pulsar/spec/view-registry-spec.js
2017-10-21 10:10:06 -04:00

217 lines
6.6 KiB
JavaScript

/*
* decaffeinate suggestions:
* DS102: Remove unnecessary code created because of implicit returns
* DS207: Consider shorter variations of null checks
* Full docs: https://github.com/decaffeinate/decaffeinate/blob/master/docs/suggestions.md
*/
const ViewRegistry = require('../src/view-registry')
describe('ViewRegistry', () => {
let registry = null
beforeEach(() => {
registry = new ViewRegistry()
})
afterEach(() => {
registry.clearDocumentRequests()
})
describe('::getView(object)', () => {
describe('when passed a DOM node', () =>
it('returns the given DOM node', () => {
const node = document.createElement('div')
expect(registry.getView(node)).toBe(node)
})
)
describe('when passed an object with an element property', () =>
it("returns the element property if it's an instance of HTMLElement", () => {
class TestComponent {
constructor () {
this.element = document.createElement('div')
}
}
const component = new TestComponent()
expect(registry.getView(component)).toBe(component.element)
})
)
describe('when passed an object with a getElement function', () =>
it("returns the return value of getElement if it's an instance of HTMLElement", () => {
class TestComponent {
getElement () {
if (this.myElement == null) {
this.myElement = document.createElement('div')
}
return this.myElement
}
}
const component = new TestComponent()
expect(registry.getView(component)).toBe(component.myElement)
})
)
describe('when passed a model object', () => {
describe("when a view provider is registered matching the object's constructor", () =>
it('constructs a view element and assigns the model on it', () => {
class TestModel {}
class TestModelSubclass extends TestModel {}
class TestView {
initialize (model) {
this.model = model
return this
}
}
const model = new TestModel()
registry.addViewProvider(TestModel, (model) =>
new TestView().initialize(model)
)
const view = registry.getView(model)
expect(view instanceof TestView).toBe(true)
expect(view.model).toBe(model)
const subclassModel = new TestModelSubclass()
const view2 = registry.getView(subclassModel)
expect(view2 instanceof TestView).toBe(true)
expect(view2.model).toBe(subclassModel)
})
)
describe('when a view provider is registered generically, and works with the object', () =>
it('constructs a view element and assigns the model on it', () => {
registry.addViewProvider((model) => {
if (model.a === 'b') {
const element = document.createElement('div')
element.className = 'test-element'
return element
}
})
const view = registry.getView({a: 'b'})
expect(view.className).toBe('test-element')
expect(() => registry.getView({a: 'c'})).toThrow()
})
)
describe("when no view provider is registered for the object's constructor", () =>
it('throws an exception', () => {
expect(() => registry.getView({})).toThrow()
})
)
})
})
describe('::addViewProvider(providerSpec)', () =>
it('returns a disposable that can be used to remove the provider', () => {
class TestModel {}
class TestView {
initialize (model) {
this.model = model
return this
}
}
const disposable = registry.addViewProvider(TestModel, (model) =>
new TestView().initialize(model)
)
expect(registry.getView(new TestModel()) instanceof TestView).toBe(true)
disposable.dispose()
expect(() => registry.getView(new TestModel())).toThrow()
})
)
describe('::updateDocument(fn) and ::readDocument(fn)', () => {
let frameRequests = null
beforeEach(() => {
frameRequests = []
spyOn(window, 'requestAnimationFrame').andCallFake(fn => frameRequests.push(fn))
})
it('performs all pending writes before all pending reads on the next animation frame', () => {
let events = []
registry.updateDocument(() => events.push('write 1'))
registry.readDocument(() => events.push('read 1'))
registry.readDocument(() => events.push('read 2'))
registry.updateDocument(() => events.push('write 2'))
expect(events).toEqual([])
expect(frameRequests.length).toBe(1)
frameRequests[0]()
expect(events).toEqual(['write 1', 'write 2', 'read 1', 'read 2'])
frameRequests = []
events = []
const disposable = registry.updateDocument(() => events.push('write 3'))
registry.updateDocument(() => events.push('write 4'))
registry.readDocument(() => events.push('read 3'))
disposable.dispose()
expect(frameRequests.length).toBe(1)
frameRequests[0]()
expect(events).toEqual(['write 4', 'read 3'])
})
it('performs writes requested from read callbacks in the same animation frame', () => {
spyOn(window, 'setInterval').andCallFake(fakeSetInterval)
spyOn(window, 'clearInterval').andCallFake(fakeClearInterval)
const events = []
registry.updateDocument(() => events.push('write 1'))
registry.readDocument(() => {
registry.updateDocument(() => events.push('write from read 1'))
events.push('read 1')
})
registry.readDocument(() => {
registry.updateDocument(() => events.push('write from read 2'))
events.push('read 2')
})
registry.updateDocument(() => events.push('write 2'))
expect(frameRequests.length).toBe(1)
frameRequests[0]()
expect(frameRequests.length).toBe(1)
expect(events).toEqual([
'write 1',
'write 2',
'read 1',
'read 2',
'write from read 1',
'write from read 2'
])
})
})
describe('::getNextUpdatePromise()', () =>
it('returns a promise that resolves at the end of the next update cycle', () => {
let updateCalled = false
let readCalled = false
waitsFor('getNextUpdatePromise to resolve', (done) => {
registry.getNextUpdatePromise().then(() => {
expect(updateCalled).toBe(true)
expect(readCalled).toBe(true)
done()
})
registry.updateDocument(() => { updateCalled = true })
registry.readDocument(() => { readCalled = true })
})
})
)
})