Add helpers and remove lodash dependency

configure/request-next.js

@@ -1,9 +1,10 @@
 'use strict';
 
 var core = require('../'),
+    helpers = require('../lib/helpers'),
     isArray = Array.isArray,
-    isFunction = require('lodash.isfunction'),
-    isObjectLike = require('lodash.isobjectlike');
+    isFunction = helpers.isFunction,
+    isObjectLike = helpers.isObjectLike;
 
 
 module.exports = function (options) {

configure/request2.js

@@ -1,9 +1,10 @@
 'use strict';
 
 var core = require('../'),
+    helpers = require('../lib/helpers'),
     isArray = Array.isArray,
-    isFunction = require('lodash.isfunction'),
-    isObjectLike = require('lodash.isobjectlike');
+    isFunction = helpers.isFunction,
+    isObjectLike = helpers.isObjectLike;
 
 
 module.exports = function (options) {

lib/helpers.js

@@ -0,0 +1,51 @@
+'use strict';
+
+var
+    asyncTag = '[object AsyncFunction]',
+    funcTag = '[object Function]',
+    genTag = '[object GeneratorFunction]',
+    proxyTag = '[object Proxy]',
+    nullTag = '[object Null]',
+    stringTag = '[object String]',
+    undefinedTag = '[object Undefined]';
+
+function baseGetTag(value) {
+    if (value === undefined) {
+        return undefinedTag;
+    }
+
+    if (value === null) {
+        return nullTag;
+    }
+
+    return Object.prototype.toString.call(value);
+}
+
+function isObject(value) {
+    var type = typeof value;
+    return value !== undefined && value !== null && (type === 'object' || type === 'function');
+}
+
+function isFunction(value) {
+    if (!isObject(value)) {
+        return false;
+    }
+
+    var tag = baseGetTag(value);
+    return tag === funcTag || tag === genTag || tag === asyncTag || tag === proxyTag;
+}
+
+function isObjectLike(value) {
+    return value !== undefined && value !== null && typeof value === 'object';
+}
+
+function isString(value) {
+    return typeof value === 'string' ||
+    !Array.isArray(value) && isObjectLike(value) && baseGetTag(value) === stringTag;
+}
+
+module.exports = {
+    isFunction: isFunction,
+    isString: isString,
+    isObjectLike: isObjectLike
+};

lib/plumbing.js

@@ -1,10 +1,10 @@
 'use strict';
 
 var errors = require('./errors.js'),
-    isFunction = require('lodash.isfunction'),
-    isObjectLike = require('lodash.isobjectlike'),
-    isString = require('lodash.isstring'),
-    isUndefined = require('lodash.isundefined');
+    helpers = require('./helpers'),
+    isFunction = helpers.isFunction,
+    isObjectLike = helpers.isObjectLike,
+    isString = helpers.isString;
 
 
 module.exports = function (options) {
@@ -19,7 +19,7 @@ module.exports = function (options) {
         throw new TypeError(errorText + '.PromiseImpl');
     }
 
-    if (!isUndefined(options.constructorMixin) && !isFunction(options.constructorMixin)) {
+    if (options.constructorMixin !== undefined && !isFunction(options.constructorMixin)) {
         throw new TypeError(errorText + '.PromiseImpl');
     }
 

package.json

@@ -32,12 +32,6 @@
   "engines": {
     "node": ">=0.10.0"
   },
-  "dependencies": {
-    "lodash.isfunction": "^3.0.9",
-    "lodash.isobjectlike": "^4.0.0",
-    "lodash.isstring": "^4.0.1",
-    "lodash.isundefined": "^3.0.1"
-  },
   "peerDependencies": {
     "request": "^2.34"
   },
@@ -54,6 +48,7 @@
     "gulp-istanbul": "~1.0.0",
     "gulp-mocha": "~2.2.0",
     "lodash.flatten": "^4.4.0",
+    "lodash.isfunction": "^3.0.9",
     "node-version": "~1.0.0",
     "publish-please": "~2.4.1",
     "request": "^2.34.0",