From b18831fad25ff71c1ef763a92839370a0040b979 Mon Sep 17 00:00:00 2001
From: Carlos Fuentes <me@metcoder.dev>
Date: Fri, 8 Nov 2024 11:10:42 +0000
Subject: [PATCH 1/3] feat!(H2): enable H2 by default

---
 docs/docs/api/Client.md     |  2 -
 lib/core/connect.js         |  2 +-
 lib/dispatcher/client-h2.js | 10 -----
 test/fetch/http2.js         | 37 +++++++-----------
 test/http2-alpn.js          |  6 +--
 test/http2.js               | 77 ++++++++++++-------------------------
 6 files changed, 42 insertions(+), 92 deletions(-)

diff --git a/docs/docs/api/Client.md b/docs/docs/api/Client.md
index 0be99625d2e..463cde0a247 100644
--- a/docs/docs/api/Client.md
+++ b/docs/docs/api/Client.md
@@ -17,8 +17,6 @@ Returns: `Client`
 
 ### Parameter: `ClientOptions`
 
-> ⚠️ Warning: The `H2` support is experimental.
-
 * **bodyTimeout** `number | null` (optional) - Default: `300e3` - The timeout after which a request will time out, in milliseconds. Monitors time between receiving body data. Use `0` to disable it entirely. Defaults to 300 seconds. Please note the `timeout` will be reset if you keep writing data to the socket everytime.
 * **headersTimeout** `number | null` (optional) - Default: `300e3` - The amount of time, in milliseconds, the parser will wait to receive the complete HTTP headers while not sending the request. Defaults to 300 seconds.
 * **keepAliveMaxTimeout** `number | null` (optional) - Default: `600e3` - The maximum allowed `keepAliveTimeout`, in milliseconds, when overridden by *keep-alive* hints from the server. Defaults to 10 minutes.
diff --git a/lib/core/connect.js b/lib/core/connect.js
index 8ab21fcd5fc..f252a156834 100644
--- a/lib/core/connect.js
+++ b/lib/core/connect.js
@@ -84,7 +84,7 @@ function buildConnector ({ allowH2, maxCachedSessions, socketPath, timeout, sess
   const options = { path: socketPath, ...opts }
   const sessionCache = new SessionCache(maxCachedSessions == null ? 100 : maxCachedSessions)
   timeout = timeout == null ? 10e3 : timeout
-  allowH2 = allowH2 != null ? allowH2 : false
+  allowH2 = allowH2 != null ? allowH2 : true
   return function connect ({ hostname, host, protocol, port, servername, localAddress, httpSocket }, callback) {
     let socket
     if (protocol === 'https:') {
diff --git a/lib/dispatcher/client-h2.js b/lib/dispatcher/client-h2.js
index ef6d47a0c9c..770083aa935 100644
--- a/lib/dispatcher/client-h2.js
+++ b/lib/dispatcher/client-h2.js
@@ -32,9 +32,6 @@ const {
 
 const kOpenStreams = Symbol('open streams')
 
-// Experimental
-let h2ExperimentalWarned = false
-
 /** @type {import('http2')} */
 let http2
 try {
@@ -79,13 +76,6 @@ function parseH2Headers (headers) {
 async function connectH2 (client, socket) {
   client[kSocket] = socket
 
-  if (!h2ExperimentalWarned) {
-    h2ExperimentalWarned = true
-    process.emitWarning('H2 support is experimental, expect them to change at any time.', {
-      code: 'UNDICI-H2'
-    })
-  }
-
   const session = http2.connect(client[kUrl], {
     createConnection: () => socket,
     peerMaxConcurrentStreams: client[kMaxConcurrentStreams]
diff --git a/test/fetch/http2.js b/test/fetch/http2.js
index f64756de788..eb44a24b2b4 100644
--- a/test/fetch/http2.js
+++ b/test/fetch/http2.js
@@ -42,8 +42,7 @@ test('[Fetch] Issue#2311', async (t) => {
   const client = new Client(`https://localhost:${server.address().port}`, {
     connect: {
       rejectUnauthorized: false
-    },
-    allowH2: true
+    }
   })
 
   const response = await fetch(
@@ -91,8 +90,7 @@ test('[Fetch] Simple GET with h2', async (t) => {
   const client = new Client(`https://localhost:${server.address().port}`, {
     connect: {
       rejectUnauthorized: false
-    },
-    allowH2: true
+    }
   })
 
   const response = await fetch(
@@ -150,8 +148,7 @@ test('[Fetch] Should handle h2 request with body (string or buffer)', async (t)
   const client = new Client(`https://localhost:${server.address().port}`, {
     connect: {
       rejectUnauthorized: false
-    },
-    allowH2: true
+    }
   })
 
   const response = await fetch(
@@ -208,12 +205,11 @@ test(
     server.listen(0)
     await once(server, 'listening')
 
-    const client = new Client(`https://localhost:${server.address().port}`, {
-      connect: {
-        rejectUnauthorized: false
-      },
-      allowH2: true
-    })
+  const client = new Client(`https://localhost:${server.address().port}`, {
+    connect: {
+      rejectUnauthorized: false
+    }
+  })
 
     t.after(closeClientAndServerAsPromise(client, server))
 
@@ -273,8 +269,7 @@ test('Should handle h2 request with body (Blob)', { skip: !Blob }, async (t) =>
   const client = new Client(`https://localhost:${server.address().port}`, {
     connect: {
       rejectUnauthorized: false
-    },
-    allowH2: true
+    }
   })
 
   t.after(closeClientAndServerAsPromise(client, server))
@@ -305,7 +300,7 @@ test('Should handle h2 request with body (Blob)', { skip: !Blob }, async (t) =>
 test(
   'Should handle h2 request with body (Blob:ArrayBuffer)',
   { skip: !Blob },
-  async (t) => {
+  async t => {
     const server = createSecureServer(pem)
     const expectedBody = 'hello'
     const requestChunks = []
@@ -339,8 +334,7 @@ test(
     const client = new Client(`https://localhost:${server.address().port}`, {
       connect: {
         rejectUnauthorized: false
-      },
-      allowH2: true
+      }
     })
 
     t.after(closeClientAndServerAsPromise(client, server))
@@ -386,8 +380,7 @@ test('Issue#2415', async (t) => {
   const client = new Client(`https://localhost:${server.address().port}`, {
     connect: {
       rejectUnauthorized: false
-    },
-    allowH2: true
+    }
   })
 
   const response = await fetch(
@@ -438,8 +431,7 @@ test('Issue #2386', async (t) => {
   const client = new Client(`https://localhost:${server.address().port}`, {
     connect: {
       rejectUnauthorized: false
-    },
-    allowH2: true
+    }
   })
 
   t.after(closeClientAndServerAsPromise(client, server))
@@ -488,8 +480,7 @@ test('Issue #3046', async (t) => {
   const client = new Client(`https://localhost:${server.address().port}`, {
     connect: {
       rejectUnauthorized: false
-    },
-    allowH2: true
+    }
   })
 
   t.after(closeClientAndServerAsPromise(client, server))
diff --git a/test/http2-alpn.js b/test/http2-alpn.js
index 590f65e128e..74a095fc199 100644
--- a/test/http2-alpn.js
+++ b/test/http2-alpn.js
@@ -58,8 +58,7 @@ test('Should upgrade to HTTP/2 when HTTPS/1 is available for GET', async (t) =>
     connect: {
       ca,
       servername: 'agent1'
-    },
-    allowH2: true
+    }
   })
 
   // close the client on teardown
@@ -205,8 +204,7 @@ test('Should upgrade to HTTP/2 when HTTPS/1 is available for POST', async (t) =>
     connect: {
       ca,
       servername: 'agent1'
-    },
-    allowH2: true
+    }
   })
 
   // close the client on teardown
diff --git a/test/http2.js b/test/http2.js
index 83ea5f62cbf..a88bb4f83c9 100644
--- a/test/http2.js
+++ b/test/http2.js
@@ -35,8 +35,7 @@ test('Should support H2 connection', async t => {
   const client = new Client(`https://localhost:${server.address().port}`, {
     connect: {
       rejectUnauthorized: false
-    },
-    allowH2: true
+    }
   })
 
   t = tspl(t, { plan: 6 })
@@ -87,8 +86,7 @@ test('Should support H2 connection(multiple requests)', async t => {
   const client = new Client(`https://localhost:${server.address().port}`, {
     connect: {
       rejectUnauthorized: false
-    },
-    allowH2: true
+    }
   })
 
   t = tspl(t, { plan: 21 })
@@ -142,8 +140,7 @@ test('Should support H2 connection (headers as array)', async t => {
   const client = new Client(`https://localhost:${server.address().port}`, {
     connect: {
       rejectUnauthorized: false
-    },
-    allowH2: true
+    }
   })
 
   t = tspl(t, { plan: 7 })
@@ -190,8 +187,7 @@ test('Should support H2 connection(POST Buffer)', async t => {
   const client = new Client(`https://localhost:${server.address().port}`, {
     connect: {
       rejectUnauthorized: false
-    },
-    allowH2: true
+    }
   })
 
   t = tspl(t, { plan: 6 })
@@ -237,7 +233,6 @@ test('Should throw if bad maxConcurrentStreams has been passed', async t => {
   try {
     // eslint-disable-next-line
     new Client('https://localhost:1000', {
-      allowH2: true,
       maxConcurrentStreams: {}
     })
     t.fail()
@@ -251,7 +246,6 @@ test('Should throw if bad maxConcurrentStreams has been passed', async t => {
   try {
     // eslint-disable-next-line
     new Client('https://localhost:1000', {
-      allowH2: true,
       maxConcurrentStreams: -1
     })
     t.fail()
@@ -375,8 +369,7 @@ test('Should handle h2 continue', async t => {
     connect: {
       rejectUnauthorized: false
     },
-    expectContinue: true,
-    allowH2: true
+    expectContinue: true
   })
 
   after(() => server.close())
@@ -425,8 +418,7 @@ test('Dispatcher#Stream', async t => {
     const client = new Client(`https://localhost:${server.address().port}`, {
       connect: {
         rejectUnauthorized: false
-      },
-      allowH2: true
+      }
     })
 
     after(() => server.close())
@@ -476,8 +468,7 @@ test('Dispatcher#Pipeline', async t => {
     const client = new Client(`https://localhost:${server.address().port}`, {
       connect: {
         rejectUnauthorized: false
-      },
-      allowH2: true
+      }
     })
 
     after(() => server.close())
@@ -537,8 +528,7 @@ test('Dispatcher#Connect', async t => {
     const client = new Client(`https://localhost:${server.address().port}`, {
       connect: {
         rejectUnauthorized: false
-      },
-      allowH2: true
+      }
     })
 
     after(() => server.close())
@@ -586,8 +576,7 @@ test('Dispatcher#Upgrade', async t => {
     const client = new Client(`https://localhost:${server.address().port}`, {
       connect: {
         rejectUnauthorized: false
-      },
-      allowH2: true
+      }
     })
 
     after(() => server.close())
@@ -617,8 +606,7 @@ test('Dispatcher#destroy', async t => {
   const client = new Client(`https://localhost:${server.address().port}`, {
     connect: {
       rejectUnauthorized: false
-    },
-    allowH2: true
+    }
   })
 
   t = tspl(t, { plan: 4 })
@@ -706,8 +694,7 @@ test('Should handle h2 request without body', async t => {
   const client = new Client(`https://localhost:${server.address().port}`, {
     connect: {
       rejectUnauthorized: false
-    },
-    allowH2: true
+    }
   })
 
   after(() => server.close())
@@ -757,8 +744,7 @@ test('Should handle h2 request with body (string or buffer) - dispatch', async t
     const client = new Client(`https://localhost:${server.address().port}`, {
       connect: {
         rejectUnauthorized: false
-      },
-      allowH2: true
+      }
     })
 
     after(() => server.close())
@@ -844,8 +830,7 @@ test('Should handle h2 request with body (stream)', async t => {
   const client = new Client(`https://localhost:${server.address().port}`, {
     connect: {
       rejectUnauthorized: false
-    },
-    allowH2: true
+    }
   })
 
   after(() => server.close())
@@ -911,8 +896,7 @@ test('Should handle h2 request with body (iterable)', async t => {
   const client = new Client(`https://localhost:${server.address().port}`, {
     connect: {
       rejectUnauthorized: false
-    },
-    allowH2: true
+    }
   })
 
   after(() => server.close())
@@ -973,8 +957,7 @@ test('Should handle h2 request with body (Blob)', { skip: !Blob }, async t => {
   const client = new Client(`https://localhost:${server.address().port}`, {
     connect: {
       rejectUnauthorized: false
-    },
-    allowH2: true
+    }
   })
 
   after(() => server.close())
@@ -1039,8 +1022,7 @@ test(
     const client = new Client(`https://localhost:${server.address().port}`, {
       connect: {
         rejectUnauthorized: false
-      },
-      allowH2: true
+      }
     })
 
     after(() => server.close())
@@ -1090,8 +1072,7 @@ test('Agent should support H2 connection', async t => {
   const client = new Agent({
     connect: {
       rejectUnauthorized: false
-    },
-    allowH2: true
+    }
   })
 
   t = tspl(t, { plan: 6 })
@@ -1147,8 +1128,7 @@ test('Should provide pseudo-headers in proper order', async t => {
   const client = new Client(`https://localhost:${server.address().port}`, {
     connect: {
       rejectUnauthorized: false
-    },
-    allowH2: true
+    }
   })
 
   after(() => server.close())
@@ -1182,8 +1162,7 @@ test('The h2 pseudo-headers is not included in the headers', async t => {
   const client = new Client(`https://localhost:${server.address().port}`, {
     connect: {
       rejectUnauthorized: false
-    },
-    allowH2: true
+    }
   })
 
   t = tspl(t, { plan: 2 })
@@ -1214,8 +1193,7 @@ test('Should throw informational error on half-closed streams (remote)', async t
   const client = new Client(`https://localhost:${server.address().port}`, {
     connect: {
       rejectUnauthorized: false
-    },
-    allowH2: true
+    }
   })
 
   t = tspl(t, { plan: 4 })
@@ -1264,8 +1242,7 @@ test('#2364 - Concurrent aborts', async t => {
   const client = new Client(`https://localhost:${server.address().port}`, {
     connect: {
       rejectUnauthorized: false
-    },
-    allowH2: true
+    }
   })
 
   t = tspl(t, { plan: 10 })
@@ -1382,8 +1359,7 @@ test('#2364 - Concurrent aborts (2nd variant)', async t => {
   const client = new Client(`https://localhost:${server.address().port}`, {
     connect: {
       rejectUnauthorized: false
-    },
-    allowH2: true
+    }
   })
 
   t = tspl(t, { plan: 10 })
@@ -1488,8 +1464,7 @@ test('#3046 - GOAWAY Frame', async t => {
   const client = new Client(`https://localhost:${server.address().port}`, {
     connect: {
       rejectUnauthorized: false
-    },
-    allowH2: true
+    }
   })
 
   t = tspl(t, { plan: 7 })
@@ -1542,8 +1517,7 @@ test('#3671 - Graceful close', async (t) => {
   const client = new Client(`https://localhost:${server.address().port}`, {
     connect: {
       rejectUnauthorized: false
-    },
-    allowH2: true
+    }
   })
 
   t = tspl(t, { plan: 5 })
@@ -1605,8 +1579,7 @@ test('#3753 - Handle GOAWAY Gracefully', async (t) => {
     connect: {
       rejectUnauthorized: false
     },
-    pipelining: 2,
-    allowH2: true
+    pipelining: 2
   })
 
   t = tspl(t, { plan: 30 })

From e3c9dfd2eea2cef81497e962d2de3f20d57962fd Mon Sep 17 00:00:00 2001
From: Carlos Fuentes <me@metcoder.dev>
Date: Fri, 8 Nov 2024 11:14:31 +0000
Subject: [PATCH 2/3] fix: lint

---
 test/fetch/http2.js | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/test/fetch/http2.js b/test/fetch/http2.js
index eb44a24b2b4..ef026eaec3b 100644
--- a/test/fetch/http2.js
+++ b/test/fetch/http2.js
@@ -205,11 +205,11 @@ test(
     server.listen(0)
     await once(server, 'listening')
 
-  const client = new Client(`https://localhost:${server.address().port}`, {
-    connect: {
-      rejectUnauthorized: false
-    }
-  })
+    const client = new Client(`https://localhost:${server.address().port}`, {
+      connect: {
+        rejectUnauthorized: false
+      }
+    })
 
     t.after(closeClientAndServerAsPromise(client, server))
 

From 4a439ba36854d1fb33f60064e2330df72525f907 Mon Sep 17 00:00:00 2001
From: Carlos Fuentes <me@metcoder.dev>
Date: Fri, 22 Nov 2024 10:57:00 +0100
Subject: [PATCH 3/3] docs: adjust documentation

---
 docs/docs/api/Client.md | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/docs/docs/api/Client.md b/docs/docs/api/Client.md
index 0fb3519045a..cd7bf14037d 100644
--- a/docs/docs/api/Client.md
+++ b/docs/docs/api/Client.md
@@ -29,9 +29,20 @@ Returns: `Client`
 * **strictContentLength** `Boolean` (optional) - Default: `true` - Whether to treat request content length mismatches as errors. If true, an error is thrown when the request content-length header doesn't match the length of the request body.
 * **autoSelectFamily**: `boolean` (optional) - Default: depends on local Node version, on Node 18.13.0 and above is `false`. Enables a family autodetection algorithm that loosely implements section 5 of [RFC 8305](https://tools.ietf.org/html/rfc8305#section-5). See [here](https://nodejs.org/api/net.html#socketconnectoptions-connectlistener) for more details. This option is ignored if not supported by the current Node version.
 * **autoSelectFamilyAttemptTimeout**: `number` - Default: depends on local Node version, on Node 18.13.0 and above is `250`. The amount of time in milliseconds to wait for a connection attempt to finish before trying the next address when using the `autoSelectFamily` option. See [here](https://nodejs.org/api/net.html#socketconnectoptions-connectlistener) for more details.
-* **allowH2**: `boolean` - Default: `false`. Enables support for H2 if the server has assigned bigger priority to it through ALPN negotiation.
+* **allowH2**: `boolean` - Default: `true`. Enables support for H2 if the server has assigned bigger priority to it through ALPN negotiation.
 * **maxConcurrentStreams**: `number` - Default: `100`. Dictates the maximum number of concurrent streams for a single H2 session. It can be overridden by a SETTINGS remote frame.
 
+> **Notes about HTTP/2**
+> - It only works under TLS connections. h2c is not supported.
+> - The server must support HTTP/2 and choose it as the protocol during the ALPN negotiation.
+>   - The server must not have a bigger priority for HTTP/1.1 than HTTP/2.
+> - Pseudo headers are automatically attached to the request. If you try to set them, they will be overwritten.
+>   - The `:path` header is automatically set to the request path.
+>   - The `:method` header is automatically set to the request method.
+>   - The `:scheme` header is automatically set to the request scheme.
+>   - The `:authority` header is automatically set to the request `host[:port]`.
+> - `PUSH` frames are yet not supported.
+
 #### Parameter: `ConnectOptions`
 
 Every Tls option, see [here](https://nodejs.org/api/tls.html#tls_tls_connect_options_callback).