Let your documentation be your testing suite.

Write JSDoc style doc examples on all your functions and then test them using doctest-js.

Contents

• Getting Started
  • 1. Install
  • 2. Write @example comments
  • 3. Run the tests
• Advanced
  • Multiple tests
  • Testing classes
• Usage online
• Contributing
• Credits
• Status

npm install @supabase/doctest-js

Create a JSDoc style @example on any functions that you want tested.

/**
 * Returns the sum of 2 numbers
 *
 * @example sum(1, 2)
 * //=> 3
 */
export const sum = (a, b) => {
  return a + b
}

Note that the expected return value must be prefixed by //=>.

Import the doctest function in your test suite and point it at the file.

import doctest from '@supabase/doctest-js';
describe('Doctests', () => {
  // file paths are relative to root of directory
  doctest('src/sum.js')
  doctest('src/someOtherFile.js')
})

You can run multiple tests for the same function.

/**
 * @example sum(1, 2)
 * //=> 3
 * @example sum(3, 4)
 * //=> 7
 */
export const sum = (a, b) => {
  return a + b
}

Testing classes requires you to pass a newed up instance of the class into the test itself. Here is a simple example:

// Arithmetic.js - a basic class which we need to test
class Arithmetic {
  constructor() {}
  /**
   * @example add(1, 2)
   * //=> 3
   */
  add(a, b) {
    return a + b
  }
}
export { Arithmetic }

// Arithmetic.test.js
const { Arithmetic } = require('./Arithmetic.js')
describe('passing doctest', () => {
  doctest('./Arithmetic.js', { instance: new Arithmetic() })
})

See this in the wild:

• supabase/postgrest-js

• Fork the repo on GitHub
• Clone the project to your own machine
• Commit changes to your own branch
• Push your work back up to your fork
• Submit a Pull request so that we can review your changes and merge

• Inspired by Elixir Doctests
• Original fork of mainshayne223/doctest-js. See issue #1.

Ready for production! Watch and star this repo to keep updated on releases.

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