fix(ci-insights): Use base branch presence as PR indicator for mode selection

[remyduthu]

The mode selection between 'new' and 'unhealthy' was using branch_name
presence, which derived from BASE with HEAD fallback. Since HEAD is
almost always available (via GITHUB_REF_NAME), scheduled/push runs
incorrectly selected 'new' mode.

Fixes: MRGFY-6820

Co-Authored-By: Claude Opus 4.6 (1M context) noreply@anthropic.com

[mergify]

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[Copilot]

Pull request overview

Fixes CI Insights “mode” selection so flaky detection uses new mode only in PR contexts and unhealthy mode for push/scheduled runs, avoiding incorrect new mode selection when only HEAD refs are available.

Changes:

• Update MergifyCIInsights to select flaky-detector mode based on presence of a PR base ref attribute.
• Refactor _load_flaky_detector() to accept an explicit mode argument.
• Adjust CI Insights tests to model PR vs push/scheduled environments using GITHUB_BASE_REF and GITHUB_REF_NAME.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
pytest_mergify/ci_insights.py	Passes an explicit flaky-detector mode chosen from resource attributes rather than relying on branch_name presence.
tests/test_ci_insights.py	Updates test env setup to simulate PR vs non-PR contexts via GitHub Actions ref env vars.

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[JulianMaurin]

For push/schedule runs where GITHUB_BASE_REF="" is present in the environment, get_attributes will include VCS_REF_BASE_NAME="" in the resource. The branch_name derivation:
branch_name = resource.attributes.get(VCS_REF_BASE_NAME, resource.attributes.get(VCS_REF_HEAD_NAME))
would return "" instead of falling through to HEAD. This makes self.branch_name = "" (falsy), which means quarantine won't load for push runs even when a HEAD ref is available. This is out of scope for this PR
but worth a follow-up if quarantine is expected to work on push/schedule.

[remyduthu]

For push/schedule runs where GITHUB_BASE_REF="" is present in the environment, get_attributes will include VCS_REF_BASE_NAME="" in the resource. The branch_name derivation: branch_name = resource.attributes.get(VCS_REF_BASE_NAME, resource.attributes.get(VCS_REF_HEAD_NAME)) would return "" instead of falling through to HEAD. This makes self.branch_name = "" (falsy), which means quarantine won't load for push runs even when a HEAD ref is available. This is out of scope for this PR but worth a follow-up if quarantine is expected to work on push/schedule.

Nice catch! I'll push another fix.

[remyduthu]

This pull request is part of a stack:

1. fix(ci-insights): Use base branch presence as PR indicator for mode selection (#392) 👈
2. fix(ci-insights): Handle empty base ref in branch name derivation (#393)

[mergify]

Merge Queue Status

• ✅ Entered queue — 2026-04-03 11:22 UTC · Rule: default
• ✅ Checks skipped · PR is already up-to-date
• ✅ Merged — 2026-04-03 11:23 UTC · at 1c0965b4211b3ca2341606b9fb0ed7b6d1e12fe7

This pull request spent 24 seconds in the queue, including 1 second running CI.

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