feat: print Listening on messages on stderr instead of stdout (#25491)

Fixes https://github.com/denoland/deno/issues/25114

---------

Signed-off-by: Leo Kettmeir <crowlkats@toaxl.com>
Co-authored-by: Bartek Iwańczuk <biwanczuk@gmail.com>
Co-authored-by: crowlkats <crowlkats@toaxl.com>
Co-authored-by: Nathan Whitaker <17734409+nathanwhit@users.noreply.github.com>

ext/http/00_serve.ts

@@ -646,7 +646,7 @@ function serve(arg1, arg2) {
         options.onListen(listener.addr);
       } else {
         // deno-lint-ignore no-console
-        console.log(`Listening on ${path}`);
+        console.error(`Listening on ${path}`);
       }
     });
   }
@@ -695,7 +695,7 @@ function serve(arg1, arg2) {
       const host = formatHostName(addr.hostname);
 
       // deno-lint-ignore no-console
-      console.log(`Listening on ${scheme}${host}:${addr.port}/`);
+      console.error(`Listening on ${scheme}${host}:${addr.port}/`);
     }
   };
 
@@ -871,7 +871,7 @@ function registerDeclarativeServer(exports) {
             const host = formatHostName(hostname);
 
             // deno-lint-ignore no-console
-            console.debug(
+            console.error(
               `%cdeno serve%c: Listening on %chttp://${host}:${port}/%c${nThreads}`,
               "color: green",
               "color: inherit",

runtime/js/99_main.js

@@ -3,6 +3,7 @@
 // Remove Intl.v8BreakIterator because it is a non-standard API.
 delete Intl.v8BreakIterator;
 
+import * as internalConsole from "ext:deno_console/01_console.js";
 import { core, internals, primordials } from "ext:core/mod.js";
 const ops = core.ops;
 import {
@@ -578,36 +579,19 @@ function bootstrapMainRuntime(runtimeOptions, warmup = false) {
 
     if (mode === executionModes.serve) {
       if (serveIsMain && serveWorkerCount) {
-        // deno-lint-ignore no-console
-        const origLog = console.log;
-        // deno-lint-ignore no-console
-        const origError = console.error;
-        const prefix = `[serve-worker-0 ]`;
-        // deno-lint-ignore no-console
-        console.log = (...args) => {
-          return origLog(prefix, ...new primordials.SafeArrayIterator(args));
-        };
-        // deno-lint-ignore no-console
-        console.error = (...args) => {
-          return origError(prefix, ...new primordials.SafeArrayIterator(args));
-        };
+        // deno-lint-ignore no-global-assign
+        console = new internalConsole.Console((msg, level) =>
+          core.print("[serve-worker-0 ] " + msg, level > 1)
+        );
       } else if (serveWorkerCount !== null) {
-        // deno-lint-ignore no-console
-        const origLog = console.log;
-        // deno-lint-ignore no-console
-        const origError = console.error;
         const base = `serve-worker-${serveWorkerCount + 1}`;
         // 15 = "serve-worker-nn".length, assuming
         // serveWorkerCount < 100
         const prefix = `[${StringPrototypePadEnd(base, 15, " ")}]`;
-        // deno-lint-ignore no-console
-        console.log = (...args) => {
-          return origLog(prefix, ...new primordials.SafeArrayIterator(args));
-        };
-        // deno-lint-ignore no-console
-        console.error = (...args) => {
-          return origError(prefix, ...new primordials.SafeArrayIterator(args));
-        };
+        // deno-lint-ignore no-global-assign
+        console = new internalConsole.Console((msg, level) =>
+          core.print(`${prefix} ` + msg, level > 1)
+        );
       }
     }
 

tests/integration/serve_tests.rs

@@ -61,11 +61,13 @@ impl ServeClientBuilder {
   fn new() -> Self {
     Self(
       util::deno_cmd()
+        .env("NO_COLOR", "1")
         .current_dir(util::testdata_path())
         .arg("serve")
         .arg("--port")
         .arg("0")
-        .stdout_piped(),
+        .stdout_piped()
+        .stderr_piped(),
       None,
     )
   }
@@ -106,12 +108,12 @@ impl ServeClient {
   fn output(self) -> String {
     let mut child = self.child.borrow_mut();
     child.kill().unwrap();
-    let mut stdout = child.stdout.take().unwrap();
+    let mut stderr = child.stderr.take().unwrap();
     child.wait().unwrap();
 
     let mut output_buf = self.output_buf.borrow_mut();
 
-    stdout.read_to_end(&mut output_buf).unwrap();
+    stderr.read_to_end(&mut output_buf).unwrap();
 
     String::from_utf8(std::mem::take(&mut *output_buf)).unwrap()
   }
@@ -128,7 +130,7 @@ impl ServeClient {
     let mut buffer = self.output_buf.borrow_mut();
     let mut temp_buf = [0u8; 64];
     let mut child = self.child.borrow_mut();
-    let stdout = child.stdout.as_mut().unwrap();
+    let stderr = child.stderr.as_mut().unwrap();
     let port_regex = regex::bytes::Regex::new(r":(\d+)").unwrap();
 
     let start = std::time::Instant::now();
@@ -141,7 +143,7 @@ impl ServeClient {
           String::from_utf8_lossy(&buffer)
         );
       }
-      let read = stdout.read(&mut temp_buf).unwrap();
+      let read = stderr.read(&mut temp_buf).unwrap();
       buffer.extend_from_slice(&temp_buf[..read]);
       if let Some(p) = port_regex
         .captures(&buffer)

tests/integration/watcher_tests.rs

@@ -1359,16 +1359,16 @@ async fn test_watch_serve() {
     .piped_output()
     .spawn()
     .unwrap();
-  let (mut stdout_lines, mut stderr_lines) = child_lines(&mut child);
+  let (mut _stdout_lines, mut stderr_lines) = child_lines(&mut child);
 
-  wait_contains("Listening on", &mut stdout_lines).await;
+  wait_contains("Listening on", &mut stderr_lines).await;
   // Note that we start serving very quickly, so we specifically want to wait for this message
   wait_contains(r#"Watching paths: [""#, &mut stderr_lines).await;
 
   file_to_watch.write(file_content);
 
   wait_contains("serving", &mut stderr_lines).await;
-  wait_contains("Listening on", &mut stdout_lines).await;
+  wait_contains("Listening on", &mut stderr_lines).await;
 
   check_alive_then_kill(child);
 }

tests/testdata/serve/parallel.ts

@@ -1,7 +1,7 @@
-console.log("starting serve");
+console.error("starting serve");
 export default {
   fetch(_req: Request) {
-    console.log("serving request");
+    console.error("serving request");
     return new Response("deno serve parallel");
   },
 };

tests/unit/serve_test.ts

@@ -792,8 +792,8 @@ Deno.test(
   async function httpServerDefaultOnListenCallback() {
     const ac = new AbortController();
 
-    const consoleLog = console.log;
-    console.log = (msg) => {
+    const consoleError = console.error;
+    console.error = (msg) => {
       try {
         const match = msg.match(
           /Listening on http:\/\/(localhost|0\.0\.0\.0):(\d+)\//,
@@ -818,7 +818,7 @@ Deno.test(
 
       await server.finished;
     } finally {
-      console.log = consoleLog;
+      console.error = consoleError;
     }
   },
 );
@@ -875,8 +875,8 @@ Deno.test({ permissions: { net: true } }, async function ipv6Hostname() {
   const ac = new AbortController();
   let url = "";
 
-  const consoleLog = console.log;
-  console.log = (msg) => {
+  const consoleError = console.error;
+  console.error = (msg) => {
     try {
       const match = msg.match(/Listening on (http:\/\/(.*?):(\d+)\/)/);
       assert(!!match, `Didn't match ${msg}`);
@@ -897,7 +897,7 @@ Deno.test({ permissions: { net: true } }, async function ipv6Hostname() {
     assert(new URL(url), `Not a valid URL "${url}"`);
     await server.shutdown();
   } finally {
-    console.log = consoleLog;
+    console.error = consoleError;
   }
 });