Replace Repeated Characters with JavaScript

By  on  

URLs can be tricky to work with because they can be more complicated than the traditional URL format you type in.  I was again reminded of this when I was parsing Webpack URLs when I saw this beauty:

webpack-internal:///../rbd/pnpm-volume/144384a5-85d9-4142-b9b9-168eea22eb97/node_modules/.registry.npmjs.org/fbjs/0.8.17/node_modules/fbjs/lib/isNode.js

I parsed the URL with new URL("....") but saw that the pathname included every leading slash:

///../rbd/pnpm-volume/144384a5-85d9-4142-b9b9-168eea22eb97/node_modules/.registry.npmjs.org/fbjs/0.8.17/node_modules/fbjs/lib/isNode.js


Since I wanted to display a sane pathname, I wanted to figure out how to remove/replace repeated characters with JavaScript.  It was actually easier than I thought it would be:

const prettyPath = urlObj.pathname.replace(/\/{2,}/g, "/");

// > /../rbd/pnpm-volume/144384a5-85d9-4142-b9b9-168eea22eb97/node_modules/.registry.npmjs.org/fbjs/0.8.17/node_modules/fbjs/lib/isNode.js

The {2,} part of the regular expression only allows for one of the repeated characters, and /g ensures that multiple instances within the string will have the repeat character removed.

Just when I thought I'd seen it all this Webpack URL surprised me.  Luckily a small regex let me show a pretty URL in page to the user!

Recent Features

  • By
    Regular Expressions for the Rest of Us

    Sooner or later you'll run across a regular expression. With their cryptic syntax, confusing documentation and massive learning curve, most developers settle for copying and pasting them from StackOverflow and hoping they work. But what if you could decode regular expressions and harness their power? In...

  • By
    9 Mind-Blowing Canvas Demos

    The <canvas> element has been a revelation for the visual experts among our ranks.  Canvas provides the means for incredible and efficient animations with the added bonus of no Flash; these developers can flash their awesome JavaScript skills instead.  Here are nine unbelievable canvas demos that...

Incredible Demos

Discussion

    Wrap your code in <pre class="{language}"></pre> tags, link to a GitHub gist, JSFiddle fiddle, or CodePen pen to embed!