Add mapString, fix dig

snippets/dig.md

@@ -5,7 +5,7 @@ Returns the target value in a nested JSON object, based on the given key.
 Use the `in` operator to check if `target` exists in `obj`.
 If found, return the value of `obj[target]`, otherwise use `Object.values(obj)` and `Array.reduce()` to recursively call `dig` on each nested object until the first matching key/value pair is found.
 
-```
+```js
 const dig = (obj, target) =>
   target in obj
     ? obj[target]
@@ -17,7 +17,7 @@ const dig = (obj, target) =>
         }, undefined);
 ```
 
-```
+```js
 const data = {
   level1:{
     level2:{

snippets/mapString.md

@@ -0,0 +1,16 @@
+### mapString
+
+Creates a new string with the results of calling a provided function on every character in the calling string.
+
+Use `String.split('')` and `Array.map()` to call the provided function, `fn`, for each character in `str`.
+Use `Array.join('')` to recombine the array of characters into a string.
+The callback function, `fn`, takes three arguments (the current character, the index of the current character and the string `mapString` was called upon).
+
+```js
+const mapString = (str, fn) =>
+	str.split('').map((c, i) => fn(c, i, str)).join('');
+```
+
+```js
+mapString('lorem ipsum', c => c.toUpperCase()); // 'LOREM IPSUM'
+```

tag_database

@@ -162,6 +162,7 @@ lowercaseKeys:object
 luhnCheck:math,utility
 mapKeys:object,function
 mapObject:array,object,advanced
+mapString:string,array,function,utility
 mapValues:object,function
 mask:string,utility,regexp
 matches:object,type

test/dig/dig.js

@@ -4,12 +4,7 @@ const dig = (obj, target) =>
 : Object
 .values(obj)
 .reduce((acc, val) => {
-          if (acc !== undefined) {
-            return acc;
-          }
-          if (typeof val === "object") {
-            return dig(val, target);
-          }
+if (acc !== undefined) return acc;
+if (typeof val === 'object') return dig(val, target);
 }, undefined);
-
 module.exports = dig;

test/mapString/mapString.js

@@ -0,0 +1,3 @@
+const mapString = (str, fn) =>
+str.split('').map((c, i) => fn(c, i, str)).join('');
+module.exports = mapString;

test/mapString/mapString.test.js

@@ -0,0 +1,20 @@
+const expect = require('expect');
+const mapString = require('./mapString.js');
+
+test('mapString is a Function', () => {
+  expect(mapString).toBeInstanceOf(Function);
+});
+
+test('mapString returns a capitalized string', () => {
+  expect(mapString('test', c => c.toUpperCase())).toBe('TEST');
+});
+
+const indexMapper = (c, i) => `${c}[${i}]`;
+test('mapString can deal with indexes', () => {
+  expect(mapString('test', indexMapper)).toBe('t[0]e[1]s[2]t[3]');
+});
+
+const fullStringMapper = (c, i, str) => `{${str}}${c}[${i}]`;
+test('mapString can deal with the full string', () => {
+  expect(mapString('test', fullStringMapper)).toBe('{test}t[0]{test}e[1]{test}s[2]{test}t[3]');
+});