inspector: convert a header object to a simple string dictionary

lib/internal/inspector_network_tracking.js

@@ -1,7 +1,10 @@
 'use strict';
 
 const {
+  ArrayIsArray,
   DateNow,
+  ObjectEntries,
+  String,
 } = primordials;
 
 let dc;
@@ -10,6 +13,25 @@ let Network;
 let requestId = 0;
 const getNextRequestId = () => `node-network-event-${++requestId}`;
 
+// Convert a Headers object (Map<string, number | string | string[]>) to a plain object (Map<string, string>)
+const headerObjectToDictionary = (headers = {}) => {
+  const dict = {};
+  for (const { 0: key, 1: value } of ObjectEntries(headers)) {
+    if (typeof value === 'string') {
+      dict[key] = value;
+    } else if (ArrayIsArray(value)) {
+      if (key.toLowerCase() === 'cookie') dict[key] = value.join('; ');
+      // ChromeDevTools frontend treats 'set-cookie' as a special case
+      // https://github.com/ChromeDevTools/devtools-frontend/blob/4275917f84266ef40613db3c1784a25f902ea74e/front_end/core/sdk/NetworkRequest.ts#L1368
+      else if (key.toLowerCase() === 'set-cookie') dict[key] = value.join('\n');
+      else dict[key] = value.join(', ');
+    } else {
+      dict[key] = String(value);
+    }
+  }
+  return dict;
+};
+
 function onClientRequestStart({ request }) {
   const url = `${request.protocol}//${request.host}${request.path}`;
   const wallTime = DateNow();
@@ -22,7 +44,7 @@ function onClientRequestStart({ request }) {
     request: {
       url,
       method: request.method,
-      headers: request.getHeaders(),
+      headers: headerObjectToDictionary(request.getHeaders()),
     },
   });
 }
@@ -41,7 +63,7 @@ function onClientResponseFinish({ request, response }) {
       url,
       status: response.statusCode,
       statusText: response.statusMessage ?? '',
-      headers: response.headers,
+      headers: headerObjectToDictionary(response.headers),
     },
   });
   Network.loadingFinished({

test/parallel/test-inspector-network-domain.js

@@ -13,10 +13,25 @@ const inspector = require('node:inspector/promises');
 const session = new inspector.Session();
 session.connect();
 
+const requestHeaders = {
+  'accept-language': 'en-US',
+  'Cookie': ['k1=v1', 'k2=v2'],
+  'age': 1000,
+  'x-header1': ['value1', 'value2']
+};
+
+const setResponseHeaders = (res) => {
+  res.setHeader('server', 'node');
+  res.setHeader('etag', 12345);
+  res.setHeader('Set-Cookie', ['key1=value1', 'key2=value2']);
+  res.setHeader('x-header2', ['value1', 'value2']);
+};
+
 const httpServer = http.createServer((req, res) => {
   const path = req.url;
   switch (path) {
     case '/hello-world':
+      setResponseHeaders(res);
       res.writeHead(200);
       res.end('hello world\n');
       break;
@@ -32,6 +47,7 @@ const httpsServer = https.createServer({
   const path = req.url;
   switch (path) {
     case '/hello-world':
+      setResponseHeaders(res);
       res.writeHead(200);
       res.end('hello world\n');
       break;
@@ -53,6 +69,10 @@ const testHttpGet = () => new Promise((resolve, reject) => {
     assert.strictEqual(params.request.url, 'http://127.0.0.1/hello-world');
     assert.strictEqual(params.request.method, 'GET');
     assert.strictEqual(typeof params.request.headers, 'object');
+    assert.strictEqual(params.request.headers['accept-language'], 'en-US');
+    assert.strictEqual(params.request.headers.cookie, 'k1=v1; k2=v2');
+    assert.strictEqual(params.request.headers.age, '1000');
+    assert.strictEqual(params.request.headers['x-header1'], 'value1, value2');
     assert.strictEqual(typeof params.timestamp, 'number');
     assert.strictEqual(typeof params.wallTime, 'number');
   }));
@@ -64,6 +84,10 @@ const testHttpGet = () => new Promise((resolve, reject) => {
     assert.strictEqual(params.response.statusText, 'OK');
     assert.strictEqual(params.response.url, 'http://127.0.0.1/hello-world');
     assert.strictEqual(typeof params.response.headers, 'object');
+    assert.strictEqual(params.response.headers.server, 'node');
+    assert.strictEqual(params.response.headers.etag, '12345');
+    assert.strictEqual(params.response.headers['set-cookie'], 'key1=value1\nkey2=value2');
+    assert.strictEqual(params.response.headers['x-header2'], 'value1, value2');
   }));
   session.on('Network.loadingFinished', common.mustCall(({ params }) => {
     assert.ok(params.requestId.startsWith('node-network-event-'));
@@ -75,6 +99,7 @@ const testHttpGet = () => new Promise((resolve, reject) => {
     host: '127.0.0.1',
     port: httpServer.address().port,
     path: '/hello-world',
+    headers: requestHeaders
   }, common.mustCall());
 });
 
@@ -84,6 +109,10 @@ const testHttpsGet = () => new Promise((resolve, reject) => {
     assert.strictEqual(params.request.url, 'https://127.0.0.1/hello-world');
     assert.strictEqual(params.request.method, 'GET');
     assert.strictEqual(typeof params.request.headers, 'object');
+    assert.strictEqual(params.request.headers['accept-language'], 'en-US');
+    assert.strictEqual(params.request.headers.cookie, 'k1=v1; k2=v2');
+    assert.strictEqual(params.request.headers.age, '1000');
+    assert.strictEqual(params.request.headers['x-header1'], 'value1, value2');
     assert.strictEqual(typeof params.timestamp, 'number');
     assert.strictEqual(typeof params.wallTime, 'number');
   }));
@@ -95,6 +124,10 @@ const testHttpsGet = () => new Promise((resolve, reject) => {
     assert.strictEqual(params.response.statusText, 'OK');
     assert.strictEqual(params.response.url, 'https://127.0.0.1/hello-world');
     assert.strictEqual(typeof params.response.headers, 'object');
+    assert.strictEqual(params.response.headers.server, 'node');
+    assert.strictEqual(params.response.headers.etag, '12345');
+    assert.strictEqual(params.response.headers['set-cookie'], 'key1=value1\nkey2=value2');
+    assert.strictEqual(params.response.headers['x-header2'], 'value1, value2');
   }));
   session.on('Network.loadingFinished', common.mustCall(({ params }) => {
     assert.ok(params.requestId.startsWith('node-network-event-'));
@@ -107,6 +140,7 @@ const testHttpsGet = () => new Promise((resolve, reject) => {
     port: httpsServer.address().port,
     path: '/hello-world',
     rejectUnauthorized: false,
+    headers: requestHeaders,
   }, common.mustCall());
 });