Check Azure Devops Merge Commit statuses

[rarkins]

Tell us more.

From a Mend.io customer who's using Renovate:

I believe it's how Renovate checks the statuses and how Azure DevOps PR work when you have build policy set with build expiration.

In short, Azure DevOps in such configuration creates new temporary commit for the purpose of building PR's commit. Then that temporary commit is tagged with the build status while the original commit (latest commit on PR's branch) is left un-tagged.

From Azure DevOps API perspective:
GET https://dev.azure.com/{{organization}}/_apis/git/pullrequests/{{pullRequestId}}?api-version=4.1
returns object that contains:

`lastMergeSourceCommit.commitId` - it is the latest commit on PR's branch

`lastMergeCommit.commitId` - it is that temporary commit created for PR's build

If you then use the
GET https://dev.azure.com/{{organization}}/{{project}}/_apis/git/repositories/{{repositoryId}}/commits/{{commitId}}/statuses?latestOnly=true&api-version=4.1
with above commit IDs you can tell that only temporary commit contains the build status, while the latest commit on PR's branch has no build status at all.

First point of clarification: Renovate uses the AZDO SDK instead of API directly.

Renovate's getBranchStatus() implementation for AZDO is here:

renovate/lib/modules/platform/azure/index.ts

Lines 405 to 446 in a581f7b

	export async function getBranchStatus(
	branchName: string,
	internalChecksAsSuccess: boolean,
	): Promise<BranchStatus> {
	logger.debug(`getBranchStatus(${branchName})`);
	const statuses = await getStatusCheck(branchName);
	logger.debug({ branch: branchName, statuses }, 'branch status check result');
	if (!statuses.length) {
	logger.debug('empty branch status check result = returning "pending"');
	return 'yellow';
	}
	const noOfFailures = statuses.filter(
	(status) =>
	status.state === GitStatusState.Error ||
	status.state === GitStatusState.Failed,
	).length;
	if (noOfFailures) {
	return 'red';
	}
	const noOfPending = statuses.filter(
	(status) =>
	status.state === GitStatusState.NotSet ||
	status.state === GitStatusState.Pending,
	).length;
	if (noOfPending) {
	return 'yellow';
	}
	if (
	!internalChecksAsSuccess &&
	statuses.every(
	(status) =>
	status.state === GitStatusState.Succeeded &&
	status.context?.genre === 'renovate',
	)
	) {
	logger.debug(
	'Successful checks are all internal renovate/ checks, so returning "pending" branch status',
	);
	return 'yellow';
	}
	return 'green';
	}

It relies on this function:

renovate/lib/modules/platform/azure/index.ts

Lines 361 to 379 in a581f7b

	async function getStatusCheck(branchName: string): Promise<GitStatus[]> {
	const azureApiGit = await azureApi.gitApi();
	const branch = await azureApiGit.getBranch(
	config.repoId,
	// TODO: fix undefined (#22198)
	getBranchNameWithoutRefsheadsPrefix(branchName)!,
	);
	// only grab the latest statuses, it will group any by context
	return azureApiGit.getStatuses(
	// TODO #22198
	branch.commit!.commitId!,
	config.repoId,
	undefined,
	undefined,
	undefined,
	true,
	);
	}

Like with other platforms it:

• Gets the branch: https://learn.microsoft.com/en-us/javascript/api/azure-devops-extension-api/gitrestclient#azure-devops-extension-api-gitrestclient-getbranch
• Extracts the commit.commitId from the result: https://learn.microsoft.com/en-us/javascript/api/azure-devops-extension-api/gitbranchstats
• Gets statuses for the commit ID of the branch: https://learn.microsoft.com/en-us/javascript/api/azure-devops-extension-api/gitrestclient#azure-devops-extension-api-gitrestclient-getstatuses

Theoretically instead:

• getPullRequest: https://learn.microsoft.com/en-us/javascript/api/azure-devops-extension-api/gitrestclient#azure-devops-extension-api-gitrestclient-getstatuses
• get lastMergeCommit from the results

Proposal:

• If no PR then we use the existing approach
• If there's a PR and no lastMergeCommit or it's the same as lastMergeSourceCommit then use that commit (should in theory be the same result as today)
• If there's a PR and lastMergeCommit exists then use it exclusively, or check both it and lastMergeSourceCommit and combine results?

Question:

• Onto which commit should Renovate place its internal status checks?