http2: make early hints generic

nodejs · nodejs-github-bot · Oct 6, 2022 · Sep 29, 2022 · Sep 29, 2022 · Sep 29, 2022
commit ca64b81be309c44c794066b8bf10fccb26827fd6
diff --git a/lib/_http_server.js b/lib/_http_server.js
@@ -320,11 +320,56 @@ ServerResponse.prototype.writeEarlyHints = function writeEarlyHints(links, cb) {
     }
 
     head += '\r\n';
+  } else if (typeof links === 'object') {
+    const keys = ObjectKeys(links);
+
+    if (!keys.length) {
+      return;
+    }
+
+    const link = links.link;
+
+    if (typeof link === 'string') {
+      validateLinkHeaderValue(link, 'links');
+      head += 'Link: ' + link + '\r\n';
+    } else if (ArrayIsArray(link)) {
+      const linkLength = link.length;
+      if (!linkLength) {
+        return;
+      }
+
+      head += 'Link: ';
+
+      for (let i = 0; i < linkLength; i++) {
+        validateLinkHeaderValue(link[i], 'links');
+        head += link[i];
+
+        if (i !== linkLength - 1) {
+          head += ', ';
+        }
+      }
+
+      head += '\r\n';
+    } else {
+      throw new ERR_INVALID_ARG_VALUE(
+        'links',
+        links,
+        'must be an array, object or string of format "</styles.css>; rel=preload; as=style"'
+      );
+    }
+
+    for (const key of keys) {
+      if (key === 'link') {
+        continue;
+      }
+
+      head += key + ', ' + keys[key] + '\r\n';
+    }
   } else {
     throw new ERR_INVALID_ARG_VALUE(
       'links',
       links,
-      'must be an array or string of format "</styles.css>; rel=preload; as=style"'
+      'must be an array, object or string of format "</styles.css>; rel=preload; as=style"'
     );
   }
 

diff --git a/lib/internal/http2/compat.js b/lib/internal/http2/compat.js
@@ -848,6 +848,7 @@ class Http2ServerResponse extends Stream {
   }
 
   writeEarlyHints(links) {
+    const headers = ObjectCreate(null);
     let linkHeaderValue = '';
 
     if (typeof links === 'string') {
@@ -869,11 +870,51 @@ class Http2ServerResponse extends Stream {
           linkHeaderValue += ', ';
         }
       }
+    } else if (typeof links === 'object') {
+      const keys = ObjectKeys(links);
+
+      if (!keys.length) {
+        return;
+      }
+
+      const link = links.link;
+
+      if (typeof link === 'string') {
+        validateLinkHeaderValue(link, 'links');
+        linkHeaderValue += link;
+      } else if (ArrayIsArray(link)) {
+        if (!link.length) {
+          return;
+        }
+
+        for (let i = 0; i < link.length; i++) {
+          validateLinkHeaderValue(link[i]);
+          linkHeaderValue += link;
+
+          if (i !== link.length - 1) {
+            linkHeaderValue += ', ';
+          }
+        }
+      } else {
+        throw new ERR_INVALID_ARG_VALUE(
+          'links',
+          links,
+          'must be an array, object or string of format "</styles.css>; rel=preload; as=style"'
+        );
+      }
+
+      for (const key of keys) {
+        if (key === 'link') {
+          continue;
+        }
+
+        headers[key] = keys[key];
+      }
     } else {
       throw new ERR_INVALID_ARG_VALUE(
         'links',
         links,
-        'must be an array or string of format "</styles.css>; rel=preload; as=style"'
+        'must be an array, object or string of format "</styles.css>; rel=preload; as=style"'
       );
     }
 
@@ -884,7 +925,8 @@ class Http2ServerResponse extends Stream {
 
     stream.additionalHeaders({
       [HTTP2_HEADER_STATUS]: HTTP_STATUS_EARLY_HINTS,
-      'Link': linkHeaderValue
+      'Link': linkHeaderValue,
+      ...headers
     });
 
     return true;

diff --git a/test/parallel/test-http-early-hints-invalid-argument-type.js b/test/parallel/test-http-early-hints-invalid-argument-type.js
diff --git a/test/parallel/test-http-early-hints.js b/test/parallel/test-http-early-hints.js
@@ -133,3 +133,89 @@ const testResBody = 'response content\n';
     req.end();
   }));
 }
+
+{
+  // Happy flow - object argument
+
+  const server = http.createServer(common.mustCall((req, res) => {
+    debug('Server sending early hints...');
+    res.writeEarlyHints({
+      'link': '</styles.css>; rel=preload; as=style',
+      'x-trace-id': 'id for diagnostics'
+    });
+
+    debug('Server sending full response...');
+    res.end(testResBody);
+  }));
+
+  server.listen(0, common.mustCall(() => {
+    const req = http.request({
+      port: server.address().port, path: '/'
+    });
+    debug('Client sending request...');
+
+    req.on('information', common.mustCall((res) => {
+      assert.strictEqual(
+        res.headers.link,
+        '</styles.css>; rel=preload; as=style, </scripts.js>; rel=preload; as=script'
+      );
+    }));
+
+    req.on('response', common.mustCall((res) => {
+      let body = '';
+
+      assert.strictEqual(res.statusCode, 200, `Final status code was ${res.statusCode}, not 200.`);
+
+      res.on('data', (chunk) => {
+        body += chunk;
+      });
+
+      res.on('end', common.mustCall(() => {
+        debug('Got full response.');
+        assert.strictEqual(body, testResBody);
+        server.close();
+      }));
+    }));
+
+    req.end();
+  }));
+}
+
+{
+  // Happy flow - empty object
+
+  const server = http.createServer(common.mustCall((req, res) => {
+    debug('Server sending early hints...');
+    res.writeEarlyHints({});
+
+    debug('Server sending full response...');
+    res.end(testResBody);
+  }));
+
+  server.listen(0, common.mustCall(() => {
+    const req = http.request({
+      port: server.address().port, path: '/'
+    });
+    debug('Client sending request...');
+
+    req.on('information', common.mustNotCall());
+
+    req.on('response', common.mustCall((res) => {
+      let body = '';
+
+      assert.strictEqual(res.statusCode, 200, `Final status code was ${res.statusCode}, not 200.`);
+
+      res.on('data', (chunk) => {
+        body += chunk;
+      });
+
+      res.on('end', common.mustCall(() => {
+        debug('Got full response.');
+        assert.strictEqual(body, testResBody);
+        server.close();
+      }));
+    }));
+
+    req.end();
+  }));
+}