@danielkalen/simplybind/test/specs/stage-2-methods/condition.coffee

Magically simple, framework-less one-way/two-way data binding for frontend/backend in ~5kb.

suite ".condition()", ()->
	suiteSetup(restartSandbox)

	test "Will pass the value to the condition before updating the dependent and will update the dep only if the return value is truthy", ()->
		shouldAllowUpdate = false
		objectA.prop1 = objectB.prop1 = 0

		SimplyBind('prop1').of(objectA)
			.to('prop1').of(objectB)
			.condition ()-> shouldAllowUpdate

		objectA.prop1 = 1
		expect(objectB.prop1).to.equal 0
		
		objectA.prop1 = 2
		expect(objectB.prop1).to.equal 0

		shouldAllowUpdate = true
		
		objectA.prop1 = 3
		expect(objectB.prop1).to.equal 3

		restartSandbox()



	test "Will update the dependent upon initial bind regardless of the condition unless SimplyBind.options.updateOnBind is on", ()->
		shouldAllowUpdate = false
		objectA.prop1 = objectA.prop2 = 1
		objectB.prop1 = objectB.prop2 = 0

		SimplyBind('prop1').of(objectA)
			.to('prop1').of(objectB)
			.condition ()-> shouldAllowUpdate

		expect(objectA.prop1).to.equal 1
		expect(objectB.prop1).to.equal 1

		objectA.prop1 = 2
		expect(objectB.prop1).to.equal 1

		
		
		SimplyBind.defaultOptions.updateOnBind = false
		
		SimplyBind('prop2').of(objectA)
			.to('prop2').of(objectB)
			.condition ()-> shouldAllowUpdate
		
		expect(objectA.prop2).to.equal 1
		expect(objectB.prop2).to.equal 0
		
		SimplyBind.defaultOptions.updateOnBind = true
		restartSandbox()




	test "Will receive the subject object as the third argument", ()->
		dispatcher = 'prop':1
		receivers = [objectA, objectB, objectC]
		index = 0

		SimplyBind('prop').of(dispatcher)
			.to('prop').of(objectA)
			.and.to('prop').of(objectB)
			.and.to('prop').of(objectC)
				.conditionAll (current, prev, target)->
					expect(target).to.equal(receivers[index++])
					return true

		dispatcher.prop++
		expect(index).to.equal(3)
		restartSandbox()



	test "Condition will be added only to the last-proxied dependent", ()->
		shouldAllowUpdate = false
		objectA.prop1 = objectB.prop1 = objectC.prop1 = 0

		SimplyBind('prop1').of(objectA)
			.to('prop1').of(objectB).condition ()-> shouldAllowUpdate
			.and.to('prop1').of(objectC)

		objectA.prop1 = 1
		expect(objectB.prop1).to.equal 0
		expect(objectC.prop1).to.equal 1
		
		objectA.prop1 = 2
		expect(objectB.prop1).to.equal 0
		expect(objectC.prop1).to.equal 2

		shouldAllowUpdate = true
		
		objectA.prop1 = 3
		expect(objectB.prop1).to.equal 3
		expect(objectC.prop1).to.equal 3

		restartSandbox()



	test "The condition will be added both ways if declared after the .bothWays() call", ()->
		shouldAllowUpdate = false
		objectA.prop1 = objectB.prop1 = 0

		SimplyBind('prop1').of(objectA)
			.to('prop1').of(objectB).bothWays()
				.condition ()-> shouldAllowUpdate

		objectA.prop1 = 1
		expect(objectA.prop1).to.equal 1
		expect(objectB.prop1).to.equal 0
		
		objectB.prop1 = 2
		expect(objectA.prop1).to.equal 1
		expect(objectB.prop1).to.equal 2

		shouldAllowUpdate = true
		
		objectA.prop1 = 3
		expect(objectA.prop1).to.equal 3
		expect(objectB.prop1).to.equal 3
		
		objectB.prop1 = 4
		expect(objectA.prop1).to.equal 4
		expect(objectB.prop1).to.equal 4

		restartSandbox()



	test "The condition will be added both ways if declared before the .bothWays() call", ()->
		shouldAllowUpdate = false
		objectA.prop1 = objectB.prop1 = 0

		SimplyBind('prop1').of(objectA)
			.to('prop1').of(objectB)
				.condition ()-> shouldAllowUpdate
				.bothWays()

		objectA.prop1 = 1
		expect(objectA.prop1).to.equal 1
		expect(objectB.prop1).to.equal 0
		
		objectB.prop1 = 2
		expect(objectA.prop1).to.equal 1
		expect(objectB.prop1).to.equal 2

		shouldAllowUpdate = true
		
		objectA.prop1 = 3
		expect(objectA.prop1).to.equal 3
		expect(objectB.prop1).to.equal 3
		
		objectB.prop1 = 4
		expect(objectA.prop1).to.equal 4
		expect(objectB.prop1).to.equal 4

		restartSandbox()



	test "If a the dependent has a transform and a condition, the new value will be run through the transform prior to testing the condition", ()->
		invokeCount = 0
		shouldAllowUpdate = true

		SimplyBind('prop1').of(objectA)
			.to('prop1').of(objectB)
				.transform (val)-> invokeCount++; val
				.condition ()-> shouldAllowUpdate

		expect(objectB.prop1).to.equal(objectA.prop1)
		expect(invokeCount).to.equal 1

		objectA.prop1 = 2
		expect(objectB.prop1).to.equal(objectA.prop1)
		expect(invokeCount).to.equal 2

		shouldAllowUpdate = false
		objectA.prop1 = 3
		expect(objectB.prop1).not.to.equal(objectA.prop1)
		expect(invokeCount).to.equal 3
		
		objectA.prop1 = 4
		expect(objectB.prop1).not.to.equal(objectA.prop1)
		expect(invokeCount).to.equal 4

		restartSandbox()



	test "If a binding has a placeholder, the condition will be used only for that placeholder", ()->
		dispatcher = 'prop':''
		receiver = 'prop':'This {{noun}} works'
		lastPassedNoun = null
		shouldAllowUpdate = true

		SimplyBind('prop').of(dispatcher)
			.to('prop.noun').of(receiver)
			.condition (noun)-> lastPassedNoun=noun; return shouldAllowUpdate

		dispatcher.prop = 'test1'
		expect(lastPassedNoun).to.equal 'test1'
		expect(receiver.prop).to.equal 'This test1 works'
		
		shouldAllowUpdate = false
		dispatcher.prop = 'test2'
		expect(lastPassedNoun).to.equal 'test2'
		expect(receiver.prop).to.equal 'This test1 works'