From e0894cc107d72ffe16c312fc8325f77cce1fa751 Mon Sep 17 00:00:00 2001
From: Diego Rodrigues de Sa e Souza
 <8016841+diegosouzapw@users.noreply.github.com>
Date: Fri, 17 Jul 2026 01:01:38 -0300
Subject: [PATCH] fix(ci): fetch full base history in pr-test-policy (shallow
 graft broke merge-base) (#7501)
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With --depth=1 the base ref is grafted, so 'git diff base...HEAD' resolves a
wrong merge-base for PR branches that recently merged the release branch. The
three-dot diff then attributes ALREADY-MERGED sibling PRs' changes to the PR
under test, producing false high-signal reds (deleted test files / weakened
asserts that exist in no ref reachable from the PR).

Observed live on #7329: the job blamed it for tests/unit/ui/provider-plan-config.test.tsx
(deleted by an unrelated merged PR) and for #7106's antigravity files. Local
reproduction with full history returns PASS for the same head.

The job's checkout is already fetch-depth: 0, so the full base fetch only
updates the ref — negligible cost.
---
 .github/workflows/ci.yml                                  | 2 +-
 changelog.d/maintenance/ci-pr-test-policy-shallow-base.md | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)
 create mode 100644 changelog.d/maintenance/ci-pr-test-policy-shallow-base.md

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 917ca860aa..d97161e470 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -519,7 +519,7 @@ jobs:
         with:
           node-version: ${{ env.CI_NODE_VERSION }}
       - name: Fetch base branch
-        run: git fetch --no-tags origin "${GITHUB_BASE_REF}" --depth=1
+        run: git fetch --no-tags origin "${GITHUB_BASE_REF}"
       - name: Validate source changes include tests
         run: node scripts/check/check-pr-test-policy.mjs --summary-file .artifacts/pr-test-policy.md
       # Anti test-masking: flag net assert removal / new assert.ok(true) in changed tests.
diff --git a/changelog.d/maintenance/ci-pr-test-policy-shallow-base.md b/changelog.d/maintenance/ci-pr-test-policy-shallow-base.md
new file mode 100644
index 0000000000..340b60a5ce
--- /dev/null
+++ b/changelog.d/maintenance/ci-pr-test-policy-shallow-base.md
@@ -0,0 +1 @@
+- CI: `pr-test-policy` fetches the base branch with full history instead of `--depth=1` — the shallow graft made `merge-base` resolve wrong for PR branches that recently merged the release, so the three-dot diff blamed the PR for OTHER merged PRs' changes (false "deleted test"/"weakened asserts" reds; observed on #7329 being blamed for #7106's files).