angular-docs-cn/modules/change_detection/test/change_detection_spec.js

import {ddescribe, describe, it, iit, xit, expect, beforeEach, afterEach} from 'test_lib/test_lib';

import {isPresent, isBlank, isJsObject, BaseException, FunctionWrapper} from 'facade/lang';
import {List, ListWrapper, MapWrapper, StringMapWrapper} from 'facade/collection';

import {Parser} from 'change_detection/parser/parser';
import {Lexer} from 'change_detection/parser/lexer';
import {reflector} from 'reflection/reflection';
import {arrayChangesAsString, kvChangesAsString} from './util';

import {ProtoChangeDetector, ChangeDispatcher, DynamicChangeDetector, ChangeDetectionError,
  ContextWithVariableBindings}
  from 'change_detection/change_detection';


export function main() {
  function ast(exp:string, location:string = 'location') {
    var parser = new Parser(new Lexer());
    return parser.parseBinding(exp, location);
  }

  function createChangeDetector(memo:string, exp:string, context = null, formatters = null,
                                structural = false) {
    var pcd = new ProtoChangeDetector();
    pcd.addAst(ast(exp), memo, memo, structural);

    var dispatcher = new TestDispatcher();
    var cd = pcd.instantiate(dispatcher, formatters);
    cd.setContext(context);

    return {"changeDetector" : cd, "dispatcher" : dispatcher};
  }

  function executeWatch(memo:string, exp:string, context = null, formatters = null,
                        content = false) {
    var res = createChangeDetector(memo, exp, context, formatters, content);
    res["changeDetector"].detectChanges();
    return res["dispatcher"].log;
  }

  describe('change_detection', () => {
    it('should do simple watching', () => {
      var person = new Person("misko");
      var c = createChangeDetector('name', 'name', person);
      var cd = c["changeDetector"];
      var dispatcher = c["dispatcher"];

      cd.detectChanges();
      expect(dispatcher.log).toEqual(['name=misko']);

      dispatcher.clear();
      cd.detectChanges();
      expect(dispatcher.log).toEqual([]);

      person.name = "Misko";
      cd.detectChanges();
      expect(dispatcher.log).toEqual(['name=Misko']);
    });

    it('should report all changes on the first run including uninitialized values', () => {
      var uninit = new Uninitialized();
      var c = createChangeDetector('value', 'value', uninit);
      var cd = c["changeDetector"];
      var dispatcher = c["dispatcher"];

      cd.detectChanges();
      expect(dispatcher.log).toEqual(['value=null']);
    });

    it("should support literals", () => {
      expect(executeWatch('const', '10')).toEqual(['const=10']);
      expect(executeWatch('const', '"str"')).toEqual(['const=str']);
    });

    it('simple chained property access', () => {
      var address = new Address('Grenoble');
      var person = new Person('Victor', address);

      expect(executeWatch('address.city', 'address.city', person))
        .toEqual(['address.city=Grenoble']);
    });

    it("should support method calls", () => {
      var person = new Person('Victor');
      expect(executeWatch('m', 'sayHi("Jim")', person)).toEqual(['m=Hi, Jim']);
    });

    it("should support function calls", () => {
      var td = new TestData(() => (a) => a);
      expect(executeWatch('value', 'a()(99)', td)).toEqual(['value=99']);
    });

    it("should support chained method calls", () => {
      var person = new Person('Victor');
      var td = new TestData(person);
      expect(executeWatch('m', 'a.sayHi("Jim")', td)).toEqual(['m=Hi, Jim']);
    });

    it("should support literal array", () => {
      var c = createChangeDetector('array', '[1,2]');
      c["changeDetector"].detectChanges();
      expect(c["dispatcher"].loggedValues).toEqual([[[1,2]]]);

      c = createChangeDetector('array', '[1,a]', new TestData(2));
      c["changeDetector"].detectChanges();
      expect(c["dispatcher"].loggedValues).toEqual([[[1,2]]]);
    });

    it("should support literal maps", () => {
      var c = createChangeDetector('map', '{z:1}');
      c["changeDetector"].detectChanges();
      expect(c["dispatcher"].loggedValues[0][0]['z']).toEqual(1);

      c = createChangeDetector('map', '{z:a}', new TestData(1));
      c["changeDetector"].detectChanges();
      expect(c["dispatcher"].loggedValues[0][0]['z']).toEqual(1);
    });

    it("should support binary operations", () => {
      expect(executeWatch('exp', '10 + 2')).toEqual(['exp=12']);
      expect(executeWatch('exp', '10 - 2')).toEqual(['exp=8']);

      expect(executeWatch('exp', '10 * 2')).toEqual(['exp=20']);
      expect(executeWatch('exp', '10 / 2')).toEqual([`exp=${5.0}`]); //dart exp=5.0, js exp=5
      expect(executeWatch('exp', '11 % 2')).toEqual(['exp=1']);

      expect(executeWatch('exp', '1 == 1')).toEqual(['exp=true']);
      expect(executeWatch('exp', '1 != 1')).toEqual(['exp=false']);

      expect(executeWatch('exp', '1 < 2')).toEqual(['exp=true']);
      expect(executeWatch('exp', '2 < 1')).toEqual(['exp=false']);

      expect(executeWatch('exp', '2 > 1')).toEqual(['exp=true']);
      expect(executeWatch('exp', '2 < 1')).toEqual(['exp=false']);

      expect(executeWatch('exp', '1 <= 2')).toEqual(['exp=true']);
      expect(executeWatch('exp', '2 <= 2')).toEqual(['exp=true']);
      expect(executeWatch('exp', '2 <= 1')).toEqual(['exp=false']);

      expect(executeWatch('exp', '2 >= 1')).toEqual(['exp=true']);
      expect(executeWatch('exp', '2 >= 2')).toEqual(['exp=true']);
      expect(executeWatch('exp', '1 >= 2')).toEqual(['exp=false']);

      expect(executeWatch('exp', 'true && true')).toEqual(['exp=true']);
      expect(executeWatch('exp', 'true && false')).toEqual(['exp=false']);

      expect(executeWatch('exp', 'true || false')).toEqual(['exp=true']);
      expect(executeWatch('exp', 'false || false')).toEqual(['exp=false']);
    });

    it("should support negate", () => {
      expect(executeWatch('exp', '!true')).toEqual(['exp=false']);
      expect(executeWatch('exp', '!!true')).toEqual(['exp=true']);
    });

    it("should support conditionals", () => {
      expect(executeWatch('m', '1 < 2 ? 1 : 2')).toEqual(['m=1']);
      expect(executeWatch('m', '1 > 2 ? 1 : 2')).toEqual(['m=2']);
    });

    describe("keyed access", () => {
      it("should support accessing a list item", () => {
        expect(executeWatch('array[0]', '["foo", "bar"][0]')).toEqual(['array[0]=foo']);
      });

      it("should support accessing a map item", () => {
        expect(executeWatch('map[foo]', '{"foo": "bar"}["foo"]')).toEqual(['map[foo]=bar']);
      });
    });

    it("should support formatters", () => {
      var formatters = MapWrapper.createFromPairs([
        ['uppercase', (v) => v.toUpperCase()],
        ['wrap', (v, before, after) => `${before}${v}${after}`]]);
      expect(executeWatch('str', '"aBc" | uppercase', null, formatters)).toEqual(['str=ABC']);
      expect(executeWatch('str', '"b" | wrap:"a":"c"', null, formatters)).toEqual(['str=abc']);
    });

    describe("group changes", () => {
      it("should notify the dispatcher when a group of records changes", () => {
        var pcd = new ProtoChangeDetector();
        pcd.addAst(ast("1 + 2"), "memo", 1);
        pcd.addAst(ast("10 + 20"), "memo", 1);
        pcd.addAst(ast("100 + 200"), "memo2", 2);

        var dispatcher = new TestDispatcher();
        var cd = pcd.instantiate(dispatcher, null);

        cd.detectChanges();

        expect(dispatcher.loggedValues).toEqual([[3, 30], [300]]);
      });

      it("should update every instance of a group individually", () => {
        var pcd = new ProtoChangeDetector();
        pcd.addAst(ast("1 + 2"), "memo", "memo");

        var dispatcher = new TestDispatcher();
        var cd = new DynamicChangeDetector(dispatcher, null, []);
        cd.addChild(pcd.instantiate(dispatcher, null));
        cd.addChild(pcd.instantiate(dispatcher, null));

        cd.detectChanges();

        expect(dispatcher.loggedValues).toEqual([[3], [3]]);
      });

      it("should notify the dispatcher before switching to the next group", () => {
        var pcd = new ProtoChangeDetector();
        pcd.addAst(ast("a()"), "a", 1);
        pcd.addAst(ast("b()"), "b", 2);
        pcd.addAst(ast("c()"), "c", 2);

        var dispatcher = new TestDispatcher();
        var cd = pcd.instantiate(dispatcher, null);

        var tr = new TestRecord();
        tr.a = () => {dispatcher.logValue('InvokeA'); return 'a'};
        tr.b = () => {dispatcher.logValue('InvokeB'); return 'b'};
        tr.c = () => {dispatcher.logValue('InvokeC'); return 'c'};
        cd.setContext(tr);

        cd.detectChanges();

        expect(dispatcher.loggedValues).toEqual(['InvokeA', ['a'], 'InvokeB', 'InvokeC', ['b', 'c']]);
      });
    });

    describe("enforce no new changes", () => {
      it("should throw when a record gets changed after it has been checked", () => {
        var pcd = new ProtoChangeDetector();
        pcd.addAst(ast("a"), "a", 1);

        var dispatcher = new TestDispatcher();
        var cd = pcd.instantiate(dispatcher, null);
        cd.setContext(new TestData('value'));

        expect(() => {
          cd.checkNoChanges();
        }).toThrowError(new RegExp("Expression 'a in location' has changed after it was checked"));
      });
    });

    describe("error handling", () => {
      it("should wrap exceptions into ChangeDetectionError", () => {
        var pcd = new ProtoChangeDetector();
        pcd.addAst(ast('invalidProp', 'someComponent'), "a", 1);

        var cd = pcd.instantiate(new TestDispatcher(), null);
        cd.setContext(null);

        try {
          cd.detectChanges();
          throw new BaseException("fail");
        } catch (e) {
          expect(e).toBeAnInstanceOf(ChangeDetectionError);
          expect(e.location).toEqual("invalidProp in someComponent");
        }
      });
    });

    describe("collections", () => {
      it("should support null values", () => {
        var context = new TestData(null);

        var c = createChangeDetector('a', 'a', context, null, true);
        var cd = c["changeDetector"];
        var dispatcher = c["dispatcher"];

        cd.detectChanges();
        expect(dispatcher.log).toEqual(['a=null']);
        dispatcher.clear();

        //cd.detectChanges();
        //expect(dispatcher.log).toEqual([]);

        context.a = [0];
        cd.detectChanges();

        expect(dispatcher.log).toEqual(["a=" +
          arrayChangesAsString({
            collection: ['0[null->0]'],
            additions: ['0[null->0]']
          })
        ]);
        dispatcher.clear();

        context.a = null;
        cd.detectChanges();
        expect(dispatcher.log).toEqual(['a=null']);
      });

      describe("list", () => {
        it("should support list changes", () => {
          var context = new TestData([1, 2]);

          expect(executeWatch("a", "a", context, null, true))
            .toEqual(["a=" +
            arrayChangesAsString({
              collection: ['1[null->0]', '2[null->1]'],
              additions: ['1[null->0]', '2[null->1]']
            })]);
        });

        it("should handle reference changes", () => {
          var context = new TestData([1, 2]);
          var objs = createChangeDetector("a", "a", context, null, true);
          var cd = objs["changeDetector"];
          var dispatcher = objs["dispatcher"];
          cd.detectChanges();
          dispatcher.clear();

          context.a = [2, 1];
          cd.detectChanges();
          expect(dispatcher.log).toEqual(["a=" +
          arrayChangesAsString({
            collection: ['2[1->0]', '1[0->1]'],
            previous: ['1[0->1]', '2[1->0]'],
            moves: ['2[1->0]', '1[0->1]']
          })]);
        });
      });

      describe("map", () => {
        it("should support map changes", () => {
          var map = MapWrapper.create();
          MapWrapper.set(map, "foo", "bar");
          var context = new TestData(map);
          expect(executeWatch("a", "a", context, null, true))
            .toEqual(["a=" +
            kvChangesAsString({
              map: ['foo[null->bar]'],
              additions: ['foo[null->bar]']
            })]);
        });

        it("should handle reference changes", () => {
          var map = MapWrapper.create();
          MapWrapper.set(map, "foo", "bar");
          var context = new TestData(map);
          var objs = createChangeDetector("a", "a", context, null, true);
          var cd = objs["changeDetector"];
          var dispatcher = objs["dispatcher"];
          cd.detectChanges();
          dispatcher.clear();

          context.a = MapWrapper.create();
          MapWrapper.set(context.a, "bar", "foo");
          cd.detectChanges();
          expect(dispatcher.log).toEqual(["a=" +
          kvChangesAsString({
            map: ['bar[null->foo]'],
            previous: ['foo[bar->null]'],
            additions: ['bar[null->foo]'],
            removals: ['foo[bar->null]']
          })]);
        });
      });

      if (isJsObject({})) {
        describe("js objects", () => {
          it("should support object changes", () => {
            var map = {"foo": "bar"};
            var context = new TestData(map);
            expect(executeWatch("a", "a", context, null, true))
              .toEqual(["a=" +
              kvChangesAsString({
                map: ['foo[null->bar]'],
                additions: ['foo[null->bar]']
              })]);
          });
        });
      }
    });

    describe("ContextWithVariableBindings", () => {
      it('should read a field from ContextWithVariableBindings', () => {
        var locals = new ContextWithVariableBindings(null,
          MapWrapper.createFromPairs([["key", "value"]]));

        expect(executeWatch('key', 'key', locals))
          .toEqual(['key=value']);
      });

      it('should handle nested ContextWithVariableBindings', () => {
        var nested = new ContextWithVariableBindings(null,
          MapWrapper.createFromPairs([["key", "value"]]));
        var locals = new ContextWithVariableBindings(nested, MapWrapper.create());

        expect(executeWatch('key', 'key', locals))
          .toEqual(['key=value']);
      });

      it("should fall back to a regular field read when ContextWithVariableBindings " +
        "does not have the requested field", () => {
        var locals = new ContextWithVariableBindings(new Person("Jim"),
          MapWrapper.createFromPairs([["key", "value"]]));

        expect(executeWatch('name', 'name', locals))
          .toEqual(['name=Jim']);
      });
    });
  });
}

class TestRecord {
  a;
  b;
  c;
}

class Person {
  name:string;
  age:number;
  address:Address;
  constructor(name:string, address:Address = null) {
    this.name = name;
    this.address = address;
  }

  sayHi(m) {
    return `Hi, ${m}`;
  }

  toString():string {
    var address = this.address == null ? '' : ' address=' + this.address.toString();

    return 'name=' + this.name + address;
  }
}

class Address {
  city:string;
  constructor(city:string) {
    this.city = city;
  }

  toString():string {
    return this.city;
  }
}

class Uninitialized {
  value:any;
}

class TestData {
  a;

  constructor(a) {
    this.a = a;
  }
}

class TestDispatcher extends ChangeDispatcher {
  log:List;
  loggedValues:List;
  onChange:Function;

  constructor() {
    this.log = null;
    this.loggedValues = null;
    this.onChange = (_, __) => {};
    this.clear();
  }

  clear() {
    this.log = ListWrapper.create();
    this.loggedValues = ListWrapper.create();
  }

  logValue(value) {
    ListWrapper.push(this.loggedValues, value);
  }

  onRecordChange(group, updates:List) {
    var value = updates[0].change.currentValue;
    var memento = updates[0].bindingMemento;
    ListWrapper.push(this.log, memento + '=' + this._asString(value));

    var values = ListWrapper.map(updates, (r) => r.change.currentValue);
    ListWrapper.push(this.loggedValues, values);

    this.onChange(group, updates);
  }


  _asString(value) {
    return (isBlank(value) ? 'null' : value.toString());
  }
}