ts-http-assert

ts-http-assert

TypeScript version of http-assert with Assertion Functions.

Motivation

There are multiple attempts to give the http-assert assertion functions supports:

• https://github.com/DefinitelyTyped/DefinitelyTyped/pull/46014
• https://github.com/DefinitelyTyped/DefinitelyTyped/pull/46698
• https://github.com/DefinitelyTyped/DefinitelyTyped/pull/47557

All of these attemps are failed because @types/koa refers @types/http-assert as methods, and due to https://github.com/microsoft/TypeScript/issues/36931 methods cannot simply have assertion functions.

This package is a drop-in replacement of the http-assert package with:

• better typings, and
• assertion functions support.

Install

npm install ts-http-assert

or

yarn add ts-http-assert

Usage

Just replace all

import assert from 'http-assert'

with

import assert from 'ts-http-assert`

to give the assert function and its child functions better typings.

• All parameter combinations in createHttpError, includes:

  • assert(value, status, message, properties)
  • assert(value, status, message)
  • assert(value, status, properties)
  • assert(value, status)
  • assert(value, message, properties)
  • assert(value, message)
  • assert(value, properties)
  • assert(value)

• assert and assert.ok have assertion signatures to assert the condition is true, for example:

  import { IncomingMessage, ServerResponse } from 'http'
  import assert from 'ts-http-assert'
  
  function controller(req: IncomingMessage, res: ServerResponse): void {
      const authorization = req.headers['authorization']
      // authorization might be string | string[] | undefined
      assert(typeof authorization === 'string', 401)
      // or `assert.ok(typeof authorization === 'string', 401)`
  
      // It's OK to call the following `authorization.split` because authorization
      // is asserted to be string in the above line.
      const [method, credentials] = authorization.split(' ', 2)
      res.end(`You are in ${method} authorization.`)
  }
  

• assert.strictEqual has assertion signature to assert to 2 values are of the same type, for example:

  import { IncomingMessage, ServerResponse } from 'http'
  import assert from 'ts-http-assert'
  
  function controller(req: IncomingMessage, res: ServerResponse): void {
      const contentType = req.headers['content-type']
      assert.strictEqual(contentType, 'application/json')
  
      // Now the contentType is asserted to be of type string
      res.end(`You submitted in type ${contentType.splice('/')[1]}`)
  }
  

License

MIT