feat(mixin): support lodash chain

lib/aigle.js

@@ -3765,6 +3765,17 @@ function mixin(sources, opts = {}) {
     if (typeof func !== 'function' || Aigle[key] && !override) {
       return;
     }
+    // check lodash chain
+    if (key === 'chain') {
+      const obj = func();
+      if (obj && obj.__chain__) {
+        Aigle.chain = _resolve;
+        Aigle.prototype.value = function() {
+          return this;
+        };
+        return;
+      }
+    }
     const Proxy = createProxy(func, promisify);
     Aigle[key] = function(value, arg1, arg2, arg3) {
       return new Proxy(value, arg1, arg2, arg3)._execute();
@@ -3773,4 +3784,5 @@ function mixin(sources, opts = {}) {
       return addProxy(this, Proxy, arg1, arg2, arg3);
     };
   });
+  return Aigle;
 }

test/.eslintrc

@@ -1,3 +1,5 @@
+parserOptions:
+  ecmaVersion: 8
 rules:
   # Best Practices
   no-return-assign: "off"

test/lib/test.mixin.js

@@ -13,7 +13,8 @@ parallel('mixin', () => {
   it('should execute with function', () => {
 
     const test1 = value => value * 2;
-    Aigle.mixin({ test1 }, { promisify: false });
+    const obj = Aigle.mixin({ test1 }, { promisify: false });
+    assert.strictEqual(obj, Aigle);
     return Aigle.resolve(1)
       .test1()
       .then(value => assert.strictEqual(value, 2));
@@ -40,6 +41,16 @@ parallel('mixin', () => {
     return promise;
   });
 
+  it('should allow the lodash chain', async () => {
+
+    const lo = Aigle.mixin(_);
+    const array = await lo.chain([1, 2, 3])
+      .map(async n => Aigle.delay(DELAY, n * 2))
+      .value();
+    assert.deepEqual(array, [2, 4, 6]);
+    assert.strictEqual(await lo.sum(array), 12);
+  });
+
   it('should override Aigle functions', () => {
 
     Aigle.mixin({ map: _.map }, { override: true, promisify: false });