change_detection/change_detection_benchmark.ts

@@ -280,6 +280,7 @@ function setUpChangeDetection(changeDetection: ChangeDetection, iterations, obje
       new ChangeDetectorDefinition("proto", null, [], bindings, [directiveRecord]));
 
   var targetObj = new Obj();
+  parentCd.hydrate(object, null, new FakeDirectives(targetObj));
   for (var i = 0; i < iterations; ++i) {
     var cd = proto.instantiate(dispatcher);
     cd.hydrate(object, null, new FakeDirectives(targetObj));