llm-api-compatibility.yml

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# SPDX-License-Identifier: Apache-2.0
#
# Licensed under the Apache License, Version 2.0 (the "License");
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#
# http://www.apache.org/licenses/LICENSE-2.0
#
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name: LLM API Compatibility

on:
  pull_request:
    types: [opened, edited, synchronize, reopened, labeled, unlabeled]

jobs:
  check-llm-api-compatibility:
    name: Check LLM API Compatibility Label
    runs-on: ubuntu-latest
    permissions:
      pull-requests: read
    steps:
      - name: Validate LLM API compatibility label
        uses: actions/github-script@v8
        with:
          script: |
            const referencePrefixes = [
              'tests/unittest/api_stability/references/',
              'tests/unittest/api_stability/references_committed/',
            ];
            // Keep these names in sync with the PR template and API-change guide.
            const compatibleApiLabel = 'api-compatible';
            const breakingApiLabel = 'api-breaking';

            const files = await github.paginate(github.rest.pulls.listFiles, {
              owner: context.repo.owner,
              repo: context.repo.repo,
              pull_number: context.payload.pull_request.number,
              per_page: 100,
            });

            const changedPaths = files
              .flatMap((file) => [file.filename, file.previous_filename].filter(Boolean));
            const apiReferenceChanged = changedPaths.some((path) =>
              referencePrefixes.some((prefix) => path.startsWith(prefix))
            );

            if (!apiReferenceChanged) {
              core.info('No API stability reference changes detected.');
              return;
            }

            const labelNames = new Set(
              (context.payload.pull_request.labels || []).map((label) => label.name)
            );
            const apiChangeLabels = [compatibleApiLabel, breakingApiLabel].filter((label) =>
              labelNames.has(label)
            );

            if (apiChangeLabels.length !== 1) {
              core.setFailed(
                'API stability reference files changed. Apply exactly one ' +
                `of these labels: '${compatibleApiLabel}' or '${breakingApiLabel}'.`
              );
              return;
            }

            if (
              apiChangeLabels[0] === breakingApiLabel &&
              !context.payload.pull_request.title.includes('BREAKING')
            ) {
              core.setFailed("Breaking LLM API changes must include 'BREAKING' in the PR title.");
              return;
            }

            core.info(`LLM API change label accepted: ${apiChangeLabels[0]}`);