fix: use snip check/run subcommands, fix pipe handling, fix multi-word args for snip check by lenucksi · Pull Request #14 · VincentHardouin/opencode-snip

lenucksi · 2026-05-18T11:29:54Z

Summary

Replaces the hardcoded UNPROXYABLE_COMMANDS list with a runtime snip check call, fixes all pipe segments being checked (not just the first), and fixes multi-word command detection for snip check.

Fixes #6, #7.
Closes #13 (superseded by this PR).

Changes

1. Dynamic command filtering via `snip check`/`snip run` (snip >= 0.16.0)

Removes hardcoded UNPROXYABLE_COMMANDS set
Uses snip check -- <cmd> at runtime to determine filter status
Uses snip run -- <cmd> for wrapping (safer than plain snip <cmd>)
Only commands with snip filters are wrapped (git, go, ls, jq, npm, ...)
Builtins without snip filters are never wrapped (cd, export, source, ...)
Falls back gracefully if snip >= 0.16.0 is not installed

2. Fixed: multi-word args for `snip check`

snip check -- "git log -10" returns no filter (one string arg), but snip check -- git log -10 correctly returns filter: git-log. The first two words of the command are now passed as separate {raw: w} arguments to snip check.

3. Fixed: all pipe segments are checked (not just the first)

Previously only the first command before | was evaluated. Now:

Quote-aware pipe splitting (pipes inside '...'/"..." are ignored)
Each pipe segment is individually resolved via snip check + processSegment
Compound operators (&&, ||, ;, &) work within each pipe segment
|| is treated as a compound operator, not a pipe

Command	Result
`git log -10	head -5`
`cat file.json	jq '.a
`cd /tmp && snip run -- git log	head`
`cmd1	cmd2` (no filters)

4. Maintenance

Replaced console.warn with client.app.log (prevents UI mangling)
try/catch wrapper for resilience
Removed findFirstPipe — now inline quote-aware pipe processing
Added version check for snip >= 0.16.0
Prevent double snip prefix in compound commands
Added docs/PIPE-HANDLING.md documenting pipe resolution behavior

Acknowledgements

This PR builds on the foundational work by @JoaoCostaIFG in PR #13, which introduced
the snip check/snip run subcommand approach and replaced console.warn with
client.log. Thank you for laying that groundwork!

… list Replaces the static UNPROXYABLE_COMMANDS set with runtime snip check calls to determine whether a command should be wrapped by snip. Only commands with existing snip filters (snip check exit 0) get prefixed with snip run --. Changes: - Introduce DI pattern createToolExecuteBefore(shouldWrap) for testability - Replace hardcoded unproxyable commands with snip check invocation - Use snip run -- prefix instead of bare snip - Deduplicate findFirstPipe call - Replace console.warn with client.log - Add try/catch guard for resilience Fixes VincentHardouin#6, VincentHardouin#7

snip check expected each word as a separate argument to match multi-word filters (e.g. "git log" matches filter git-log). Previously the whole cmd string was passed as one raw arg.

Previously only the first command before the first | was checked. Now the command is split by all pipes (outside quotes, ignoring ||) and each segment is individually processed (with compound operator handling within each segment). Non-wrapped segments preserve output, wrapped segments get snip run --. Segments joined with " | ".

VincentHardouin · 2026-05-18T12:19:54Z

@@ -0,0 +1,44 @@
+# Pipe Handling


This file is unnecessary, and the behavior should be documented through testing. Please remove the commit (d27373f) that adds it 🙏

Done — commit d27373f reverted, docs/PIPE-HANDLING.md removed. The pipe-splitting behavior is now covered by the updated tests (pipe expressions with quotes, 2>&1 with pipe, etc.).

Can you push changes please ?

Done — pushed commit 882fa4b with all the changes. Includes the {raw: w} fix from Greptile's P2 review too.

The commit isn't included in this PR. Could you fix that?

Sorry, pushed to the wrong branch. Should be visible now.

VincentHardouin · 2026-05-18T12:29:30Z

+async function defaultShouldWrap(cmd: string): Promise<boolean> {
+  const baseCmd = cmd.split(/\s+/)[0]
+  return WRAPPED_COMMANDS.has(cmd) || WRAPPED_COMMANDS.has(baseCmd)
+}


I think in the tests, we could call it mockedWrap and just return true. This would allow us to remove the WRAPPED_COMMANDS variable, which lists all the commands in the tests and seems unnecessary to me.

Done — WRAPPED_COMMANDS and defaultShouldWrap replaced with a simple mockedWrap = async () => true. The tests now focus on verifying the splitting/prefixing logic rather than simulating filter lists. All test expectations updated accordingly (every segment gets wrapped in tests).

VincentHardouin · 2026-05-18T12:35:12Z

+    it("should skip cd but wrap chained command via shouldWrap", async () => {
+      const shouldSkip = async (cmd: string) => !cmd.startsWith("cd ")
      mockOutput.args.command = "cd /tmp && ls"
-      await toolExecuteBefore(mockInput, mockOutput)
-      expect(mockOutput.args.command).toBe("cd /tmp && snip ls")
+      await createToolExecuteBefore(shouldSkip)(mockInput, mockOutput)
+      expect(mockOutput.args.command).toBe("cd /tmp && snip run -- ls")
    })


I feel like these tests aren't useful anymore. snip check now checks to make sure it can't run cd, so what we want to verify is that every subcommand has been successfully passed to snip check. What do you think about updating the test to reflect that?

Done — the old "commands that should not be wrapped" section is replaced with a "subcommand passthrough" describe block. It uses a spy that captures which subcommands are passed to shouldWrap, verifying that each &&/|/; segment is correctly isolated and forwarded. This is more useful — tests the parser, not the filter logic.

VincentHardouin · 2026-05-18T12:43:53Z

Also, as I mentioned in PR #13 (comment), we need to warn users who don't have a version of Snip that includes the snip check and snip run commands, so that the plugin doesn't run.

Add snip-prefix guard in snipCommand() to avoid double-wrapping when a segment in a compound command (connected via && or |) already contains snip run --. The existing top-level guard in createToolExecuteBefore only covered the full command, not individual segments after splitting. Add 4 test cases for already-prefixed segments in compound commands.

lenucksi · 2026-05-18T13:55:40Z

@VincentHardouin re: snip version check — done. Added hasSnipSubcommands($) right after the which snip check in SnipPlugin. If snip check -- ls fails, the plugin logs a warning and returns {}. Also exported the function with $ mock tests for coverage.

greptile-apps · 2026-05-18T18:46:54Z

Greptile Summary

This PR replaces the static UNPROXYABLE_COMMANDS allowlist with runtime snip check / snip run -- calls (requiring snip ≥ 0.16.0), fixes pipe handling so every segment is individually evaluated, and adds a quote-aware pipe splitter that correctly ignores | inside '...' and \"...\".

createToolExecuteBefore is now a factory that accepts a shouldWrap callback, enabling unit tests to inject a mock without spawning real processes; the shouldWrap implementation in SnipPlugin calls snip check -- <word0> [word1] and wraps on exit code 0.
A hasSnipSubcommands version gate runs once at startup and disables the plugin if snip check is not available, with proper .nothrow() so exit code 1 (no filter found) is treated as "subcommand present" rather than "binary missing".
An experimental.chat.system.transform hook injects a system prompt telling the model not to add snip run -- manually.

Confidence Score: 4/5

Safe to merge for the common case; quote-state tracking has a known gap for $() subshell substitutions and backslash-escaped quotes that could produce broken command strings on those inputs.

The core logic is well-tested and the three issues called out in previous review rounds are addressed. The remaining gap is the pipe-splitter's unawareness of $() subshell syntax and " escapes: a command like echo $(git log | head -5) | xargs would be split at the inner pipe, producing malformed segments. This affects a real but minority of real-world commands.

src/index.ts — the quote-aware pipe-splitting loop (lines 45–66) does not track $() nesting or backslash escapes.

Important Files Changed

Filename	Overview
src/index.ts	Core rewrite replacing static UNPROXYABLE_COMMANDS with dynamic snip check calls, adding quote-aware full-pipeline splitting, and wrapping commands with snip run --. Quote-state tracker has known gaps for $() and " escapes.
src/index.test.ts	Comprehensive test update: replaces static WRAPPED_COMMANDS mock with shouldWrap spy, adds pipe-segment passthrough checks, error-guard tests, and hasSnipSubcommands unit tests. Coverage is thorough for the supported syntax.
README.md	Adds development quickstart (npm ci / typecheck / test) to the Development section.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A[tool.execute.before hook] --> B{tool === bash?}
    B -- No --> Z[return unchanged]
    B -- Yes --> C{starts with snip?}
    C -- Yes --> Z
    C -- No --> D[Quote-aware pipe split]
    D --> E{Pipe segments found?}
    E -- No --> F[processSegment]
    E -- Yes --> G[processSegment per segment]
    F --> H[snipCommand per operator-split part]
    G --> H
    H --> I{bareCmd starts with snip?}
    I -- Yes --> J[return unchanged]
    I -- No --> K[shouldWrap: snip check w0 w1]
    K -- exit 0 --> L[prefix with snip run --]
    K -- non-zero or throw --> M[return unchanged]
    L --> N[reassemble segments]
    J --> N
    M --> N
    N --> O[output.args.command = result]

_{Reviews (6): Last reviewed commit: "feat: inject usage instructions into sys..." | Re-trigger Greptile}

greptile-apps · 2026-05-18T18:46:57Z

  it("should handle command with |", async () => {
    mockOutput.args.command = "git log | head"
-    await toolExecuteBefore(mockInput, mockOutput)
-    expect(mockOutput.args.command).toBe("snip git log | head")
+    await createToolExecuteBefore(defaultShouldWrap)(mockInput, mockOutput)
+    expect(mockOutput.args.command).toBe("snip run -- git log | head")
  })


Stale pipe test expectations cause multiple failures

With the new multi-segment pipe processing, every pipe segment is independently evaluated by shouldWrap. Because WRAPPED_COMMANDS includes "head", "grep", "jq", "cat", and "echo" (all matched by baseCmd), every segment of a pipeline gets wrapped. However, the expected values throughout this section were copied from the old single-segment tests and still show only the first segment wrapped.

Concrete failures:

git log | head → actual snip run -- git log | snip run -- head, expected snip run -- git log | head

cat file.json | jq '.content | .text' → actual snip run -- cat file.json | snip run -- jq '.content | .text', expected snip run -- cat file.json | jq '.content | .text'

find / -name "*.log" 2>&1 | grep error → both find and grep get wrapped, expected only find

echo "hello | world" | cat → both echo and cat wrapped, expected only echo

The WRAPPED_COMMANDS set also contains full-pipeline strings like "cat file.json | jq '.content | .text'" that can never match after pipe splitting — those entries are dead weight. Either remove head, grep, cat, jq, echo from WRAPPED_COMMANDS so the mock simulates a realistic snip check (only git, go, etc. have filters), or update the expected values to reflect both segments being wrapped.

Resolved — WRAPPED_COMMANDS/defaultShouldWrap removed in favor of mockedWrap = async () => true. All pipe expectations updated so every segment is wrapped. Both git log | head and cat file.json | jq ... expectations now correctly show both segments prefixed.

greptile-apps · 2026-05-18T18:46:58Z

+      const words = cmd.split(/\s+/)
+      const result = await $`snip check -- ${words.map(w => ({raw: w}))}`.nothrow().quiet()


Shell metacharacters in command words bypass escaping with {raw: w}

cmd.split(/\s+/) can produce words containing shell-special characters — most notably > and & from redirections like 2>&1. Passing these via {raw: w} means they are interpreted by the shell rather than forwarded as literal arguments to snip check. For shouldWrap("cmd1 2>&1"), the shell ends up running snip check -- cmd1 2>&1 (with stderr redirected) instead of snip check -- cmd1 '2>&1'.

While .quiet().nothrow() means only exitCode is consumed (so the redirect usually doesn't change the result), any word containing ; would split the command at the shell level and could execute unintended sub-commands. Dropping {raw: ...} and passing words directly lets bun's $ template tag quote each element correctly.

Suggested change

const words = cmd.split(/\s+/)

const result = await $`snip check -- ${words.map(w => ({raw: w}))}`.nothrow().quiet()

const words = cmd.split(/\s+/)

const result = await $`snip check -- ${words}`.nothrow().quiet()

Fixed — dropped {raw: w}, now passes words directly so bun's $ template tag handles quoting. Words like 2>&1 or ; are now forwarded as literal arguments to snip check instead of being interpreted by the shell.

… fix shell escaping - Remove docs/PIPE-HANDLING.md (owner feedback: test > docs) - Replace WRAPPED_COMMANDS/defaultShouldWrap with mockedWrap - Replace cd/skip tests with subcommand-passthrough spy tests - Add hasSnipSubcommands() to warn when snip < 0.16.0 - Drop {raw: w} to prevent shell metacharacter injection in snip check

greptile-apps · 2026-05-18T20:20:47Z

+export async function hasSnipSubcommands($: any): Promise<boolean> {
+  try {
+    await $`snip check -- ls`.quiet()
+    return true
+  } catch {
+    return false
+  }
 }


hasSnipSubcommands conflates "subcommand not found" with "ls has no filter". Without .nothrow(), bun's $ throws on any non-zero exit — including exit code 1 from snip check -- ls when ls simply has no filter configured. The catch block then returns false, disabling the plugin entirely with the misleading message "snip >= 0.16.0 required". Any user whose snip config doesn't include an ls filter (but does have git, npm, docker, etc.) will silently lose all wrapping.

Using .nothrow() and treating any completed run (exit 0 or non-zero) as proof that the check subcommand exists fixes this: a real "command not found" / missing-subcommand failure will still throw and return false.

Suggested change

export async function hasSnipSubcommands($: any): Promise<boolean> {

try {

await $`snip check -- ls`.quiet()

return true

} catch {

return false

}

}

export async function hasSnipSubcommands($: any): Promise<boolean> {

try {

await $`snip check -- ls`.nothrow().quiet()

return true

} catch {

return false

}

}

Good catch — fixed. Added .nothrow() so exit code 1 (ls has no filter) is treated as "subcommand exists". Only a real throw (command not found) triggers the warning and plugin disable. Also added a test for the exit-code-1 case.

…exit-1

VincentHardouin · 2026-05-19T07:06:34Z

@lenucksi the CI fails can you correct this before I continue the review please?

…ADME

lenucksi · 2026-05-19T15:51:15Z

@lenucksi the CI fails can you correct this before I continue the review please?

Should be addressed now and pass CI green. Does so at least locally.

…rray-in-template issues)

lenucksi · 2026-05-20T10:45:34Z

Re: Greptile P2 — {raw: w} and shell metacharacters The current code wraps only the first two words of the command as individual {raw: w0} / {raw: w1} template arguments: P2 correctly notes that {raw: ...} bypasses shell escaping. However, this is safe in practice because words[0] and words[1] are always the command and its subcommand (git, log, npm, install, sudo, go, ...) - never redirects or operators like 2>&1 or ;, which only appear at position >= 2. That said, the theoretical concern could be eliminated by dropping {raw} entirely and using plain ${words[0]} / ${words[1]} - bun's $ tag would quote them automatically. I avoided this to stay consistent with the array-to-individual-args fix in 952faf4, but am happy to switch if preferred.

…hat.system.transform The plugin now tells the AI via the system prompt to not manually prefix commands with `snip run --` — the plugin handles that automatically.

lenucksi added 4 commits May 18, 2026 12:41

fix: split cmd into separate args for snip check

2aa8086

snip check expected each word as a separate argument to match multi-word filters (e.g. "git log" matches filter git-log). Previously the whole cmd string was passed as one raw arg.

docs: add pipe handling documentation

d27373f

This was referenced May 18, 2026

Use the new snip run and check subcommands #13

Open

Can snip only be used for adapted commands? Otherwise, exceptions often occur in other commands. #6

Open

Using this changes all granular permissions #7

Open

VincentHardouin reviewed May 18, 2026

View reviewed changes

greptile-apps Bot reviewed May 18, 2026

View reviewed changes

fix: add .nothrow() to hasSnipSubcommands to avoid false-positive on …

dad0801

…exit-1

fix: use client.app.log for type-safe logging, add dev commands to RE…

a421df4

…ADME

fix: pass first two words as separate raw args to snip check (avoid a…

952faf4

…rray-in-template issues)

feat: inject usage instructions into system prompt via experimental.c…

bdb4410

…hat.system.transform The plugin now tells the AI via the system prompt to not manually prefix commands with `snip run --` — the plugin handles that automatically.

		const words = cmd.split(/\s+/)
		const result = await $`snip check -- ${words.map(w => ({raw: w}))}`.nothrow().quiet()

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Summary

Changes

1. Dynamic command filtering via snip check/snip run (snip >= 0.16.0)

2. Fixed: multi-word args for snip check

3. Fixed: all pipe segments are checked (not just the first)

4. Maintenance

Acknowledgements

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VincentHardouin commented May 18, 2026

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lenucksi commented May 18, 2026

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greptile-apps Bot commented May 18, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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Greptile Summary

Confidence Score: 4/5

Important Files Changed

Flowchart

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VincentHardouin commented May 19, 2026

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lenucksi commented May 18, 2026 •

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1. Dynamic command filtering via `snip check`/`snip run` (snip >= 0.16.0)

2. Fixed: multi-word args for `snip check`

greptile-apps Bot commented May 18, 2026 •

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