angular-docs-cn/modules/angular2/test/change_detection/pipes/keyvalue_changes_spec.ts

import {describe, it, iit, xit, expect, beforeEach, afterEach} from 'angular2/test_lib';
import {KeyValueChanges} from 'angular2/src/change_detection/pipes/keyvalue_changes';
import {NumberWrapper, isJsObject} from 'angular2/src/facade/lang';
import {MapWrapper} from 'angular2/src/facade/collection';
import {kvChangesAsString} from '../util';

// todo(vicb): Update the code & tests for object equality
export function main() {
  describe('keyvalue_changes', function() {
    describe('KeyValueChanges', function() {
      var changes;
      var m: Map<any, any>;

      beforeEach(() => {
        changes = new KeyValueChanges();
        m = new Map();
      });

      afterEach(() => { changes = null; });

      it('should detect additions', () => {
        changes.check(m);

        m.set('a', 1);
        changes.check(m);
        expect(changes.toString())
            .toEqual(kvChangesAsString({map: ['a[null->1]'], additions: ['a[null->1]']}));

        m.set('b', 2);
        changes.check(m);
        expect(changes.toString())
            .toEqual(kvChangesAsString(
                {map: ['a', 'b[null->2]'], previous: ['a'], additions: ['b[null->2]']}));
      });

      it('should handle changing key/values correctly', () => {
        m.set(1, 10);
        m.set(2, 20);
        changes.check(m);

        m.set(2, 10);
        m.set(1, 20);
        changes.check(m);
        expect(changes.toString())
            .toEqual(kvChangesAsString({
              map: ['1[10->20]', '2[20->10]'],
              previous: ['1[10->20]', '2[20->10]'],
              changes: ['1[10->20]', '2[20->10]']
            }));
      });

      it('should expose previous and current value', () => {
        var previous, current;

        m.set(1, 10);
        changes.check(m);

        m.set(1, 20);
        changes.check(m);

        changes.forEachChangedItem((record) => {
          previous = record.previousValue;
          current = record.currentValue;
        });

        expect(previous).toEqual(10);
        expect(current).toEqual(20);
      });

      it('should do basic map watching', () => {
        changes.check(m);

        m.set('a', 'A');
        changes.check(m);
        expect(changes.toString())
            .toEqual(kvChangesAsString({map: ['a[null->A]'], additions: ['a[null->A]']}));

        m.set('b', 'B');
        changes.check(m);
        expect(changes.toString())
            .toEqual(kvChangesAsString(
                {map: ['a', 'b[null->B]'], previous: ['a'], additions: ['b[null->B]']}));

        m.set('b', 'BB');
        m.set('d', 'D');
        changes.check(m);
        expect(changes.toString())
            .toEqual(kvChangesAsString({
              map: ['a', 'b[B->BB]', 'd[null->D]'],
              previous: ['a', 'b[B->BB]'],
              additions: ['d[null->D]'],
              changes: ['b[B->BB]']
            }));

        MapWrapper.delete(m, 'b');
        changes.check(m);
        expect(changes.toString())
            .toEqual(kvChangesAsString(
                {map: ['a', 'd'], previous: ['a', 'b[BB->null]', 'd'], removals: ['b[BB->null]']}));

        m.clear();
        changes.check(m);
        expect(changes.toString())
            .toEqual(kvChangesAsString(
                {previous: ['a[A->null]', 'd[D->null]'], removals: ['a[A->null]', 'd[D->null]']}));
      });

      it('should test string by value rather than by reference (DART)', () => {
        m.set('foo', 'bar');
        changes.check(m);

        var f = 'f';
        var oo = 'oo';
        var b = 'b';
        var ar = 'ar';

        m.set(f + oo, b + ar);
        changes.check(m);

        expect(changes.toString()).toEqual(kvChangesAsString({map: ['foo'], previous: ['foo']}));
      });

      it('should not see a NaN value as a change (JS)', () => {
        m.set('foo', NumberWrapper.NaN);
        changes.check(m);

        changes.check(m);
        expect(changes.toString()).toEqual(kvChangesAsString({map: ['foo'], previous: ['foo']}));
      });

      // JS specific tests (JS Objects)
      if (isJsObject({})) {
        describe('JsObject changes', () => {
          it('should support JS Object', () => {
            expect(KeyValueChanges.supportsObj({})).toBeTruthy();
            expect(KeyValueChanges.supportsObj("not supported")).toBeFalsy();
            expect(KeyValueChanges.supportsObj(0)).toBeFalsy();
            expect(KeyValueChanges.supportsObj(null)).toBeFalsy();
          });

          it('should do basic object watching', () => {
            let m = {};
            changes.check(m);

            m['a'] = 'A';
            changes.check(m);
            expect(changes.toString())
                .toEqual(kvChangesAsString({map: ['a[null->A]'], additions: ['a[null->A]']}));

            m['b'] = 'B';
            changes.check(m);
            expect(changes.toString())
                .toEqual(kvChangesAsString(
                    {map: ['a', 'b[null->B]'], previous: ['a'], additions: ['b[null->B]']}));

            m['b'] = 'BB';
            m['d'] = 'D';
            changes.check(m);
            expect(changes.toString())
                .toEqual(kvChangesAsString({
                  map: ['a', 'b[B->BB]', 'd[null->D]'],
                  previous: ['a', 'b[B->BB]'],
                  additions: ['d[null->D]'],
                  changes: ['b[B->BB]']
                }));

            m = {};
            m['a'] = 'A';
            m['d'] = 'D';
            changes.check(m);
            expect(changes.toString())
                .toEqual(kvChangesAsString({
                  map: ['a', 'd'],
                  previous: ['a', 'b[BB->null]', 'd'],
                  removals: ['b[BB->null]']
                }));

            m = {};
            changes.check(m);
            expect(changes.toString())
                .toEqual(kvChangesAsString({
                  previous: ['a[A->null]', 'd[D->null]'],
                  removals: ['a[A->null]', 'd[D->null]']
                }));
          });
        });
      }
    });
  });
}