Simpler Typescript Classes

Scenario

We need a minimal Typescript class that will store the median of a set of numbers:

The Power of the Simplest Possible Example

Approach

The file Median.ts contains the class.

import { median } from './median';
export class Median {
result: number = undefined;
    constructor(arr: number[]) {
        this.result = median(arr);
    }
}

The function computing the median is contained in median.ts . See the demo:

https://stackblitz.com/edit/typescript-2njmx7

Demo

Notice that we have broken off the function median from the class. This allows us to:

• Easily place the function in a utility library if it’s reused outside of the context of the class.
• View the class in a more minimal uncluttered form
• Code tests that are smaller and more focused

Practical Unit Testing