cli: handle -v/--version in the node argv0 shim

src/runtime/cli/mod.rs

@@ -1524,6 +1524,19 @@
     #[cold]
     #[inline(never)]
     fn exec_run_as_node(log: &mut bun_ast::Log) -> CmdResult {
+        // `node -v` / `node --version`: print `process.version` and exit 0,
+        // matching Node.js. Must run before `init()` because `RUN_TABLE` has no
+        // `-v`/`--version` entry, so clap would reject `-v` and drop
+        // `--version`. Stop at the first positional or `--` so a script's own
+        // `--version` flag is left alone (`node app.js --version`).
+        for a in bun::argv().iter().skip(1) {
+            match a {
+                b"-v" | b"--version" => print_node_version_and_exit(),
+                b"--" => break,
+                _ if a.first() != Some(&b'-') => break,
+                _ => {}
+            }
+        }
         let ctx = init(Tag::RunAsNodeCommand, log)?;
         run_command::RunCommand::exec_as_if_node(ctx)
     }
@@ -2305,3 +2318,14 @@
     Output::flush();
     Global::exit(0);
 }
+
+#[cold]
+pub fn print_node_version_and_exit() -> ! {
+    let w = Output::writer();
+    let _ = w.write_all(
+        const_format::concatcp!("v", bun_core::Environment::REPORTED_NODEJS_VERSION, "\n")
+            .as_bytes(),
+    );
+    Output::flush();
+    Global::exit(0);
+}

test/cli/run/as-node.test.ts

@@ -87,6 +87,38 @@ describe("fake node cli", () => {
     expect(fakeNodeRun(temp, ["-e", "console.log('pass')"]).stdout).toBe("pass");
   });
 
+  describe("-v / --version", () => {
+    // Engine-version preflights (node-gyp, prepare/postinstall scripts) run
+    // `node --version` through the bun-node shim; it must behave like Node.js
+    // and print `v<process.version>` with exit 0.
+    test.each(["-v", "--version"])("node %s prints process.version", flag => {
+      const temp = tempDirWithFiles("fake-node", {});
+      const result = Bun.spawnSync([bunExe(), "--bun", "node", flag], {
+        cwd: temp,
+        env: { ...bunEnv, NODE_ENV: undefined },
+        stdin: Buffer.alloc(0),
+      });
+      expect(result.stderr.toString()).toBe("");
+      expect(result.stdout.toString()).toBe(process.version + "\n");
+      expect(result.exitCode).toBe(0);
+    });
+
+    test("node --version matches node -e 'console.log(process.version)'", () => {
+      const temp = tempDirWithFiles("fake-node", {});
+      const evaled = fakeNodeRun(temp, ["-e", "console.log(process.version)"]).stdout;
+      expect(fakeNodeRun(temp, ["--version"]).stdout).toBe(evaled);
+      expect(fakeNodeRun(temp, ["-v"]).stdout).toBe(evaled);
+    });
+
+    test("node script.js --version passes the flag through to the script", () => {
+      const temp = tempDirWithFiles("fake-node", {
+        "index.js": "console.log(JSON.stringify(process.argv.slice(2)))",
+      });
+      expect(fakeNodeRun(temp, ["index.js", "--version"]).stdout).toBe(JSON.stringify(["--version"]));
+      expect(fakeNodeRun(temp, ["index.js", "-v"]).stdout).toBe(JSON.stringify(["-v"]));
+    });
+  });
+
   test("process args work", () => {
     const temp = tempDirWithFiles("fake-node", {
       "index.js": "console.log(JSON.stringify(process.argv.slice(1)))",