git ssb - computed: short circuit nextTick if value is read directly when live

Matt McKegg committed on 11/9/2017, 11:20:54 PM
Parent: fd48051c9a0ccc1e5fd254db048758d8eff91383

computed.js	changed
test/computed.js	changed

computed.jsView
		@@ -194,8 +194,11 @@
194	194 …	// temporarily become live to watch for changes until next cycle to stop
195	195 …	// potential double refresh and handle weird race conditions
196	196 …	this.listen() // triggers update
197	197 …	setImmediate(this.boundUnlisten) // only runs if no listeners have been added
	198 …	+ } else if (this.updating) {
	199 …	+ // short circuit nextTick if this value is read directly
	200 …	+ this.updateNow()
198	201 …	}
199	202 …	return this.outputValue
200	203 …	},
201	204 …	broadcast: function () {

test/computed.jsView
		@@ -56,4 +56,29 @@
56	56 …	t.deepEqual(obs(), 2)
57	57 …	t.end()
58	58 …	})
59	59 …	})
	60 …	+
WritePreview
	61 …	+test('computed nextTick, observe', function (t) {
	62 …	+ var events = []
	63 …	+ var value = Value(1)
	64 …	+ var obs = computed(value, x => x * 100, {nextTick: true})
	65 …	+ obs(value => events.push(value))
	66 …	+ value.set(2)
	67 …	+ t.deepEqual(events, [])
	68 …	+ value.set(3)
	69 …	+ t.deepEqual(events, [])
	70 …	+
	71 …	+ setImmediate(() => {
	72 …	+ t.deepEqual(events, [300])
	73 …	+ t.end()
	74 …	+ })
	75 …	+})
	76 …	+
	77 …	+test('computed nextTick, same tick `get` (short-circuit delay)', function (t) {
	78 …	+ var value = Value(1)
	79 …	+ var obs = computed(value, x => x * 100, {nextTick: true})
	80 …	+ t.equal(resolve(obs), 100)
	81 …	+ value.set(2)
	82 …	+ t.equal(resolve(obs), 200)
	83 …	+ t.end()
	84 …	+})

Matt McKegg / mutant