TrimKit

TrimKit is a set of DOM and API abstractions for the purpose of better Javascript minification. For example:

if (a === undefined) { alert('Oops'); }

minifies down to:

if(a===void 0){alert('Oops')}

If we compare against undefined more than 3 times, we can save bytes by doing this:

function isUndefined(a) { return a === void 0; }

if (isUndefined(a)) { alert('Oops'); }

which minifies down to:

function b(a){return a===void 0}

if (b(a)){alert('Oops');}

With enough uses of common APIs, you can win back some bytes.

NOTE: TrimKit will help you obsess about Javascript file sizes but that does not always translate to smaller files after you apply compression. Because files using have more entropy, small, pre-compression gains can result in post-compression losses. YMMV.

Abstractions

• undefined
• requestAnimationFrame
• Array.isArray
• Array.from
• Object.keys
• document
• typeof obj === 'function'
• typeof obj === 'string'
• typeof obj === 'number'
• null
• obj === undefined
• obj === null
• fn.apply(context, params)

Credit

Created by Timothy Farrell