http: response.setHeaders()

doc/api/http.md

@@ -1953,6 +1953,8 @@ non-string values. However, the non-string values will be converted to strings
 for network transmission. The same response object is returned to the caller,
 to enable call chaining.
 
+> To set multiple header values at once see [`response.setHeaders()`][].
+
 ```js
 response.setHeader('Content-Type', 'text/html');
 ```
@@ -1987,6 +1989,49 @@ header will not yield the expected result. If progressive population of headers
 is desired with potential future retrieval and modification, use
 [`response.setHeader()`][] instead of [`response.writeHead()`][].
 
+### `response.setHeaders(headers)`
+
+<!-- YAML
+added: REPLACEME
+-->
+
+* `headers` {Object|Array}
+* Returns: {http.ServerResponse}
+
+Returns the response object.
+
+Sets multiple header values for implicit headers.
+`headers` may be an `Array` where the keys and values are in the same list.
+It is _not_ a list of tuples. So, the even-numbered offsets are key values,
+and the odd-numbered offsets are the associated values. The array is in the same
+format as `request.rawHeaders`.
+
+```js
+response.setHeaders(['foo', 'bar', 'fizz', 'buzz']);
+```
+
+or
+
+```js
+response.setHeaders({
+  foo: 'bar',
+  fizz: 'buzz',
+});
+```
+
+When headers have been set with [`response.setHeaders()`][], they will be merged
+with any headers passed to [`response.writeHead()`][], with the headers passed
+to [`response.writeHead()`][] given precedence.
+
+```js
+// Returns content-type = text/plain
+const server = http.createServer((req, res) => {
+  res.setHeaders(['Content-Type', 'text/html', 'X-Foo', 'bar']);
+  res.writeHead(200, { 'Content-Type': 'text/plain' });
+  res.end('ok');
+});
+```
+
 ### `response.setTimeout(msecs[, callback])`
 
 <!-- YAML
@@ -3803,6 +3848,7 @@ Set the maximum number of idle HTTP parsers. **Default:** `1000`.
 [`response.end()`]: #responseenddata-encoding-callback
 [`response.getHeader()`]: #responsegetheadername
 [`response.setHeader()`]: #responsesetheadername-value
+[`response.setHeaders()`]: #responsesetheadersheaders
 [`response.socket`]: #responsesocket
 [`response.writableEnded`]: #responsewritableended
 [`response.writableFinished`]: #responsewritablefinished

lib/_http_outgoing.js

@@ -673,6 +673,34 @@ OutgoingMessage.prototype.setHeader = function setHeader(name, value) {
   return this;
 };
 
+OutgoingMessage.prototype.setHeaders = function setHeaders(obj) {
+  if (this._header) {
+    throw new ERR_HTTP_HEADERS_SENT('set');
+  }
+
+  let k;
+  if (ArrayIsArray(obj)) {
+    if (obj.length % 2 !== 0) {
+      throw new ERR_INVALID_ARG_VALUE('headers', obj);
+    }
+
+    for (let n = 0; n < obj.length; n += 2) {
+      k = obj[n + 0];
+      if (k) this.setHeader(k, obj[n + 1]);
+    }
+  } else if (obj) {
+    const keys = ObjectKeys(obj);
+    // Retain for(;;) loop for performance reasons
+    // Refs: https://github.com/nodejs/node/pull/30958
+    for (let i = 0; i < keys.length; i++) {
+      k = keys[i];
+      if (k) this.setHeader(k, obj[k]);
+    }
+  }
+
+  return this;
+};
+
 OutgoingMessage.prototype.appendHeader = function appendHeader(name, value) {
   if (this._header) {
     throw new ERR_HTTP_HEADERS_SENT('append');

lib/_http_server.js

@@ -22,7 +22,6 @@
 'use strict';
 
 const {
-  ArrayIsArray,
   Error,
   MathMin,
   ObjectKeys,
@@ -76,7 +75,6 @@ const {
   ERR_HTTP_INVALID_STATUS_CODE,
   ERR_HTTP_SOCKET_ENCODING,
   ERR_INVALID_ARG_TYPE,
-  ERR_INVALID_ARG_VALUE,
   ERR_INVALID_CHAR
 } = codes;
 const {
@@ -359,28 +357,7 @@ function writeHead(statusCode, reason, obj) {
   let headers;
   if (this[kOutHeaders]) {
     // Slow-case: when progressive API and header fields are passed.
-    let k;
-    if (ArrayIsArray(obj)) {
-      if (obj.length % 2 !== 0) {
-        throw new ERR_INVALID_ARG_VALUE('headers', obj);
-      }
-
-      for (let n = 0; n < obj.length; n += 2) {
-        k = obj[n + 0];
-        if (k) this.setHeader(k, obj[n + 1]);
-      }
-    } else if (obj) {
-      const keys = ObjectKeys(obj);
-      // Retain for(;;) loop for performance reasons
-      // Refs: https://github.com/nodejs/node/pull/30958
-      for (let i = 0; i < keys.length; i++) {
-        k = keys[i];
-        if (k) this.setHeader(k, obj[k]);
-      }
-    }
-    if (k === undefined && this._header) {
-      throw new ERR_HTTP_HEADERS_SENT('render');
-    }
+    this.setHeaders(obj);
     // Only progressive api is used
     headers = this[kOutHeaders];
   } else {

test/parallel/test-http-response-setheaders.js

@@ -0,0 +1,69 @@
+'use strict';
+const common = require('../common');
+const http = require('http');
+const assert = require('assert');
+
+
+{
+  const server = http.createServer({ requireHostHeader: false }, common.mustCall((req, res) => {
+    res.setHeaders(['foo', '1', 'bar', '2' ]);
+    res.writeHead(200);
+    res.end();
+  }));
+
+  server.listen(0, common.mustCall(() => {
+    http.get({ port: server.address().port, headers: [] }, (res) => {
+      assert.strictEqual(res.statusCode, 200);
+      assert.strictEqual(res.headers.foo, '1');
+      assert.strictEqual(res.headers.bar, '2');
+      res.resume().on('end', common.mustCall(() => {
+        server.close();
+      }));
+    });
+  }));
+}
+
+{
+  const server = http.createServer({ requireHostHeader: false }, common.mustCall((req, res) => {
+    res.setHeaders({
+      foo: '1',
+      bar: '2'
+    });
+    res.writeHead(200);
+    res.end();
+  }));
+
+  server.listen(0, common.mustCall(() => {
+    http.get({ port: server.address().port }, (res) => {
+      assert.strictEqual(res.statusCode, 200);
+      assert.strictEqual(res.headers.foo, '1');
+      assert.strictEqual(res.headers.bar, '2');
+      res.resume().on('end', common.mustCall(() => {
+        server.close();
+      }));
+    });
+  }));
+}
+
+{
+  const server = http.createServer({ requireHostHeader: false }, common.mustCall((req, res) => {
+    res.writeHead(200); // headers already sent
+    assert.throws(() => {
+      res.setHeaders({
+        foo: 'bar',
+      });
+    }, {
+      code: 'ERR_HTTP_HEADERS_SENT'
+    });
+    res.end();
+  }));
+
+  server.listen(0, common.mustCall(() => {
+    http.get({ port: server.address().port }, (res) => {
+      assert.strictEqual(res.headers.foo, undefined);
+      res.resume().on('end', common.mustCall(() => {
+        server.close();
+      }));
+    });
+  }));
+}