fix: Do not response Content-Length if Transfer-Encoding is defined c…

…loses #1562

History.md

@@ -8,6 +8,10 @@
   Generators are no longer supported.
   Koa no longer asserts if generators are used.
 
+## Fixes
+
+- fix: Do not response Content-Length if Transfer-Encoding is defined #1562 @charlyzeng
+
 2.13.1 / 2021-01-04
 ==================
 

__tests__/application/response.js

@@ -12,6 +12,8 @@ describe('app.response', () => {
   const app3 = new Koa()
   const app4 = new Koa()
   const app5 = new Koa()
+  const app6 = new Koa()
+  const app7 = new Koa()
 
   it('should merge properties', () => {
     app1.use((ctx, next) => {
@@ -71,4 +73,28 @@ describe('app.response', () => {
       .get('/')
       .expect(204)
   })
+
+  it('should add Content-Length when Transfer-Encoding is not defined', () => {
+    app6.use((ctx, next) => {
+      ctx.body = 'hello world'
+    })
+
+    return request(app6.listen())
+      .get('/')
+      .expect('Content-Length', '11')
+      .expect(200)
+  })
+
+  it('should not add Content-Length when Transfer-Encoding is defined', () => {
+    app7.use((ctx, next) => {
+      ctx.set('Transfer-Encoding', 'chunked')
+      ctx.body = 'hello world'
+      assert.strictEqual(ctx.response.get('Content-Length'), '')
+    })
+
+    return request(app7.listen())
+      .get('/')
+      .expect('Transfer-Encoding', 'chunked')
+      .expect(200)
+  })
 })

lib/response.js

@@ -191,7 +191,9 @@ module.exports = {
    */
 
   set length (n) {
-    this.set('Content-Length', n)
+    if (!this.has('Transfer-Encoding')) {
+      this.set('Content-Length', n)
+    }
   },
 
   /**