fix(psql): strip trailing semicolon before appending auto-LIMIT

[NicolaasGrobler]

Summary

• The psql console's auto-LIMIT helper appended LIMIT 1000 verbatim, so SELECT 1; produced SELECT 1; LIMIT 1000 — two statements, the second invalid (syntax error at or near "LIMIT").
• Extracted the inline helper from MainContent.tsx into a pure src/utils/applyQueryLimit.ts so it can be unit-tested without jsdom, then strip any trailing ; + whitespace before appending.

Testing

• New src/utils/applyQueryLimit.test.ts covering the regression (SELECT 1;, SELECT 1, SELECT 1; , SELECT 1 WHERE x = 1; all → ... LIMIT 1000 with no trailing ;) plus skip-cases (non-SELECT, already-has-LIMIT, CTE, UNION).
• npx tsc --noEmit clean.

Closes #38

Summary by CodeRabbit

• New Features

  • Automatically applies safe row limits to eligible SQL queries, handling trailing semicolons, end-of-query comments, existing limits, and complex query forms to avoid unintended modifications.

• Tests

  • Added thorough regression tests covering trailing-semicolon/comment trimming, preservation of inline comments, non-SELECT behavior, existing limits, and complex-query detection.

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Project	Deployment	Actions	Updated (UTC)
queryden	Ready	Preview, Comment	May 15, 2026 9:08am

[coderabbitai]

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📝 Walkthrough

Walkthrough

Extracts an inline SQL LIMIT helper into src/utils/applyQueryLimit.ts, replaces the inline helper in MainContent.tsx with the import, and adds Vitest tests validating trailing-semicolon and other edge-case behaviors.

Changes

Query Limit Utility Extraction and Enhancement

Layer / File(s)	Summary
applyQueryLimit implementation src/utils/applyQueryLimit.ts	New exported applyQueryLimit(query, maxRows) detects SELECT-like queries (skips non-SELECT, SHOW/EXPLAIN/RETURNING), avoids double-appending LIMIT, skips complex queries (CTEs, parenthesized SELECTs, UNION/INTERSECT/EXCEPT), strips trailing semicolons and end-of-query comments, and appends LIMIT <maxRows> to eligible queries.
applyQueryLimit Vitest suite src/utils/applyQueryLimit.test.ts	Adds tests confirming trailing semicolon (and semicolon+whitespace) are removed before appending LIMIT, trailing line/block comments after a semicolon are stripped, inline comments are preserved, non-SELECT queries are unchanged, existing LIMIT is not duplicated, and CTE/UNION queries are unmodified.
MainContent component integration src/components/layout/MainContent.tsx	Replaces the inline applyQueryLimit helper with an import from ../../utils/applyQueryLimit and adjusts executeQuery to rely on the shared utility.

🎯 3 (Moderate) | ⏱️ ~20 minutes

🐰 I found a stray semicolon last night,
Snipped it off tidy, then set LIMIT right.
Tests hop around to ensure no surprise,
Queries now run clean beneath open skies. 🥕

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 50.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately summarizes the main change: fixing the psql auto-LIMIT feature by stripping trailing semicolons before appending LIMIT, which directly addresses issue #38.
Linked Issues check	✅ Passed	The PR fully addresses issue #38 objectives: strips trailing semicolons before appending LIMIT, includes comprehensive Vitest tests covering the regression cases and skip conditions, and type-checking passes.
Out of Scope Changes check	✅ Passed	All changes are in-scope: extracting the inline helper to a testable utility, implementing the fix for trailing semicolons, and adding comprehensive test coverage for issue #38.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/38-psql-auto-limit-trailing-semicolon

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[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/utils/applyQueryLimit.test.ts`:
- Around line 10-28: The test suite is missing a regression test for queries
that end with a SQL line comment after a semicolon (e.g. "SELECT 1; --
comment"), which currently allows the LIMIT to be commented out; add a new spec
in applyQueryLimit.test.ts under the "trailing semicolon stripping" describe
block that calls applyQueryLimit with an input like "SELECT 1; -- comment" (and
one with trailing whitespace after the comment) and expects "SELECT 1 LIMIT
1000" to ensure applyQueryLimit correctly strips the semicolon and comment
before appending the LIMIT.

In `@src/utils/applyQueryLimit.ts`:
- Line 49: The current trimmed = query.trim().replace(/;\s*$/, "") fails when
the query ends with a trailing SQL comment; update this logic to first strip
trailing comments (both single-line -- and block /* */) from the trimmed query
(reuse the same comment-stripping approach used earlier in the function for
query detection), then remove a trailing semicolon from that comment-stripped
string, and finally use that cleaned string for appending the LIMIT (or reattach
preserved comments after adding LIMIT if desired). Target the trimmed variable
and the semicolon-removal step in the applyQueryLimit function so trailing
comments cannot cause the LIMIT to be commented out.

🪄 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

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Configuration used: defaults

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Run ID: 8e0f2399-f989-4e7f-a25c-4b82520d92d3

📥 Commits

Reviewing files that changed from the base of the PR and between bf43c8f and c087d18.

📒 Files selected for processing (3)

• src/components/layout/MainContent.tsx
• src/utils/applyQueryLimit.test.ts
• src/utils/applyQueryLimit.ts