doctests-via-ava

doctests (via ava) for javascript and typescript

Installing

npm install doctests-via-ava -D or yarn add doctests-via-ava -D

make sure you have ava installed as well:

npm install ava -D or yarn add ava -D

Usage

Write your comments in normal JS Doc format, but instead of using @example use @doctest or @doctests (either/or), followed by a JS code block of your ava test, EG:

/**
 * sums two numbers
 *
 * @doctests
 * ```js
 * t.is(sum(1, 2), 3)
 * t.is(sum(4, 4), 8)
 * ```
 */
export const sum = (a: number, b: number): number => {
  return a + b;
};

Next, add a script in your package.json:

  "scripts": {
    "doctest": "doctests-via-ava \"./dist/src/**/*.js\" && ava test ./doctests/*.js"
   }

Running yarn doctest (or the npm equivalent) will transform your doctests into regular ava tests, and then run them. Up to you whether to add doctests to .gitignore or not.

We utilize the excellent fast-glob library to find files w/ doctests. What you pass into doctests-via-ava gets directly passed to fast-glob. Be sure to wrap your glob in quotes (eg doctests-via-ava "./src/*.js"), since unix will turn certain globs into a list of files, which the cli does not expect.

All this lib does is transform your doctests into regular ava tests. As such, it can only doctest exported functions (since it needs to import them from the original source). It's also your responsibility to install ava.

For example, the above sum function would compile down to the ava test of:

import test from "ava";
import { sum } from "../dist/src/sum.js";

test("sum", (t) => {
  t.is(sum(1, 2), 3);
  t.is(sum(4, 4), 8);
});

@doctest_only

Use @doctest_only or @doctests_only to only create/run a specific group of doctests.

TypeScript

If you're compiling your TS yourself, simply point the doctests-via-ava CLI command at TS's outDir (see above).

If you're using something like create-react-app that's compiling your TS for you, first follow AVA's instructions for setting up ts-node.

Then, pass in the --ts flag to the doctests-via-ava cli command:

doctests-via-ava "./src/**/*.ts" --ts && ava test ./doctests/*.ts

One gotcha is that ts-node wants you to add a .js ending to your imports, eg import sortBy from 'lodash/sortBy.js'; - which CRA doesn't require (but is harmless to add), so you might see a ERR_MODULE_NOT_FOUND error if missing that in your files with doctests.

Stage of development

This lib is very new, probably buggy, and only really handles the happy path. This will improve over time.

NPM link: https://www.npmjs.com/package/doctests-via-ava

License

MIT