[FIX] observer: newly observed object/arrays have higher rev

Some people apparently believe that the framework should magically
solves all problems from the programmers, shielding him from thinking.

It is not possible, and maybe a bad idea, because it will only delay the
inevitable...  If one does weird stuff without knowing what is going on,
someone will get hurt.

However, in this specific case, something can be done.

closes #104

src/observer.ts

@@ -39,6 +39,7 @@ for (let method of methodsToPatch) {
     if (!this.__observer__.allowMutations) {
       throw new Error(`Array cannot be changed here")`);
     }
+    this.__observer__.rev++;
     this.__observer__.notifyChange();
     this.__owl__.rev++;
     let parent = this;
@@ -74,7 +75,6 @@ export class Observer {
 
   notifyCB() {}
   notifyChange() {
-    this.rev++;
     this.dirty = true;
     Promise.resolve().then(() => {
       if (this.dirty) {
@@ -105,6 +105,7 @@ export class Observer {
   }
 
   set(target: any, key: number | string, value: any) {
+    this.rev++;
     this._addProp(target, key, value);
     target.__owl__.rev++;
     this.notifyChange();
@@ -112,7 +113,7 @@ export class Observer {
 
   _observeObj<T extends { __owl__?: any }>(obj: T, parent?: any) {
     const keys = Object.keys(obj);
-    obj.__owl__ = { rev: 1, deepRev: 1, parent };
+    obj.__owl__ = { rev: this.rev, deepRev: this.rev, parent };
     Object.defineProperty(obj, "__owl__", { enumerable: false });
     for (let key of keys) {
       this._addProp(obj, key, obj[key]);
@@ -120,7 +121,7 @@ export class Observer {
   }
 
   _observeArr(arr: Array<any>, parent?: any) {
-    (<any>arr).__owl__ = { rev: 1, deepRev: 1, parent };
+    (<any>arr).__owl__ = { rev: this.rev, deepRev: this.rev, parent };
     Object.defineProperty(arr, "__owl__", { enumerable: false });
     (<any>arr).__proto__ = Object.create(ModifiedArrayProto);
     (<any>arr).__proto__.__observer__ = this;
@@ -142,6 +143,7 @@ export class Observer {
       },
       set(newVal) {
         if (newVal !== value) {
+          self.rev++;
           if (!self.allowMutations) {
             throw new Error(
               `Observed state cannot be changed here! (key: "${key}", val: "${newVal}")`

tests/observer.test.ts

@@ -126,12 +126,12 @@ describe("observer", () => {
     arr.push({ kriek: 5 });
     expect(observer.rev).toBe(2);
     expect(arr.__owl__.rev).toBe(2);
-    expect(arr[0].__owl__.rev).toBe(1);
+    expect(arr[0].__owl__.rev).toBe(2);
 
     arr[0].kriek = 6;
     expect(observer.rev).toBe(3);
     expect(arr.__owl__.rev).toBe(2);
-    expect(arr[0].__owl__.rev).toBe(2);
+    expect(arr[0].__owl__.rev).toBe(3);
   });
 
   test("properly observe arrays in object", () => {
@@ -180,12 +180,14 @@ describe("observer", () => {
     obj.a = { b: 2 };
     expect(observer.rev).toBe(2);
     expect(obj.__owl__.rev).toBe(2);
-    expect(obj.a.__owl__.rev).toBe(1);
+
+    // we start at 2 because it is the new observer rev number
+    expect(obj.a.__owl__.rev).toBe(2);
 
     obj.a.b = 3;
     expect(observer.rev).toBe(3);
     expect(obj.__owl__.rev).toBe(2);
-    expect(obj.a.__owl__.rev).toBe(2);
+    expect(obj.a.__owl__.rev).toBe(3);
   });
 
   test("deep observe misc changes", () => {