fix: improve body null check (#1814)

__tests__/application/respond.js

@@ -501,6 +501,42 @@ describe('app.respond', () => {
  })
  })
 
+ describe('when .body is undefined', () => {
+ it('should respond 204 by default', async () => {
+ const app = new Koa()
+
+ app.use(ctx => {
+ ctx.body = undefined
+ })
+
+ const server = app.listen()
+
+ const res = await request(server)
+ .get('/')
+ .expect(204)
+ .expect('')
+
+ assert.strictEqual(Object.prototype.hasOwnProperty.call(res.headers, 'Content-Type'), false)
+ })
+
+ it('should respond 204 with status=200', async () => {
+ const app = new Koa()
+ app.use(ctx => {
+ ctx.status = 200
+ ctx.body = undefined
+ })
+
+ const server = app.listen()
+
+ const res = await request(server)
+ .get('/')
+ .expect(204)
+ .expect('')
+
+ assert.strictEqual(Object.prototype.hasOwnProperty.call(res.headers, 'Content-Type'), false)
+ })
+ })
+
  describe('when .body is a string', () => {
  it('should respond', () => {
  const app = new Koa()

lib/application.js

@@ -280,7 +280,7 @@ function respond (ctx) {
  }
 
  // status body
- if (body == null) {
+ if (body === null || body === undefined) {
  if (ctx.response._explicitNullBody) {
  ctx.response.remove('Content-Type')
  ctx.response.remove('Transfer-Encoding')