Add batch test

packages/imba/test/apps/observables/batch.imba

@@ -0,0 +1,31 @@
+import 'imba/spec'
+
+let calls = 0
+let runs = 0
+
+class Base
+	@observable array = []
+
+	@computed get size
+		calls++
+		array.slice(0).length
+
+	@autorun def stuff
+		runs++
+		array.slice(0).length
+
+
+test do
+	let base = new Base
+	base.size
+	imba.atomic do
+		for i in [0 ... 100]
+			base.array.push(10)
+	base.size
+	base.size
+
+	eq base.size, 100
+	ok calls == 2
+	eq runs, 2
+
+SPEC.run!