labeler/__tests__/main.test.ts

import {
  jest,
  describe,
  it,
  test,
  expect,
  afterAll,
  beforeEach
} from '@jest/globals';
import path from 'path';
import {fileURLToPath} from 'url';
import fs from 'fs';

const __dirname = path.dirname(fileURLToPath(import.meta.url));

// Define mock functions before mocking modules
const setLabelsMock = jest.fn<any>();
const reposMock = jest.fn<any>();
const paginateMock = jest.fn<any>();
const getPullMock = jest.fn<any>().mockResolvedValue({data: {labels: []}});
const listFilesMergeMock = jest.fn<any>().mockReturnValue({});

const coreGetInputMock = jest.fn<any>();
const coreGetMultilineInputMock = jest.fn<any>();
const coreGetBooleanInputMock = jest.fn<any>();
const coreErrorMock = jest.fn<any>();
const coreWarningMock = jest.fn<any>();
const coreSetFailedMock = jest.fn<any>();
const setOutputSpy = jest.fn<any>();

const mockGithubContext: any = {
  payload: {
    pull_request: {
      number: 123,
      head: {ref: 'head-branch-name'},
      base: {ref: 'base-branch-name'}
    }
  },
  repo: {owner: 'monalisa', repo: 'helloworld'}
};

jest.unstable_mockModule('@actions/core', () => ({
  getInput: coreGetInputMock,
  getMultilineInput: coreGetMultilineInputMock,
  getBooleanInput: coreGetBooleanInputMock,
  setOutput: setOutputSpy,
  setFailed: coreSetFailedMock,
  error: coreErrorMock,
  warning: coreWarningMock,
  info: jest.fn(),
  debug: jest.fn()
}));

jest.unstable_mockModule('@actions/github', () => ({
  context: mockGithubContext,
  getOctokit: jest.fn(() => ({
    rest: {
      issues: {setLabels: setLabelsMock},
      repos: {getContent: reposMock},
      pulls: {
        get: getPullMock,
        listFiles: {endpoint: {merge: listFilesMergeMock}}
      }
    },
    paginate: paginateMock
  }))
}));

const {run} = await import('../src/labeler.js');

const readFileSyncMock = jest.spyOn(fs, 'readFileSync');
const existsSyncMock = jest.spyOn(fs, 'existsSync');

class HttpError extends Error {
  constructor(message: string) {
    super(message);
    this.name = 'HttpError';
  }
}

class NotFound extends Error {
  constructor(message: string) {
    super(message);
    this.name = 'NotFound';
  }
}

const yamlFixtures = {
  'branches.yml': fs.readFileSync('__tests__/fixtures/branches.yml'),
  'only_pdfs.yml': fs.readFileSync('__tests__/fixtures/only_pdfs.yml'),
  'not_supported.yml': fs.readFileSync('__tests__/fixtures/not_supported.yml'),
  'any_and_all.yml': fs.readFileSync('__tests__/fixtures/any_and_all.yml'),
  'mixed_labels.yml': fs.readFileSync('__tests__/fixtures/mixed_labels.yml'),
  'limit_0.yml': fs.readFileSync('__tests__/fixtures/limit_0.yml'),
  'limit_1.yml': fs.readFileSync('__tests__/fixtures/limit_1.yml'),
  'limit_2.yml': fs.readFileSync('__tests__/fixtures/limit_2.yml'),
  'limit_3.yml': fs.readFileSync('__tests__/fixtures/limit_3.yml'),
  'mixed_rules.yml': fs.readFileSync('__tests__/fixtures/mixed_rules.yml'),
  'max_files_5.yml': fs.readFileSync('__tests__/fixtures/max_files_5.yml'),
  'max_files_with_branch.yml': fs.readFileSync(
    '__tests__/fixtures/max_files_with_branch.yml'
  )
};

const configureInput = (
  mockInput: Partial<{
    'repo-token': string;
    'configuration-path': string;
    'sync-labels': boolean;
    dot: boolean;
    'pr-number': string[];
  }>
) => {
  coreGetInputMock.mockImplementation(
    (name: unknown) => mockInput[name as keyof typeof mockInput]
  );
  coreGetMultilineInputMock.mockImplementation(
    (name: unknown) => mockInput[name as keyof typeof mockInput]
  );
  coreGetBooleanInputMock.mockImplementation(
    (name: unknown) => mockInput[name as keyof typeof mockInput]
  );
};

afterAll(async () => {
  jest.restoreAllMocks();
});

describe('run', () => {
  beforeEach(() => {
    getPullMock.mockResolvedValue({data: {labels: []}} as any);
    mockGithubContext.payload.pull_request.head = {ref: 'head-branch-name'};
    mockGithubContext.payload.pull_request.base = {ref: 'base-branch-name'};
  });
  it('(with dot: false) adds labels to PRs that match our glob patterns', async () => {
    configureInput({});
    usingLabelerConfigYaml('only_pdfs.yml');
    mockGitHubResponseChangedFiles('foo.pdf');
    getPullMock.mockResolvedValue(<any>{
      data: {
        labels: []
      }
    });

    await run();

    expect(setLabelsMock).toHaveBeenCalledTimes(1);

    expect(setLabelsMock).toHaveBeenCalledWith({
      owner: 'monalisa',
      repo: 'helloworld',
      issue_number: 123,
      labels: ['touched-a-pdf-file']
    });
    expect(setOutputSpy).toHaveBeenCalledWith(
      'new-labels',
      'touched-a-pdf-file'
    );
    expect(setOutputSpy).toHaveBeenCalledWith(
      'all-labels',
      'touched-a-pdf-file'
    );
  });

  it('(with dot: true) adds labels to PRs that match our glob patterns', async () => {
    configureInput({dot: true});
    usingLabelerConfigYaml('only_pdfs.yml');
    mockGitHubResponseChangedFiles('.foo.pdf');
    getPullMock.mockResolvedValue(<any>{
      data: {
        labels: []
      }
    });

    await run();

    expect(setLabelsMock).toHaveBeenCalledTimes(1);
    expect(setLabelsMock).toHaveBeenCalledWith({
      owner: 'monalisa',
      repo: 'helloworld',
      issue_number: 123,
      labels: ['touched-a-pdf-file']
    });
    expect(setOutputSpy).toHaveBeenCalledWith(
      'new-labels',
      'touched-a-pdf-file'
    );
    expect(setOutputSpy).toHaveBeenCalledWith(
      'all-labels',
      'touched-a-pdf-file'
    );
  });

  it('(with dot: false) does not add labels to PRs that do not match our glob patterns', async () => {
    configureInput({});
    usingLabelerConfigYaml('only_pdfs.yml');
    mockGitHubResponseChangedFiles('.foo.pdf');
    getPullMock.mockResolvedValue(<any>{
      data: {
        labels: []
      }
    });

    await run();

    expect(setLabelsMock).toHaveBeenCalledTimes(0);
    expect(setOutputSpy).toHaveBeenCalledWith('new-labels', '');
    expect(setOutputSpy).toHaveBeenCalledWith('all-labels', '');
  });

  it('(with dot: true) does not add labels to PRs that do not match our glob patterns', async () => {
    configureInput({dot: true});
    usingLabelerConfigYaml('only_pdfs.yml');
    mockGitHubResponseChangedFiles('foo.txt');

    await run();

    expect(setLabelsMock).toHaveBeenCalledTimes(0);
  });

  it('does not add a label when the match config options are not supported', async () => {
    configureInput({});
    usingLabelerConfigYaml('not_supported.yml');
    await run();

    expect(setLabelsMock).toHaveBeenCalledTimes(0);
  });

  it('adds labels based on the branch names that match the regexp pattern', async () => {
    configureInput({});
    mockGithubContext.payload.pull_request.head = {ref: 'test/testing-time'};
    usingLabelerConfigYaml('branches.yml');
    await run();

    expect(setLabelsMock).toHaveBeenCalledTimes(1);
    expect(setLabelsMock).toHaveBeenCalledWith({
      owner: 'monalisa',
      repo: 'helloworld',
      issue_number: 123,
      labels: ['test-branch']
    });

    expect(setOutputSpy).toHaveBeenCalledWith('new-labels', 'test-branch');
    expect(setOutputSpy).toHaveBeenCalledWith('all-labels', 'test-branch');
  });

  it('adds multiple labels based on branch names that match different regexp patterns', async () => {
    configureInput({});
    mockGithubContext.payload.pull_request.head = {
      ref: 'test/feature/123'
    };
    usingLabelerConfigYaml('branches.yml');
    await run();

    expect(setLabelsMock).toHaveBeenCalledTimes(1);
    expect(setLabelsMock).toHaveBeenCalledWith({
      owner: 'monalisa',
      repo: 'helloworld',
      issue_number: 123,
      labels: ['test-branch', 'feature-branch']
    });

    expect(setOutputSpy).toHaveBeenCalledWith(
      'new-labels',
      'test-branch,feature-branch'
    );
    expect(setOutputSpy).toHaveBeenCalledWith(
      'all-labels',
      'test-branch,feature-branch'
    );
  });

  it('can support multiple branches by batching', async () => {
    configureInput({});
    mockGithubContext.payload.pull_request.head = {ref: 'fix/123'};
    usingLabelerConfigYaml('branches.yml');
    await run();

    expect(setLabelsMock).toHaveBeenCalledTimes(1);
    expect(setLabelsMock).toHaveBeenCalledWith({
      owner: 'monalisa',
      repo: 'helloworld',
      issue_number: 123,
      labels: ['bug-branch']
    });

    expect(setOutputSpy).toHaveBeenCalledWith('new-labels', 'bug-branch');
    expect(setOutputSpy).toHaveBeenCalledWith('all-labels', 'bug-branch');
  });

  it('can support multiple branches by providing an array', async () => {
    configureInput({});
    mockGithubContext.payload.pull_request.head = {ref: 'array/123'};
    usingLabelerConfigYaml('branches.yml');
    await run();

    expect(setLabelsMock).toHaveBeenCalledTimes(1);
    expect(setLabelsMock).toHaveBeenCalledWith({
      owner: 'monalisa',
      repo: 'helloworld',
      issue_number: 123,
      labels: ['array-branch']
    });

    expect(setOutputSpy).toHaveBeenCalledWith('new-labels', 'array-branch');
    expect(setOutputSpy).toHaveBeenCalledWith('all-labels', 'array-branch');
  });

  it('adds a label when matching any and all patterns are provided', async () => {
    configureInput({});
    usingLabelerConfigYaml('any_and_all.yml');
    mockGitHubResponseChangedFiles('tests/test.ts');
    await run();

    expect(setLabelsMock).toHaveBeenCalledTimes(1);
    expect(setLabelsMock).toHaveBeenCalledWith({
      owner: 'monalisa',
      repo: 'helloworld',
      issue_number: 123,
      labels: ['tests']
    });

    expect(setOutputSpy).toHaveBeenCalledWith('new-labels', 'tests');
    expect(setOutputSpy).toHaveBeenCalledWith('all-labels', 'tests');
  });

  it('does not add a label when not all any and all patterns are matched', async () => {
    configureInput({});
    usingLabelerConfigYaml('any_and_all.yml');
    mockGitHubResponseChangedFiles('tests/requirements.txt');
    await run();

    expect(setLabelsMock).toHaveBeenCalledTimes(0);
  });

  it('(with sync-labels: true) it deletes preexisting PR labels that no longer match the glob pattern', async () => {
    configureInput({
      'repo-token': 'foo',
      'configuration-path': 'bar',
      'sync-labels': true
    });

    usingLabelerConfigYaml('only_pdfs.yml');
    mockGitHubResponseChangedFiles('foo.txt');
    getPullMock.mockResolvedValue(<any>{
      data: {
        labels: [{name: 'touched-a-pdf-file'}, {name: 'manually-added'}]
      }
    });

    await run();

    expect(setLabelsMock).toHaveBeenCalledTimes(1);
    expect(setLabelsMock).toHaveBeenCalledWith({
      owner: 'monalisa',
      repo: 'helloworld',
      issue_number: 123,
      labels: ['manually-added']
    });

    expect(setOutputSpy).toHaveBeenCalledWith('new-labels', '');
    expect(setOutputSpy).toHaveBeenCalledWith('all-labels', 'manually-added');
  });

  it('(with sync-labels: false) it issues no delete calls even when there are preexisting PR labels that no longer match the glob pattern', async () => {
    configureInput({
      'repo-token': 'foo',
      'configuration-path': 'bar',
      'sync-labels': false
    });

    usingLabelerConfigYaml('only_pdfs.yml');
    mockGitHubResponseChangedFiles('foo.txt');
    getPullMock.mockResolvedValue(<any>{
      data: {
        labels: [{name: 'touched-a-pdf-file'}, {name: 'manually-added'}]
      }
    });

    await run();

    expect(setLabelsMock).toHaveBeenCalledTimes(0);
    expect(setOutputSpy).toHaveBeenCalledWith('new-labels', '');
    expect(setOutputSpy).toHaveBeenCalledWith(
      'all-labels',
      'touched-a-pdf-file,manually-added'
    );
  });

  it('(with sync-labels: false) it only logs the excess labels', async () => {
    configureInput({
      'repo-token': 'foo',
      'configuration-path': 'bar',
      'sync-labels': false
    });

    usingLabelerConfigYaml('only_pdfs.yml');
    mockGitHubResponseChangedFiles('foo.pdf');

    const existingLabels = Array.from({length: 100}).map((_, idx) => ({
      name: `existing-label-${idx}`
    }));
    getPullMock.mockResolvedValue(<any>{
      data: {
        labels: existingLabels
      }
    });

    await run();

    expect(setLabelsMock).toHaveBeenCalledTimes(0);

    expect(coreWarningMock).toHaveBeenCalledTimes(1);
    expect(coreWarningMock).toHaveBeenCalledWith(
      'Maximum of 100 labels allowed. Excess labels: touched-a-pdf-file',
      {title: 'Label limit for a PR exceeded'}
    );
    const allLabels: string = existingLabels.map(i => i.name).join(',');
    expect(setOutputSpy).toHaveBeenCalledWith('new-labels', '');
    expect(setOutputSpy).toHaveBeenCalledWith('all-labels', allLabels);
  });

  it('(with pr-number: array of one item, uses the PR number specified in the parameters', async () => {
    configureInput({
      'repo-token': 'foo',
      'configuration-path': 'bar',
      'pr-number': ['104']
    });

    usingLabelerConfigYaml('only_pdfs.yml');
    mockGitHubResponseChangedFiles('foo.pdf');

    getPullMock.mockResolvedValue(<any>{
      data: {
        labels: [{name: 'manually-added'}]
      }
    });

    await run();
    expect(setLabelsMock).toHaveBeenCalledTimes(1);
    expect(setLabelsMock).toHaveBeenCalledWith({
      owner: 'monalisa',
      repo: 'helloworld',
      issue_number: 104,
      labels: ['manually-added', 'touched-a-pdf-file']
    });
    expect(setOutputSpy).toHaveBeenCalledWith(
      'new-labels',
      'touched-a-pdf-file'
    );
    expect(setOutputSpy).toHaveBeenCalledWith(
      'all-labels',
      'manually-added,touched-a-pdf-file'
    );
  });

  it('(with pr-number: array of two items, uses the PR number specified in the parameters', async () => {
    configureInput({
      'repo-token': 'foo',
      'configuration-path': 'bar',
      'pr-number': ['104', '150']
    });

    usingLabelerConfigYaml('only_pdfs.yml');
    mockGitHubResponseChangedFiles('foo.pdf');

    getPullMock.mockResolvedValueOnce(<any>{
      data: {
        labels: [{name: 'manually-added'}]
      }
    });

    getPullMock.mockResolvedValueOnce(<any>{
      data: {
        labels: []
      }
    });

    await run();
    expect(setLabelsMock).toHaveBeenCalledTimes(2);
    expect(setLabelsMock).toHaveBeenCalledWith({
      owner: 'monalisa',
      repo: 'helloworld',
      issue_number: 104,
      labels: ['manually-added', 'touched-a-pdf-file']
    });
    expect(setLabelsMock).toHaveBeenCalledWith({
      owner: 'monalisa',
      repo: 'helloworld',
      issue_number: 150,
      labels: ['touched-a-pdf-file']
    });
    expect(setOutputSpy).toHaveBeenCalledWith(
      'new-labels',
      'touched-a-pdf-file'
    );
    expect(setOutputSpy).toHaveBeenCalledWith(
      'all-labels',
      'manually-added,touched-a-pdf-file'
    );
  });

  it('(with pr-number: non-numeric string) warns and makes no API call', async () => {
    configureInput({
      'repo-token': 'foo',
      'configuration-path': 'bar',
      'pr-number': ['abc']
    });

    usingLabelerConfigYaml('only_pdfs.yml');

    await run();

    expect(coreWarningMock).toHaveBeenCalledWith(
      "'abc' is not a valid pull request number"
    );
    expect(getPullMock).not.toHaveBeenCalled();
    expect(setLabelsMock).not.toHaveBeenCalled();
  });

  it('(with pr-number: negative number) warns and makes no API call', async () => {
    configureInput({
      'repo-token': 'foo',
      'configuration-path': 'bar',
      'pr-number': ['-1']
    });

    usingLabelerConfigYaml('only_pdfs.yml');

    await run();

    expect(coreWarningMock).toHaveBeenCalledWith(
      "'-1' is not a valid pull request number"
    );
    expect(getPullMock).not.toHaveBeenCalled();
    expect(setLabelsMock).not.toHaveBeenCalled();
  });

  it('(with pr-number: zero) warns and makes no API call', async () => {
    configureInput({
      'repo-token': 'foo',
      'configuration-path': 'bar',
      'pr-number': ['0']
    });

    usingLabelerConfigYaml('only_pdfs.yml');

    await run();

    expect(coreWarningMock).toHaveBeenCalledWith(
      "'0' is not a valid pull request number"
    );
    expect(getPullMock).not.toHaveBeenCalled();
    expect(setLabelsMock).not.toHaveBeenCalled();
  });

  it('(with pr-number: number with internal space) warns and makes no API call', async () => {
    configureInput({
      'repo-token': 'foo',
      'configuration-path': 'bar',
      'pr-number': ['10 4']
    });

    usingLabelerConfigYaml('only_pdfs.yml');

    await run();

    expect(coreWarningMock).toHaveBeenCalledWith(
      "'10 4' is not a valid pull request number"
    );
    expect(getPullMock).not.toHaveBeenCalled();
    expect(setLabelsMock).not.toHaveBeenCalled();
  });

  it('(with pr-number: number with trailing non-numeric chars) warns and makes no API call', async () => {
    configureInput({
      'repo-token': 'foo',
      'configuration-path': 'bar',
      'pr-number': ['104abc']
    });

    usingLabelerConfigYaml('only_pdfs.yml');

    await run();

    expect(coreWarningMock).toHaveBeenCalledWith(
      "'104abc' is not a valid pull request number"
    );
    expect(getPullMock).not.toHaveBeenCalled();
    expect(setLabelsMock).not.toHaveBeenCalled();
  });

  it('(with pr-number: valid number with surrounding whitespace) trims and processes correctly', async () => {
    configureInput({
      'repo-token': 'foo',
      'configuration-path': 'bar',
      'pr-number': [' 104 ']
    });

    usingLabelerConfigYaml('only_pdfs.yml');
    mockGitHubResponseChangedFiles('foo.pdf');
    getPullMock.mockResolvedValue(<any>{data: {labels: []}});

    await run();

    expect(getPullMock).toHaveBeenCalled();
    expect(coreWarningMock).not.toHaveBeenCalledWith(
      expect.stringContaining('is not a valid pull request number')
    );
  });

  it('(with pr-number: string with carriage return) sanitizes CR as \\x0d in warning', async () => {
    configureInput({
      'repo-token': 'foo',
      'configuration-path': 'bar',
      'pr-number': ['abc\rdef']
    });

    usingLabelerConfigYaml('only_pdfs.yml');

    await run();

    expect(coreWarningMock).toHaveBeenCalledWith(
      "'abc\\x0ddef' is not a valid pull request number (non-printable characters were escaped as \\xNN)"
    );
    expect(getPullMock).not.toHaveBeenCalled();
    expect(setLabelsMock).not.toHaveBeenCalled();
  });

  it('(with pr-number: string with tab) sanitizes tab as \\x09 in warning', async () => {
    configureInput({
      'repo-token': 'foo',
      'configuration-path': 'bar',
      'pr-number': ['abc\tdef']
    });

    usingLabelerConfigYaml('only_pdfs.yml');

    await run();

    expect(coreWarningMock).toHaveBeenCalledWith(
      "'abc\\x09def' is not a valid pull request number (non-printable characters were escaped as \\xNN)"
    );
    expect(getPullMock).not.toHaveBeenCalled();
    expect(setLabelsMock).not.toHaveBeenCalled();
  });

  it('(with pr-number: string with ANSI escape sequence) sanitizes ESC byte as \\x1b in warning', async () => {
    configureInput({
      'repo-token': 'foo',
      'configuration-path': 'bar',
      'pr-number': ['abc\x1b[31mINJECTED\x1b[0m']
    });

    usingLabelerConfigYaml('only_pdfs.yml');

    await run();

    expect(coreWarningMock).toHaveBeenCalledWith(
      "'abc\\x1b[31mINJECTED\\x1b[0m' is not a valid pull request number (non-printable characters were escaped as \\xNN)"
    );
    expect(getPullMock).not.toHaveBeenCalled();
    expect(setLabelsMock).not.toHaveBeenCalled();
  });

  it('(with pr-number: mix of valid and invalid) processes valid, skips invalid with warning', async () => {
    configureInput({
      'repo-token': 'foo',
      'configuration-path': 'bar',
      'pr-number': ['104', 'abc']
    });

    usingLabelerConfigYaml('only_pdfs.yml');
    mockGitHubResponseChangedFiles('foo.pdf');

    getPullMock.mockResolvedValue(<any>{
      data: {labels: []}
    });

    await run();

    expect(coreWarningMock).toHaveBeenCalledWith(
      "'abc' is not a valid pull request number"
    );
    expect(setLabelsMock).toHaveBeenCalledTimes(1);
    expect(setLabelsMock).toHaveBeenCalledWith({
      owner: 'monalisa',
      repo: 'helloworld',
      issue_number: 104,
      labels: ['touched-a-pdf-file']
    });
  });

  it('does not add labels to PRs that have no changed files', async () => {
    usingLabelerConfigYaml('only_pdfs.yml');
    mockGitHubResponseChangedFiles();

    await run();

    expect(setLabelsMock).toHaveBeenCalledTimes(0);
  });

  describe('changed-files-labels-limit', () => {
    it('applies all labels when count is within limit', async () => {
      configureInput({});
      mockGithubContext.payload.pull_request.head = {ref: 'main'};
      usingLabelerConfigYaml('limit_3.yml');
      mockGitHubResponseChangedFiles(
        'components/a/file.ts',
        'components/b/file.ts'
      );
      getPullMock.mockResolvedValue(<any>{
        data: {labels: []}
      });

      await run();

      expect(setLabelsMock).toHaveBeenCalledTimes(1);
      expect(setLabelsMock).toHaveBeenCalledWith({
        owner: 'monalisa',
        repo: 'helloworld',
        issue_number: 123,
        labels: ['component-a', 'component-b']
      });
    });

    it('skips changed-files labels when count exceeds limit', async () => {
      configureInput({});
      mockGithubContext.payload.pull_request.head = {ref: 'main'};
      usingLabelerConfigYaml('limit_2.yml');
      mockGitHubResponseChangedFiles(
        'components/a/file.ts',
        'components/b/file.ts',
        'components/c/file.ts'
      );
      getPullMock.mockResolvedValue(<any>{
        data: {labels: []}
      });

      await run();

      // No labels should be applied since changed-files labels exceed limit
      expect(setLabelsMock).toHaveBeenCalledTimes(0);
    });

    it('still applies branch-based labels when changed-files limit is exceeded', async () => {
      configureInput({});
      mockGithubContext.payload.pull_request.head = {ref: 'test/some-feature'};
      usingLabelerConfigYaml('limit_1.yml');
      mockGitHubResponseChangedFiles(
        'components/a/file.ts',
        'components/b/file.ts',
        'components/c/file.ts'
      );
      getPullMock.mockResolvedValue(<any>{
        data: {labels: []}
      });

      await run();

      // Only the branch-based label should be applied
      expect(setLabelsMock).toHaveBeenCalledTimes(1);
      expect(setLabelsMock).toHaveBeenCalledWith({
        owner: 'monalisa',
        repo: 'helloworld',
        issue_number: 123,
        labels: ['test-branch']
      });
    });

    it('applies all labels when no limit is set', async () => {
      configureInput({});
      mockGithubContext.payload.pull_request.head = {ref: 'main'};
      usingLabelerConfigYaml('mixed_labels.yml');
      mockGitHubResponseChangedFiles(
        'components/a/file.ts',
        'components/b/file.ts',
        'components/c/file.ts',
        'components/d/file.ts'
      );
      getPullMock.mockResolvedValue(<any>{
        data: {labels: []}
      });

      await run();

      expect(setLabelsMock).toHaveBeenCalledTimes(1);
      expect(setLabelsMock).toHaveBeenCalledWith({
        owner: 'monalisa',
        repo: 'helloworld',
        issue_number: 123,
        labels: ['component-a', 'component-b', 'component-c', 'component-d']
      });
    });

    it('does not count preexisting labels toward the limit', async () => {
      configureInput({});
      mockGithubContext.payload.pull_request.head = {ref: 'main'};
      usingLabelerConfigYaml('limit_2.yml');
      mockGitHubResponseChangedFiles(
        'components/a/file.ts',
        'components/b/file.ts',
        'components/c/file.ts',
        'components/d/file.ts'
      );
      getPullMock.mockResolvedValue(<any>{
        data: {labels: [{name: 'component-a'}, {name: 'component-b'}]}
      });

      await run();

      // component-a and component-b are preexisting, so only 2 new labels (c, d) would be added
      // which equals the limit of 2, so labels should be applied
      expect(setLabelsMock).toHaveBeenCalledTimes(1);
      expect(setLabelsMock).toHaveBeenCalledWith({
        owner: 'monalisa',
        repo: 'helloworld',
        issue_number: 123,
        labels: ['component-a', 'component-b', 'component-c', 'component-d']
      });
    });

    it('skips new labels when new count exceeds limit even with preexisting', async () => {
      configureInput({});
      mockGithubContext.payload.pull_request.head = {ref: 'main'};
      usingLabelerConfigYaml('limit_2.yml');
      mockGitHubResponseChangedFiles(
        'components/a/file.ts',
        'components/b/file.ts',
        'components/c/file.ts',
        'components/d/file.ts'
      );
      getPullMock.mockResolvedValue(<any>{
        data: {labels: [{name: 'component-a'}]}
      });

      await run();

      // component-a is preexisting, so 3 new labels (b, c, d) would be added
      // which exceeds the limit of 2, so no new changed-files labels are applied
      expect(setLabelsMock).toHaveBeenCalledTimes(0);
    });

    it('applies labels when new count equals the limit', async () => {
      configureInput({});
      mockGithubContext.payload.pull_request.head = {ref: 'main'};
      usingLabelerConfigYaml('limit_2.yml');
      mockGitHubResponseChangedFiles(
        'components/a/file.ts',
        'components/b/file.ts'
      );
      getPullMock.mockResolvedValue(<any>{
        data: {labels: []}
      });

      await run();

      expect(setLabelsMock).toHaveBeenCalledTimes(1);
      expect(setLabelsMock).toHaveBeenCalledWith({
        owner: 'monalisa',
        repo: 'helloworld',
        issue_number: 123,
        labels: ['component-a', 'component-b']
      });
    });

    it('skips all changed-files labels when limit is 0', async () => {
      configureInput({});
      mockGithubContext.payload.pull_request.head = {ref: 'test/some-feature'};
      usingLabelerConfigYaml('limit_0.yml');
      mockGitHubResponseChangedFiles('components/a/file.ts');
      getPullMock.mockResolvedValue(<any>{
        data: {labels: []}
      });

      await run();

      // With limit 0, only branch-based labels should be applied
      expect(setLabelsMock).toHaveBeenCalledTimes(1);
      expect(setLabelsMock).toHaveBeenCalledWith({
        owner: 'monalisa',
        repo: 'helloworld',
        issue_number: 123,
        labels: ['test-branch']
      });
    });

    it('treats labels with mixed rules as changed-files labels', async () => {
      // A label that has both branch and changed-files rules is considered
      // a "changed-files label" and subject to the limit, even if it matches
      // via the branch rule
      configureInput({});
      mockGithubContext.payload.pull_request.head = {ref: 'test/some-feature'};
      usingLabelerConfigYaml('mixed_rules.yml');
      mockGitHubResponseChangedFiles('unrelated/file.ts');
      getPullMock.mockResolvedValue(<any>{
        data: {labels: []}
      });

      await run();

      // The mixed-label matches via branch rule but is still subject to limit
      // because it contains a changed-files rule in its definition.
      // Only pure-branch-label should be applied.
      expect(setLabelsMock).toHaveBeenCalledTimes(1);
      expect(setLabelsMock).toHaveBeenCalledWith({
        owner: 'monalisa',
        repo: 'helloworld',
        issue_number: 123,
        labels: ['pure-branch-label']
      });
    });
  });

  describe('max-files-changed', () => {
    it('applies labels when changed files count is within limit', async () => {
      configureInput({});
      mockGithubContext.payload.pull_request.head = {ref: 'main'};
      usingLabelerConfigYaml('max_files_5.yml');
      mockGitHubResponseChangedFiles(
        'components/a/file.ts',
        'components/b/file.ts',
        'components/c/file.ts'
      );
      getPullMock.mockResolvedValue(<any>{
        data: {labels: []}
      });

      await run();

      expect(setLabelsMock).toHaveBeenCalledTimes(1);
      expect(setLabelsMock).toHaveBeenCalledWith({
        owner: 'monalisa',
        repo: 'helloworld',
        issue_number: 123,
        labels: ['component-a', 'component-b', 'component-c']
      });
    });

    it('skips file-based labels when changed files exceed limit', async () => {
      configureInput({});
      mockGithubContext.payload.pull_request.head = {ref: 'main'};
      usingLabelerConfigYaml('max_files_5.yml');
      mockGitHubResponseChangedFiles(
        'components/a/file1.ts',
        'components/a/file2.ts',
        'components/b/file1.ts',
        'components/b/file2.ts',
        'components/c/file1.ts',
        'components/c/file2.ts' // 6 files > limit of 5
      );
      getPullMock.mockResolvedValue(<any>{
        data: {labels: []}
      });

      await run();

      // No labels should be applied since changed files exceed limit
      expect(setLabelsMock).toHaveBeenCalledTimes(0);
    });

    it('applies labels when changed files count equals limit', async () => {
      configureInput({});
      mockGithubContext.payload.pull_request.head = {ref: 'main'};
      usingLabelerConfigYaml('max_files_5.yml');
      mockGitHubResponseChangedFiles(
        'components/a/file1.ts',
        'components/a/file2.ts',
        'components/b/file1.ts',
        'components/b/file2.ts',
        'components/c/file.ts' // exactly 5 files = limit
      );
      getPullMock.mockResolvedValue(<any>{
        data: {labels: []}
      });

      await run();

      expect(setLabelsMock).toHaveBeenCalledTimes(1);
      expect(setLabelsMock).toHaveBeenCalledWith({
        owner: 'monalisa',
        repo: 'helloworld',
        issue_number: 123,
        labels: ['component-a', 'component-b', 'component-c']
      });
    });

    it('still applies branch-based labels when max-files-changed is exceeded', async () => {
      configureInput({});
      mockGithubContext.payload.pull_request.head = {ref: 'test/some-feature'};
      usingLabelerConfigYaml('max_files_with_branch.yml');
      mockGitHubResponseChangedFiles(
        'components/a/file1.ts',
        'components/a/file2.ts',
        'components/b/file1.ts',
        'components/b/file2.ts' // 4 files > limit of 3
      );
      getPullMock.mockResolvedValue(<any>{
        data: {labels: []}
      });

      await run();

      // Only the branch-based label should be applied
      expect(setLabelsMock).toHaveBeenCalledTimes(1);
      expect(setLabelsMock).toHaveBeenCalledWith({
        owner: 'monalisa',
        repo: 'helloworld',
        issue_number: 123,
        labels: ['test-branch']
      });
    });

    it('preserves preexisting changed-files labels with sync-labels when max-files-changed is exceeded', async () => {
      configureInput({'sync-labels': true});
      mockGithubContext.payload.pull_request.head = {ref: 'main'};
      usingLabelerConfigYaml('max_files_5.yml');
      mockGitHubResponseChangedFiles(
        'unrelated/file1.ts',
        'unrelated/file2.ts',
        'unrelated/file3.ts',
        'unrelated/file4.ts',
        'unrelated/file5.ts',
        'unrelated/file6.ts' // 6 files > limit of 5
      );
      getPullMock.mockResolvedValue(<any>{
        data: {labels: [{name: 'component-a'}]} // preexisting label
      });

      await run();

      // No setLabels call because labels should remain unchanged
      // (component-a is preserved, not removed by sync-labels)
      expect(setLabelsMock).toHaveBeenCalledTimes(0);
    });
  });

  it('should use local configuration file if it exists', async () => {
    const configFile = 'only_pdfs.yml';
    const configFilePath = path.join(__dirname, 'fixtures', configFile);
    mockGitHubResponseChangedFiles('foo.pdf');
    const readFileSyncOptions = {encoding: 'utf8'};

    configureInput({
      'configuration-path': configFilePath
    });
    await run();

    expect(existsSyncMock).toHaveBeenCalledWith(configFilePath);
    expect(readFileSyncMock).toHaveBeenCalledWith(
      configFilePath,
      readFileSyncOptions
    );
    expect(reposMock).not.toHaveBeenCalled();
  });

  it('should fetch configuration file from API if it does not exist locally', async () => {
    const configFilePath = 'non_existed_path/labeler.yml';
    mockGitHubResponseChangedFiles('foo.pdf');
    configureInput({
      'configuration-path': configFilePath
    });
    await run();
    expect(existsSyncMock).toHaveBeenCalledWith(configFilePath);
    expect(readFileSyncMock).not.toHaveBeenCalled();
    expect(reposMock).toHaveBeenCalled();
  });

  test.each([
    [new HttpError('Error message')],
    [new NotFound('Error message')]
  ])(
    'should warn if configuration file could not be fetched through the API, log error and fail the action',
    async error => {
      const configFilePath = 'non_existed_path/labeler.yml';
      reposMock.mockImplementation(() => {
        throw error;
      });
      const warningMessage = `The config file was not found at ${configFilePath}. Make sure it exists and that this action has the correct access rights.`;
      mockGitHubResponseChangedFiles('foo.pdf');
      configureInput({
        'configuration-path': configFilePath
      });

      await run();

      expect(coreWarningMock).toHaveBeenCalledWith(warningMessage);
      expect(coreErrorMock).toHaveBeenCalledWith(error);
      expect(coreSetFailedMock).toHaveBeenCalledWith(error.message);
    }
  );
});

function usingLabelerConfigYaml(fixtureName: keyof typeof yamlFixtures): void {
  reposMock.mockResolvedValue(<any>{
    data: {content: yamlFixtures[fixtureName], encoding: 'utf8'}
  });
}

function mockGitHubResponseChangedFiles(...files: string[]): void {
  const returnValue = files.map(f => ({filename: f}));
  paginateMock.mockReturnValue(<any>returnValue);
}