Back to Repositories

Testing Response Inspection Implementation in Koa.js

This test suite validates the response inspection functionality in Koa.js, focusing on the res.inspect() method and its behavior in different scenarios. The tests ensure proper JSON representation of response objects and handle edge cases like missing response objects.

Test Coverage Overview

The test suite provides comprehensive coverage of the response inspection mechanism.

Key areas tested include:

JSON representation of response objects with status, message, headers and body
Edge case handling for missing response.res objects
Integration with Node.js util.inspect functionality

Implementation Analysis

The testing approach uses Node’s built-in test framework with describe/it blocks for structured test organization. The implementation leverages test helpers for context creation and makes extensive use of Node’s assert module for validations.

The tests demonstrate proper isolation of test cases and careful setup of test fixtures.

Technical Details

Testing tools and setup:

Node.js test runner (node:test module)
Custom test helpers for context creation
Node’s built-in assert module
util.inspect for object inspection

Best Practices Demonstrated

The test suite exemplifies several testing best practices:

Proper test isolation and setup
Clear test case organization using describe blocks
Comprehensive edge case coverage
Explicit expected vs actual value comparisons
Use of strict equality assertions

koajs/koa

__tests__/response/inspect.test.js

            
'use strict'

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

describe('res.inspect()', () => {
  describe('with no response.res present', () => {
    it('should return null', () => {
      const res = response()
      res.body = 'hello'
      delete res.res
      assert.strictEqual(res.inspect(), undefined)
      assert.strictEqual(util.inspect(res), 'undefined')
    })
  })

  it('should return a json representation', () => {
    const res = response()
    res.body = 'hello'

    const expected = {
      status: 200,
      message: 'OK',
      header: {
        'content-type': 'text/plain; charset=utf-8',
        'content-length': '5'
      },
      body: 'hello'
    }

    assert.deepStrictEqual(res.inspect(), expected)
    assert.deepStrictEqual(util.inspect(res), util.inspect(expected))
  })
})