feature(return off function when calling Spruce.on)

src/bus.js

@@ -9,6 +9,8 @@ export default {
         }
 
         this.events[name].push(callback)
+
+        return () => this.off(name, callback)
     },
 
     off(name, callback) {

src/index.js

@@ -69,7 +69,7 @@ const Spruce = {
     },
 
     on(name, callback) {
-        this.events.on(name, callback)
+        return this.events.on(name, callback)
     },
 
     off(name, callback) {

tests/bus.spec.js

@@ -89,7 +89,7 @@ test('.watch() > can listen for changes to property', async () => {
     expect(oldFixture).toEqual('stuff')
 })
 
-test('.off() > can unregister listener', async () => {
+test('.off() > can unregister listener', () => {
     let fixture = undefined;
 
     const callback = () => {
@@ -102,5 +102,19 @@ test('.off() > can unregister listener', async () => {
 
     Spruce.emit('fixture-event')
 
+    expect(fixture).toBeUndefined()
+})
+
+test('.off() > returned when calling .on()', () => {
+    let fixture = undefined;
+
+    let off = Spruce.on('fixture-event', () => {
+        fixture = 0
+    })
+
+    off()
+
+    Spruce.emit('fixture-event')
+
     expect(fixture).toBeUndefined()
 })