fix(backend): match GitLab project topics case-insensitively

[outrunn]

Fixes #1388

Problem

GitLab connection topic filters are case-insensitive on the config side but case-sensitive on the project side. In shouldExcludeProject (packages/backend/src/gitlab.ts), the configured topics / exclude.topics are lowercased before matching, but the project's own topics (from the GitLab API) are compared in their original case. So a project whose topic is Backend does not match a config topic or glob like backend, and repositories get unexpectedly included or excluded whenever a GitLab project uses mixed-case topics.

Fix

Lowercase the project topics as well, in both the include.topics and exclude.topics branches, so matching is case-insensitive and symmetric between the configured topics and the project topics.

Before / after

Config: include.topics: ["backend"], project topic: ["Backend"]

• Before: no match -> the repository is excluded from sync.
• After: case-insensitive match -> the repository is included, as expected.

Testing

• Updated the existing test that documented the old case-sensitive behavior so it now asserts the mixed-case project topic Backend matches config backend, and added a symmetric exclude.topics test.
• yarn workspace @sourcebot/backend test --run src/gitlab.test.ts -> 13/13 passing.
• yarn workspace @sourcebot/backend exec tsc --noEmit -> clean.

Changelog

Added an entry under ## [Unreleased] -> ### Fixed.

Note on #1393

I saw #1393 takes the same approach but has unresolved conflicts and looks stale. Opening this as a clean, rebased alternative with tests in case it helps land the fix faster. Happy to close this one if the original author picks theirs back up.

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Note

Low Risk
Small, localized change to GitLab sync filtering logic with matching unit tests; no auth or data-path changes.

Overview
Fixes GitLab connection topic filtering so include.topics and exclude.topics treat project topics from the API the same way as configured patterns: both sides are lowercased before micromatch runs in shouldExcludeProject.

Mixed-case project topics (e.g. Backend) now match config like backend, so sync include/exclude rules behave as users expect instead of silently skipping or dropping repos.

Tests were updated for the include case and an exclude.topics case-insensitive test was added; the unreleased changelog notes the fix (#1388).

^{Reviewed by Cursor Bugbot for commit 9dc0eb2. Bugbot is set up for automated code reviews on this repo. Configure here.}

Summary by CodeRabbit

• Bug Fixes

  • GitLab topic filters now match project topics regardless of capitalization.
  • Included and excluded topic rules correctly handle mixed-case topics.

• Documentation

  • Updated the changelog to document the improved GitLab topic filtering behavior.

[coderabbitai]

Walkthrough

GitLab project topics are lowercased before matching against configured include and exclude topic filters. Tests cover mixed-case topics for both paths, and the changelog documents the fix.

Changes

GitLab topic filtering

Layer / File(s)	Summary
Normalize project topics for filtering packages/backend/src/gitlab.ts, packages/backend/src/gitlab.test.ts, CHANGELOG.md	Lowercases GitLab project topics before include and exclude matching, adds mixed-case coverage for both filters, and documents the fix.

Estimated code review effort: 2 (Simple) | ~10 minutes

Possibly related PRs

• sourcebot-dev/sourcebot#1028: Introduced the GitLab topic-matching logic refined by this change.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	The implementation normalizes project topics for both include and exclude matching, with tests covering mixed-case topics as required by issue #1388.
Out of Scope Changes check	✅ Passed	The changes are limited to GitLab topic matching, related tests, and the corresponding changelog entry.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the main change: case-insensitive matching for GitLab project topics in the backend.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[coderabbitai]

🧹 Nitpick comments (1)

packages/backend/src/gitlab.ts (1)

251-254: 📐 Maintainability & Code Quality | 🔵 Trivial | 💤 Low value

Simplify case-insensitive matching with micromatch options.

Both include.topics and exclude.topics paths manually create new arrays to map topics to lowercase. micromatch supports case-insensitive matching natively via the { nocase: true } option, which would allow you to skip creating intermediate lowercased arrays.

Consider refactoring both sections to use the native option:

• packages/backend/src/gitlab.ts#L251-L254: Remove .map(topic => topic.toLowerCase()) from both configTopics and projectTopics, and pass { nocase: true } to micromatch.isMatch(topic, include.topics, { nocase: true }).
• packages/backend/src/gitlab.ts#L262-L265: Remove .map(topic => topic.toLowerCase()) from both configTopics and projectTopics, and pass { nocase: true } to micromatch.isMatch(topic, exclude.topics, { nocase: true }).

🤖 Prompt for 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.

In `@packages/backend/src/gitlab.ts` around lines 251 - 254, The topic matching
logic in both include and exclude paths unnecessarily lowercases intermediate
arrays. In packages/backend/src/gitlab.ts lines 251-254, remove the lowercase
mappings and use the original topic arrays with micromatch.isMatch configured
with nocase: true; apply the same change to lines 262-265 for exclude.topics,
preserving the existing matching behavior.

🤖 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.

Nitpick comments:
In `@packages/backend/src/gitlab.ts`:
- Around line 251-254: The topic matching logic in both include and exclude
paths unnecessarily lowercases intermediate arrays. In
packages/backend/src/gitlab.ts lines 251-254, remove the lowercase mappings and
use the original topic arrays with micromatch.isMatch configured with nocase:
true; apply the same change to lines 262-265 for exclude.topics, preserving the
existing matching behavior.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: a9067891-a1c0-498d-9d1f-315d76e39e56

📥 Commits

Reviewing files that changed from the base of the PR and between a50ca10 and 20a803d.

📒 Files selected for processing (3)

• CHANGELOG.md
• packages/backend/src/gitlab.test.ts
• packages/backend/src/gitlab.ts