feat!(H2): enable H2 by default

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.
@@ -31,9 +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).

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:') {

lib/dispatcher/client-h2.js

@@ -35,9 +35,6 @@ const kOpenStreams = Symbol('open streams')
 
 let extractBody
 
-// Experimental
-let h2ExperimentalWarned = false
-
 /** @type {import('http2')} */
 let http2
 try {
@@ -82,13 +79,6 @@ 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],

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(
@@ -211,8 +208,7 @@ test(
     const client = new Client(`https://localhost:${server.address().port}`, {
       connect: {
         rejectUnauthorized: false
-      },
-      allowH2: true
+      }
     })
 
     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))

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