feat(finally): add finally method to AsyncAF & AsyncAfWrapper

lib/classes/AsyncAfWrapper.js

@@ -10,6 +10,9 @@ class AsyncAfWrapperProto {
   catch(reject) {
     return this.then(null, reject);
   }
+  finally(onFinally) {
+    return this.data.finally(onFinally);
+  }
 }
 
 class AsyncAfWrapper extends AsyncAfWrapperProto {}

test/methods/other/finally.test.js

@@ -0,0 +1,21 @@
+import {expect} from 'chai';
+
+import AsyncAF from '../../../dist/async-af';
+
+describe('finally method', () => {
+  it('should not receive any argument', async () => {
+    let undefinedVar;
+    await AsyncAF(6).then(n => n * 2).finally(n => { undefinedVar = n; });
+    expect(undefinedVar).to.be.undefined;
+  });
+  it('should call onFinally after resolving', async () => {
+    const arr = [];
+    await AsyncAF(1).then(n => arr.push(n)).finally(() => arr.push(2));
+    expect(arr).to.eql([1, 2]);
+  });
+  it('should call onFinally after rejecting', async () => {
+    const arr = [];
+    await AsyncAF(6).then(() => { throw Error(); }).catch(e => e).finally(() => arr.push(1));
+    expect(arr).to.eql([1]);
+  });
+});