Complete spinal tap case

Author: ahcode0919

src/fcc-intermediate-algorithms/fcc-intermediate-algorithms.md

@@ -8,6 +8,7 @@ From the Freecodecamp Javascript Certification Intermediate Algorithms module
 - [Diff Two Arrays](#diff-two-arrays)
 - [Seek and Destroy](#seek-and-destroy)
 - [Wherefore Art Thou](#wherefore-art-thou)
+- [Spinal Tap Case](#spinal-tap-case)
 
 #### Sum All Numbers In a Range
 
@@ -69,3 +70,13 @@ export function whatIsInAName(collection, source) {
     });
 }
 ```
+
+#### Spinal Tap Case
+
+Convert a string to spinal case. Spinal case is all-lowercase-words-joined-by-dashes.
+
+```javascript
+export function spinalCase(str) {
+    return str.split(/[_\W]|(?=[A-Z])/).join('-').toLowerCase();
+}
+```

src/fcc-intermediate-algorithms/spinal_tap_case.js

@@ -0,0 +1,3 @@
+export function spinalCase(str) {
+    return str.split(/[_\W]|(?=[A-Z])/).join('-').toLowerCase();
+}

tests/fcc-intermediate-algorithms/spinal_tap_case.test.js

@@ -0,0 +1,7 @@
+import { spinalCase } from "../../src/fcc-intermediate-algorithms/spinal_tap_case";
+
+test('should join all words as lower case seperated by dashes', () => {
+    let str = "this_Is SpinalTap"
+    expect(spinalCase(str)).toBe("this-is-spinal-tap");
+    expect(str).toBe("this_Is SpinalTap");
+});