allow observing $foo in dev mode - #1181

src/shared/index.js

@@ -100,7 +100,7 @@ export function observe(key, callback, options) {
 }
 
 export function observeDev(key, callback, options) {
-	var c = (key = '' + key).search(/[^\w]/);
+	var c = (key = '' + key).search(/[.[]/);
 	if (c > -1) {
 		var message =
 			'The first argument to component.observe(...) must be the name of a top-level property';

test/runtime/samples/store-observe-dollar/_config.js

@@ -0,0 +1,25 @@
+import { Store } from '../../../../store.js';
+
+const store = new Store({
+	name: 'world'
+});
+
+export default {
+	store,
+
+	html: `<h1>Hello world!</h1>`,
+
+	dev: true,
+
+	test(assert, component) {
+		const names = [];
+
+		component.observe('$name', name => {
+			names.push(name);
+		});
+
+		store.set({ name: 'everybody' });
+
+		assert.deepEqual(names, ['world', 'everybody']);
+	}
+};

test/runtime/samples/store-observe-dollar/main.html

@@ -0,0 +1 @@
+<h1>Hello {{$name}}!</h1>