cli: handle -v/--version in the node argv0 shim by robobun · Pull Request #36128 · oven-sh/bun

robobun · 2026-07-27T17:54:58Z

What

node -v and node --version now print v<process.version> and exit 0 when bun is invoked through its node argv0 shim (the /tmp/bun-node-<rev>/node symlink that bun run/--bun put on PATH).

Repro

With no real node on PATH:

cat > package.json <<'JSON'
{"scripts":{"probe":"node -e 'console.log(process.version)'; node --version; echo rc1=$?; node -v >/dev/null 2>&1; echo rc2=$?"}}
JSON
PATH=/usr/bin:/bin bun run probe

Before:

v26.3.0
error: Missing script to execute. Bun's provided 'node' cli wrapper does not support a repl.
rc1=1
rc2=1

After:

v26.3.0
v26.3.0
rc1=0
rc2=0

Cause

RunAsNodeCommand parses argv with RUN_TABLE, which has no -v/--version entry (those live in AUTO_ONLY_PARAMS). So:

--version was an unknown long flag, silently dropped (node-mode clears WARN_ON_UNRECOGNIZED_FLAG), leaving ctx.positionals empty and hitting exec_as_if_node_missing_script() → error: Missing script to execute (rc 1).
-v was an unknown short flag, which clap's short-flag chainer hard-rejects (streaming.rs::chainging) → error: Invalid Argument '-v' plus the full bun run usage screen (rc 1).

This broke engine-version preflights (node --version in prepare/postinstall/CI scripts, node-gyp's version probe) on machines without a real node installed, while node -e/-p/file.js through the same shim worked fine.

Fix

Scan argv in exec_run_as_node before init() runs clap: if -v/--version appears before the first positional (or --), print v<REPORTED_NODEJS_VERSION>\n and exit 0. node app.js --version is unaffected; the flag still reaches the script.

Tests

Added to test/cli/run/as-node.test.ts:

node -v / node --version print process.version with exit 0
the shim's output matches node -e 'console.log(process.version)'
node script.js --version still passes --version through to the script

USE_SYSTEM_BUN=1 bun test test/cli/run/as-node.test.ts -t version   # 3 fail, 1 pass
bun bd test test/cli/run/as-node.test.ts                            # 15 pass

[review] gate passed · iteration 0 · 2 files touched

fails on main (without fix)

ASAN without fix: 3 FAILED
$ BUN_DEBUG_QUIET_LOGS=1 bun scripts/build.ts --profile=debug --quiet test "--reporter=junit" "--reporter-outfile=/tmp/mechgate.xml" test/cli/run/as-node.test.ts
bun test v1.4.0 (fea90e29b)

test/cli/run/as-node.test.ts:
(pass) fake node cli > the node cli actually works [411.52ms]
(pass) fake node cli > doesnt resolve bins [390.23ms]
(pass) fake node cli > doesnt resolve scripts [401.47ms]
(pass) fake node cli > can run a script named run.js [396.59ms]
(pass) fake node cli > entrypoint file extension picking > picks tsx over any other ext [407.89ms]
(pass) fake node cli > entrypoint file extension picking > picks jsx over ts [392.87ms]
(pass) fake node cli > entrypoint file extension picking > picks mts over ts [405.56ms]
(pass) fake node cli > entrypoint file extension picking > picks ts over js/cjs/etc [399.19ms]
(pass) fake node cli > node -e  [394.95ms]
 96 |       const result = Bun.spawnSync([bunExe(), "--bun", "node", flag], {
 97 |         cwd: temp,
 98 |         env: { ...bunEnv, NODE_ENV: undefined },
 99 |         stdin: Buffer.alloc(0),
100 |       });
101 |       expect(result.stderr.toString()).toBe("");
                                             ^
... (truncated)

release without fix: 3 FAILED
bun test v1.4.0-canary.1 (1498d7b77)

test/cli/run/as-node.test.ts:
(pass) fake node cli > the node cli actually works [21.91ms]
(pass) fake node cli > doesnt resolve bins [18.35ms]
(pass) fake node cli > doesnt resolve scripts [17.33ms]
(pass) fake node cli > can run a script named run.js [16.93ms]
(pass) fake node cli > entrypoint file extension picking > picks tsx over any other ext [17.38ms]
(pass) fake node cli > entrypoint file extension picking > picks jsx over ts [16.90ms]
(pass) fake node cli > entrypoint file extension picking > picks mts over ts [17.95ms]
(pass) fake node cli > entrypoint file extension picking > picks ts over js/cjs/etc [16.89ms]
(pass) fake node cli > node -e  [13.61ms]
 96 |       const result = Bun.spawnSync([bunExe(), "--bun", "node", flag], {
 97 |         cwd: temp,
 98 |         env: { ...bunEnv, NODE_ENV: undefined },
 99 |         stdin: Buffer.alloc(0),
100 |       });
101 |       expect(result.stderr.toString()).toBe("");
                                             ^
error: expect(received).toBe(expected)

- ""
+ "error: Invalid Argument '-v'
+ error: "node" exited with code 1
+ "

- Expected  - 1
+ Received  + 3

      at <a
... (truncated)

passes on PR (with fix)

ASAN with fix: all passed
$ BUN_DEBUG_QUIET_LOGS=1 bun scripts/build.ts --profile=debug --quiet test "--reporter=junit" "--reporter-outfile=/tmp/mechgate.xml" test/cli/run/as-node.test.ts
bun test v1.4.0 (fea90e29b)

test/cli/run/as-node.test.ts:
(pass) fake node cli > the node cli actually works [404.00ms]
(pass) fake node cli > doesnt resolve bins [376.78ms]
(pass) fake node cli > doesnt resolve scripts [388.46ms]
(pass) fake node cli > can run a script named run.js [397.33ms]
(pass) fake node cli > entrypoint file extension picking > picks tsx over any other ext [403.36ms]
(pass) fake node cli > entrypoint file extension picking > picks jsx over ts [397.51ms]
(pass) fake node cli > entrypoint file extension picking > picks mts over ts [382.50ms]
(pass) fake node cli > entrypoint file extension picking > picks ts over js/cjs/etc [410.34ms]
(pass) fake node cli > node -e  [395.49ms]
(pass) fake node cli > -v / --version > node -v prints process.version [256.81ms]
(pass) fake node cli > -v / --version > node --version prints process.version [232.85ms]
(pass) fake node cli > -v / --version > node --version matches node -e 'console.log(process.version)' [856.08ms]
(pass) fake node cli > -v / -
... (truncated)

release with fix: all passed
$ bun scripts/build.ts --profile=release
[configured] bun-profile → bun (stripped) in 748ms (unchanged)
ninja: Entering directory `/workspace/bun/build/release'
[1/6] gen generated_host_exports.rs
generated_host_exports.rs: 94 exports (host=3, lazy=10, generic=81, rust=0); 240 extern-C blocks audited
[1/6] cargo bun_bin → libbun_rust.a (--target x86_64-unknown-linux-gnu)

  nightly-2026-07-20-x86_64-unknown-linux-gnu unchanged - rustc 1.99.0-nightly (9f36de775 2026-07-19)

�[1m�[92m   Compiling�[0m bun_core v0.0.0 (/workspace/bun/src/bun_core)
�[1m�[92m   Compiling�[0m bun_errno v0.0.0 (/workspace/bun/src/errno)
�[1m�[92m   Compiling�[0m bun_ptr v0.0.0 (/workspace/bun/src/ptr)
�[1m�[92m   Compiling�[0m bun_boringssl_sys v0.0.0 (/workspace/bun/src/boringssl_sys)
�[1m�[92m   Compiling�[0m bun_safety v0.0.0 (/workspace/bun/src/safety)
�[1m�[92m   Compiling�[0m bun_zlib_sys v0.0.0 (/workspace/bun/src/zlib_sys)
�[1m�[92m   Compiling�[0m bun_cares_sys v0.0.0 (/workspace/bun/src/cares_sys)
�[1m�[92m   Compiling�[0m bun_zstd v0.0.0 (/workspace/bun/src/zstd)
�[1m�[92m   Compiling�[0m bun_picohttp v0.0.0 (/workspace/bun/src/picohttp)
�[1m�[92m   Compiling�[0m bun_output v
... (truncated)

diff hotspot

src/runtime/cli/mod.rs       | 20 ++++++++++++++++++++
 test/cli/run/as-node.test.ts | 40 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 60 insertions(+)

gate history · 1 passed · 0 rejected · iteration 0

evidence per changed file

file                          reads  edits  tests
src/runtime/cli/mod.rs           11      6      0
test/cli/run/as-node.test.ts      1      2      0

When bun is invoked as 'node' (via the /tmp/bun-node-<rev>/node symlink that 'bun run' puts on PATH), 'node -v' and 'node --version' now print 'v<process.version>' and exit 0, matching Node.js. Previously RunAsNodeCommand used RUN_TABLE, which has no -v/--version entry: '--version' was silently dropped (empty positionals -> 'Missing script to execute'), and '-v' hit clap's short-flag chainer which hard-errors on unknown shorts. This broke engine-version preflights (node-gyp, prepare/postinstall scripts) on machines without a real node installed. The flag is only honoured before the first positional or '--', so 'node app.js --version' still passes '--version' through to the script.

robobun · 2026-07-27T17:55:10Z

^{Updated 12:04 PM PT - Jul 27th, 2026}

❌ @robobun, your commit fea90e2 has 1 failures in Build #83498 (All Failures):

test/js/bun/http/serve.test.ts - code 1 on 🍎 14 x64

🧪 To try this PR locally:

bunx bun-pr 36128

That installs a local version of the PR into your bun-36128 executable, so you can run:

bun-36128 --bun

coderabbitai · 2026-07-27T17:59:23Z

Walkthrough

Changes

The node-mode CLI handles leading -v and --version flags before initialization, prints the reported Node.js version, exits successfully, and preserves version-like arguments passed after a script. Tests cover output, stderr, exit status, and argument forwarding.

Node version flag handling

Layer / File(s)	Summary
Version flag detection `src/runtime/cli/mod.rs`	`exec_run_as_node` scans leading arguments for `-v` and `--version`, stopping at `--` or positional script arguments.
Version output and validation `src/runtime/cli/mod.rs`, `test/cli/run/as-node.test.ts`	The new helper writes the reported Node.js version and exits with status 0; tests validate output, stderr, flag equivalence, and script argument forwarding.

Suggested reviewers: cirospaciari

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title clearly summarizes the main change: adding -v/--version handling to the node argv0 shim.
Description check	✅ Passed	It explains the change and includes reproduction, cause, fix, and tests, covering the template’s purpose and verification needs.

_{Comment @coderabbitai help to get the list of available commands.}

coderabbitai

Actionable comments posted: 2

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@src/runtime/cli/mod.rs`:
- Around line 1532-1537: Update the argument scan around bun::argv() so
value-taking Node options, including --require, consume their following token
before classifying positional arguments. Preserve handling of --version and --,
continue scanning to process later flags such as --version, and add a regression
test for --require preload.js --version.

In `@test/cli/run/as-node.test.ts`:
- Around line 90-121: Extend the “node script.js --version passes the flag
through to the script” test around fakeNodeRun to cover the explicit -- option
terminator: invoke node with --, index.js, and each of --version and -v, and
assert the script receives the corresponding flag in process.argv.slice(2).

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

Push a commit to this branch (recommended)
Create a new PR with the fixes

ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: ASSERTIVE

Plan: Pro

Run ID: 3ce58083-0249-4a58-9a32-c410a21ef572

📥 Commits

Reviewing files that changed from the base of the PR and between 4eb6f99 and 102a266.

📒 Files selected for processing (2)

src/runtime/cli/mod.rs
test/cli/run/as-node.test.ts

…im comment

robobun · 2026-07-27T18:46:44Z

CI status for fea90e2: test/cli/run/as-node.test.ts (the test added here) is green on every lane.

The failures in build 83498 are all darwin-only and unrelated to this CLI argv change:

test/js/bun/http/serve.test.ts request-body backpressure (darwin 14 x64, darwin 26 aarch64): known flake, fix in flight at test(serve): fix darwin flake in the respond-without-reading-body backpressure test #36088
test/cli/run/require-cache.test.ts, test/js/web/fetch/fetch-leak.test.ts, test/regression/issue/20144/20144.test.ts (darwin 26 aarch64): tagged flaky, memory-threshold/timing tests

This diff only touches exec_run_as_node argv handling and adds a print_node_version_and_exit helper; none of the HTTP, fetch, or require-cache code paths are reachable from it. Ready for review.

robobun assigned Jarred-Sumner Jul 27, 2026

github-actions Bot added the claude label Jul 27, 2026

coderabbitai Bot reviewed Jul 27, 2026

View reviewed changes

Comment thread src/runtime/cli/mod.rs

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

test: cover 'node -- script.js --version' option-terminator passthrough

3d06ba0

github-actions Bot reviewed Jul 27, 2026

View reviewed changes

Comment thread src/runtime/cli/mod.rs Outdated

claude Bot reviewed Jul 27, 2026

View reviewed changes

Comment thread src/runtime/cli/mod.rs

Comment thread src/runtime/cli/mod.rs

cli(node shim): treat lone '-' as positional in -v/--version scan; tr…

7916043

…im comment

github-actions Bot reviewed Jul 27, 2026

View reviewed changes

Comment thread src/runtime/cli/mod.rs Outdated

cli(node shim): shrink explanatory comment to one line

fea90e2

coderabbitai Bot mentioned this pull request Aug 9, 2026

fix(cli): support 'bun node <file>' — node emulation via argv[1] #37277

Open

robobun mentioned this pull request Aug 14, 2026

node emulation: keep the first positional in process.argv for node -e / -p #38556

Open

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cli: handle -v/--version in the node argv0 shim - #36128

cli: handle -v/--version in the node argv0 shim#36128
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