fix: report a provider failure when reading pull request files

[HarshMN2345]

Problem

getPullRequestFiles() assumed every response body was a list of file records:

$files = $response['body'] ?? [];
$allFiles = array_merge($allFiles, $files);

GitHub checked no status at all, so an authorization, rate-limit or gateway response reached array_merge() and raised a TypeError — Appwrite reported an unexpected 500 instead of a controlled failure. Gitea and Forgejo checked the status but not the body, and raised the identical TypeError on a non-JSON body (an HTML error page from a proxy decodes to a string).

Reading an error payload as a file list is the quieter half, and it does not crash:

Adapter	Status checked	{"message": "Bad credentials"} at 200	HTML error page at 200
GitHub	no	returned the payload as the file list	TypeError
Gitea / Forgejo	yes	returned the payload as the file list	TypeError
GitLab	yes	returned [{"filename": ""}]	returned []
Bitbucket	yes	[], correctly — its pages are objects	returned []

Both consumers read filename / previous_filename off the result to decide which deployments a push affects, so a failed fetch that returns an empty list looks like a pull request that changed nothing, and the deployments are silently skipped. That failure mode reaches no error tracker at all.

Fix

Check the status before the body on GitHub, and require a list of file records everywhere before merging one. Pagination is unchanged in every adapter.

Only GitHub is released today, which is why it is the only one reporting this — not the only one affected.

Test plan

Base now drives these paths from canned responses, since a live forge cannot be made to page or fail on demand. Each adapter describes its own page shape through pullRequestFilesPage(); Gogs opts out through the $supportsPullRequestLookup flag it already sets, and Forgejo inherits Gitea's coverage.

Four tests per adapter — pagination across two pages, 401/403/404/500, a failure on a later page, and malformed bodies. Reverting src/ alone fails 7 of them, across all five supported adapters, including both array_merge() TypeErrors. The pagination tests pass before and after, which is what shows paging is untouched.

composer lint and composer check are clean.

Note for review: these run through setupAdapter(), so they need the usual credentials or compose stack. I could not bring a forge up locally (Docker daemon unresponsive) and verified the harness with throwaway subclasses that stub setupAdapter(). CI is the first run through the real path.

🤖 Generated with Claude Code

[greptile-apps]

Greptile Summary

The PR makes pull-request file retrieval fail explicitly on provider errors or malformed response bodies instead of returning misleading empty results or triggering type errors.

• Adds HTTP-status validation to GitHub pull-request file pagination.
• Validates provider-specific page shapes across GitHub, GitLab, Gitea/Forgejo, and Bitbucket.
• Adds shared replay-driven coverage for pagination, provider failures, later-page failures, and malformed bodies.

Confidence Score: 5/5

The PR appears safe to merge because no blocking failure remains.

No blocking failure remains.

Important Files Changed

Filename	Overview
src/VCS/Adapter/Git/GitHub.php	Adds status and list-shape validation before merging paginated GitHub pull-request files.
src/VCS/Adapter/Git/GitLab.php	Rejects malformed merge-request diff bodies while preserving empty-list pagination termination.
src/VCS/Adapter/Git/Gitea.php	Requires pull-request file pages to be lists; Forgejo inherits the same validation.
src/VCS/Adapter/Git/Bitbucket.php	Converts malformed diffstat page objects and values collections from silent termination into explicit failures.
tests/VCS/Base.php	Adds shared mocked-response tests for pagination and provider failure handling across supported adapters.
tests/VCS/Adapter/GitLabTest.php	Defines GitLab’s page shape and prepends the merge-request readiness response required by its call sequence.
tests/VCS/Adapter/BitbucketTest.php	Defines Bitbucket’s object-based diffstat pagination fixture and applicable malformed-body case.
tests/VCS/Adapter/GitHubTest.php	Allows replay mocks to bypass GitHub App token initialization.

_{Reviews (2): Last reviewed commit: "style: keep the pull request files comme..." | Re-trigger Greptile}