@danielkalen/simplybind/test/specs/data-binding/type-Function.coffee

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

suite "Function", ()->
	test "Will be invoked on bind and have its return value used as the value that the subscribers will receive", ()->
		SimplyBind ()-> 123
			.to('prop').of(objectA)

		expect(objectA.prop).to.equal 123
	

	test "Will be invoked on bind as a dependent and will receive 2 arguments - 1st is the new value passed while the 2nd is the prev value passed", ()->
		invokeCount = 0
		objectA.prop1 = 'some value'
		SimplyBind('prop1').of(objectA)
			.to (newValue, prevValue)->
				switch invokeCount
					when 0
						expect(newValue).to.equal 'some value'
						expect(prevValue).to.be.undefined
					when 1
						expect(newValue).to.equal 'new value'
						expect(prevValue).to.equal 'some value'
					when 2
						expect(newValue).to.equal 'newer value'
						expect(prevValue).to.equal 'new value'
				invokeCount++

		objectA.prop1 = 'new value'
		objectA.prop1 = 'newer value'

		restartSandbox()


	test "Will be invoked when is the first part of an argument regardless of whether or not SimplyBind.options.updateOnBind is on", ()->
		invokeCount = 0
		expect(SimplyBind.defaultOptions.updateOnBind).to.be.true
		
		SimplyBind ()-> invokeCount++; 123
			.to('prop').of(objectA)
		expect(invokeCount).to.equal 1

		
		SimplyBind.defaultOptions.updateOnBind = false

		SimplyBind ()-> invokeCount++; 456
			.to('prop').of(objectA)
		expect(invokeCount).to.equal 2

		SimplyBind.defaultOptions.updateOnBind = true