Back to Repositories

Testing Accept Header Processing in Koa Framework

This test suite validates the accept header handling functionality in Koa’s request context. It ensures proper parsing and manipulation of HTTP Accept headers, which are crucial for content negotiation between clients and servers.

Test Coverage Overview

The test coverage focuses on the ctx.accept property implementation and manipulation in Koa’s request context.

Validates Accept instance creation from request headers
Tests accept header replacement functionality
Verifies correct priority ordering of content types
Covers MIME type parsing and preference handling

Implementation Analysis

The testing approach utilizes Node’s native test framework with focused unit tests for Accept header processing. It employs a context helper pattern for test isolation and setup.

Uses node:test for test structure
Implements assert for verification
Leverages test-helpers for context creation
Demonstrates Accept instance manipulation

Technical Details

Testing infrastructure includes:

Node.js native test runner
accepts npm package for header parsing
Custom context test helpers
assert module for assertions
MIME type content negotiation testing

Best Practices Demonstrated

The test suite exemplifies strong testing practices through isolated test cases and comprehensive header validation scenarios.

Isolated test context creation
Clear test case organization
Explicit assertion messages
Comprehensive MIME type handling
Proper test setup and teardown

koajs/koa

__tests__/request/accept.test.js

            
'use strict'

const { describe, it } = require('node:test')
const Accept = require('accepts')
const assert = require('assert')
const context = require('../../test-helpers/context')

describe('ctx.accept', () => {
  it('should return an Accept instance', () => {
    const ctx = context()
    ctx.req.headers.accept = 'application/*;q=0.2, image/jpeg;q=0.8, text/html, text/plain'
    assert(ctx.accept instanceof Accept)
  })
})

describe('ctx.accept=', () => {
  it('should replace the accept object', () => {
    const ctx = context()
    ctx.req.headers.accept = 'text/plain'
    assert.deepStrictEqual(ctx.accepts(), ['text/plain'])

    const request = context.request()
    request.req.headers.accept = 'application/*;q=0.2, image/jpeg;q=0.8, text/html, text/plain'
    ctx.accept = Accept(request.req)
    assert.deepStrictEqual(ctx.accepts(), ['text/html', 'text/plain', 'image/jpeg', 'application/*'])
  })
})