From efce13b1e10c47a0a32d799b02a5f15646cf6882 Mon Sep 17 00:00:00 2001
From: Brian Boyko <brian.boyko@gmail.com>
Date: Thu, 27 Sep 2018 00:55:30 +0200
Subject: [PATCH] shank() - array - duplicates Array.prototype.splice() except
 returns a new array instead of mutating in-place

Update shank.md

Update shank.md

Update shank.js

Update shank.test.js

Update tag_database

remove testlog
---
 snippet_data/snippets.json | 11 +++++++++++
 snippets/shank.md          | 23 +++++++++++++++++++++++
 tag_database               |  1 +
 test/shank/shank.js        |  5 +++++
 test/shank/shank.test.js   | 22 ++++++++++++++++++++++
 5 files changed, 62 insertions(+)
 create mode 100644 snippets/shank.md
 create mode 100644 test/shank/shank.js
 create mode 100644 test/shank/shank.test.js

diff --git a/snippet_data/snippets.json b/snippet_data/snippets.json
index 7d55849e0..4a3cbaf9d 100644
--- a/snippet_data/snippets.json
+++ b/snippet_data/snippets.json
@@ -5186,6 +5186,17 @@
         "hash": "a5a49641c0de1a0a80f192c5be195c448ab0fe0856bba4e1f246fe70af7b5431"
       }
     },
+    {
+      "id": "shank",
+      "type": "snippet",
+      "attributes": {
+        "fileName": "shank.md",
+        "text": "Duplicates Array.prototype.splice, except it returns a new array rather than mutating the original array in place.",
+        "tags": [
+          "array"
+        ]
+      },
+    },
     {
       "id": "show",
       "type": "snippet",
diff --git a/snippets/shank.md b/snippets/shank.md
new file mode 100644
index 000000000..daa944d19
--- /dev/null
+++ b/snippets/shank.md
@@ -0,0 +1,23 @@
+### shank
+
+Has the same functionality as [`Array.prototype.splice()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/splice), but returning a new array instead of mutating the original array.
+
+Use `Array.slice()` and `Array.concat()` to get a new array with the new contents after removing existing elements and/or adding new elements.
+Omit the second argument, `index`, to start at `0`.
+Omit the third argument, `delCount`, to remove `0` elements.
+Omit the fourth argument, `elements`, in order to not add any new elements.
+
+```js
+const shank = (arr, index = 0, delCount = 0, ...elements) => 
+  arr.slice(0, index)
+     .concat(elements)
+     .concat(arr.slice(index + delCount));
+```
+
+```js
+const names = ['alpha', 'bravo', 'charlie'];
+const namesAndDelta = shank(names, 1, 0, 'delta'); // [ 'alpha', 'delta', 'bravo', 'charlie' ]
+const namesNoBravo = shank(names, 1, 1); // [ 'alpha', 'charlie' ]
+console.log(names); // ['alpha', 'bravo', 'charlie']
+```
+
diff --git a/tag_database b/tag_database
index f9148976d..effd2036f 100644
--- a/tag_database
+++ b/tag_database
@@ -247,6 +247,7 @@ sdbm:math,utility,intermediate
 serializeCookie:utility,string,intermediate
 setStyle:browser,beginner
 shallowClone:object,beginner
+shank:array,intermediate
 show:browser,css,beginner
 shuffle:array,random,intermediate
 similarity:array,math,beginner
diff --git a/test/shank/shank.js b/test/shank/shank.js
new file mode 100644
index 000000000..bf9076a48
--- /dev/null
+++ b/test/shank/shank.js
@@ -0,0 +1,5 @@
+const shank = (arr, index = 0, delCount = 0, ...elements) => 
+  arr.slice(0, index)
+     .concat(elements)
+     .concat(arr.slice(index + delCount));
+module.exports = shank;
diff --git a/test/shank/shank.test.js b/test/shank/shank.test.js
new file mode 100644
index 000000000..e14414748
--- /dev/null
+++ b/test/shank/shank.test.js
@@ -0,0 +1,22 @@
+const expect = require("expect");
+const shank = require("./shank.js");
+
+test("shank is a Function", () => {
+  expect(shank).toBeInstanceOf(Function);
+});
+
+const names = ['alpha', 'bravo', 'charlie'];
+
+test("Returns an array with the added elements.", () => {
+  expect(shank(names, 1, 0, 'delta')).toEqual(['alpha', 'delta', 'bravo', 'charlie']);
+});
+
+test("Returns an array with the removed elements.", () => {
+  expect(shank(names, 1, 1)).toEqual(['alpha', 'charlie']);
+});
+
+test("Does not mutate the original array", () => {
+  shank(names, 1, 0, 'delta');
+  expect(names).toEqual(['alpha', 'bravo', 'charlie']);
+});
+