fix(completions): undefined variable leading to bash completion errors

[carschandler]

What does this PR do?

Fixes #24847

Not sure what the original intent of this undefined variable was but I'd rather have a working version than try to fully fix that functionality

How did you verify your code works?

Edited the currently installed completions script from my bun install with identical changes

[coderabbitai]

Walkthrough

Removed an alternative condition in the bash completion script's _read_scripts_in_package_json function that previously allowed triggering completion via re_comp_word_script pattern matching. Completion now only proceeds when previous-completion matches re_prev_script and COMP_WORDS[2] is non-empty, tightening the trigger logic.

Changes

Cohort / File(s)	Summary
Bash Completion Logic completions/bun.bash	Removed secondary guard condition in _read_scripts_in_package_json that depended on re_comp_word_script matching. Narrows completion trigger to only proceed when COMPREPLY matches re_prev_script and COMP_WORDS[2] is non-empty.

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title 'fix(completions): undefined variable leading to bash completion errors' clearly and specifically describes the main change - fixing an undefined variable that causes bash completion errors.
Description check	✅ Passed	The description includes both required sections from the template: 'What does this PR do?' with a link to the issue and explanation, and 'How did you verify your code works?' with verification details.
Linked Issues check	✅ Passed	The code changes address the core requirement from issue #24847: removing the undefined variable in the bash completions script that caused the 'invalid regular expression' error, restoring functional tab completion.
Out of Scope Changes check	✅ Passed	All changes are directly scoped to fixing the bash completion error in completions/bun.bash by removing the problematic secondary condition, with no unrelated modifications.

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[coderabbitai]

Actionable comments posted: 0

Caution

Some comments are outside the diff and can’t be posted inline due to platform limitations.

⚠️ Outside diff range comments (1)

completions/bun.bash (1)

1-1: 🧹 Nitpick | 🔵 Trivial

Pre-existing: Shebang is malformed.

The shebang line is missing ! and should be #!/usr/bin/env bash. While completion scripts are typically sourced rather than executed directly (so this may not cause immediate issues), it's still incorrect.

Proposed fix

-#/usr/bin/env bash
+#!/usr/bin/env bash

[claude]

Code Review

No issues found. Checked for bugs and CLAUDE.md compliance.

[robobun]

Keeping this one as the fix for #24847 (triaging the open completion PRs). Notes for whoever merges:

• It still merges cleanly: a8d0692 (Hardening round 11: input validation, bounds checks, lifetimes #33072) rewrote the body of this block but not the two lines removed here. It also merges cleanly alongside completions: complete files for bun <path> and skip runtime flags before dispatch #36629, feat(completions): add --watch and --update-snapshots to bun test completions #27908, Add --frozen-lockfile to completions for bun install in fish. #29364, fix(completions): correct zsh quote parity for -i flag spec #31665 and fix(completions): pipe history array into grep instead of executing it #34062.
• Dropping the dead arm does more than silence the macOS error. Under GNU regex an empty pattern always matches, so on Linux this block ran unconditionally and stripped the scripts _read_scripts_in_package_json had just added. With current main, in a project whose package.json has build/lint/dev:web scripts, bun run <TAB> offers only the six run flags and bun run l<TAB> offers nothing; with this patch they offer the scripts. (Before a8d0692 the prefix case happened to work because the old sed-based filter only removed the full list; the exact-match filter introduced there removes them in every case.)
• The one observable change besides that: bun somefile.js <TAB> used to offer the 42 legacy global flags because replaced_script was always set; it now offers nothing from this arm. completions: complete files for bun <path> and skip runtime flags before dispatch #36629 replaces that arm with flags plus file completion, so that case is covered there.
• Closed fix(completions): remove dead branch referencing undefined variable in bash completion #28744 (same two-line change, now conflicting with main) and completions: fix 4 correctness bugs in zsh/bash/fish scripts #36515 (its bash change made the block unconditional instead, which keeps scripts from ever being offered) in favour of this.
• Fix bun bash completion regex error #21778 is an older alternative for the same bug that populates re_comp_word_script instead of dropping the arm (it also implements the original "hide the other scripts once one was typed" intent and fixes a [A-Za_z] typo). Whichever of the two lands makes the other unnecessary.