fix: throw ERR_HTTP_HEADERS_SENT error after multiple writeHead

Author: marco-ippolito

lib/_http_server.js

@@ -331,6 +331,11 @@ ServerResponse.prototype._implicitHeader = function _implicitHeader() {
 
 ServerResponse.prototype.writeHead = writeHead;
 function writeHead(statusCode, reason, obj) {
+
+  if (this._header) {
+    throw new ERR_HTTP_HEADERS_SENT('writeHead');
+  }
+
   const originalStatusCode = statusCode;
 
   statusCode |= 0;

test/parallel/test-http-write-head-2.js

@@ -59,63 +59,3 @@ const http = require('http');
     }));
   }));
 }
-
-{
-  const server = http.createServer((req, res) => {
-    try {
-      res.writeHead(200,[ 'test', '1' ]);
-      res.writeHead(200,[ 'test2', '2' ]);
-      res.end();
-    } catch (error) {
-      assert.strictEqual(err.code, 'ERR_INVALID_ARG_VALUE');
-    }
-  });
-
-  server.listen(0, () => {
-    http.get({ port: server.address().port }, common.mustCall((res) => {
-      assert.equal('test' in res.headers, false)
-      assert.strictEqual(res.headers.test2, '2');
-      res.resume().on('end', common.mustCall(() => {
-        server.close();
-      }));
-    }));
-  });
-}
-
-{
-  const server = http.createServer((req, res) => {
-    res.writeHead(200,[ 'test', '1' ]);
-    assert.equal(res.getHeader('test'), undefined)
-    res.end();
-  });
-  
-  server.listen(0, () => {
-    http.get({ port: server.address().port }, (res) => {
-      assert.strictEqual(res.headers.test, '1');
-      res.resume().on('end', common.mustCall(() => {
-        server.close();
-      }));
-    });
-  });
-}
-
-{
-  const server = http.createServer((req, res) => {
-    res.setHeader('test2','2')
-    res.writeHead(200,[ 'test', '1' ]);
-    assert.strictEqual(res.getHeader('test'), '1');
-    assert.strictEqual(res.getHeader('test2'), '2');
-    res.end();
-  });
-  
-  server.listen(0, () => {
-    http.get({ port: server.address().port }, (res) => {
-      assert.strictEqual(res.headers.test, '1');
-      assert.strictEqual(res.headers.test2, '2');
-      res.resume().on('end', common.mustCall(() => {
-        server.close();
-      }));
-    });
-  });
-}
-

test/parallel/test-http-write-head.js

@@ -58,7 +58,7 @@ const s = http.createServer(common.mustCall((req, res) => {
   }, {
     code: 'ERR_HTTP_HEADERS_SENT',
     name: 'Error',
-    message: 'Cannot render headers after they are sent to the client'
+    message: 'Cannot writeHead headers after they are sent to the client'
   });
 
   res.end();
@@ -76,3 +76,25 @@ function runTest() {
     response.resume();
   }));
 }
+
+{
+  const server = http.createServer((req, res) => {
+    res.writeHead(200, [ 'test', '1' ]);
+    assert.throws(() => res.writeHead(200, [ 'test2', '2' ]), {
+      code: 'ERR_HTTP_HEADERS_SENT',
+      name: 'Error',
+      message: 'Cannot writeHead headers after they are sent to the client'
+    });
+    res.end();
+  });
+
+  server.listen(0, () => {
+    http.get({ port: server.address().port }, (res) => {
+      assert.strictEqual(res.headers.test, '1');
+      assert.strictEqual('test2' in res.headers, false);
+      res.resume().on('end', common.mustCall(() => {
+        server.close();
+      }));
+    });
+  });
+}