update docs and naming

Author: grindcode

README.md

@@ -9,13 +9,13 @@ npm install flat-insert
 ```
 
 ## API
-### insert(input, value, [index])
-Returns new `string` or `array` depending on `input` type.
-* `input`: Input value to be modified. (**String**|**Array**)
-* `value`: Any value to be inserted into `input`. (**mixed**)
+### insert(input, value[, index])
+Returns new modified value depending on `input` type.
+* `input`: Input value. (**String**|**Array**)
+* `value`: Value to be inserted. (**Mixed**)
   *  If `input` type is _String_, `value` will be turned into _String_.
   *  If `input` and `value` types are _Array_, then `value` will be flatten.
-* `index`: Index or position at `input` where insert `value`. (**Number**; default: `0`)
+* `index`: Index position for insertion. (**Number**; defaults `0`)
 
 ### Usage
 ```javascript

index.js

@@ -1,7 +1,15 @@
-module.exports = function (res, val, i) {
-  if (typeof res !== 'string' && !Array.isArray(res))
+var slice = require('lodash.slice')
+/**
+ * Returns a new Array or String after inserting and flatten value at index.
+ * @param {Array|String} input - Input value.
+ * @param {Mixed} value - Array, String or Number to be inserted.
+ * @param {Number} index - Index position for insertion.
+ * @returns {Array|String} New modified value depending on `input` type.
+ */
+module.exports = function (input, value, index) {
+  if (typeof input !== 'string' && !Array.isArray(input))
     throw new TypeError('First argument invalid. Expected Array or String.')
-  if (typeof i !== 'undefined' && typeof i !== 'number')
+  if (typeof index !== 'undefined' && typeof index !== 'number')
     throw new TypeError('Third argument invalid. Expected Number.')
-  return res.slice(0, i || 0).concat(val).concat(res.slice(i || 0))
+  return input.slice(0, index || 0).concat(value).concat(input.slice(index || 0))
 }

package.json

@@ -37,5 +37,9 @@
   "devDependencies": {
     "benchmark": "^2.1.0",
     "tape": "^4.4.0"
+  },
+  "dependencies": {
+    "lodash.concat": "^4.0.1",
+    "lodash.slice": "^4.0.1"
   }
 }