front_end/testing/TestIdGeneration.ts

// Copyright 2026 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

const replacements: Record<string, string|undefined> = {
  '\n': '_lf_',
  '\r': '_cr_',
  '\t': '_tab_',
  '\x00': '_null_',
  '\x07': '_bell_',
};

const nonPrintRegex = /[^\x20-\x7E]/ug;

function replaceNonPrintable(str: string) {
  return str.replace(nonPrintRegex, match => {
    return replacements[match] !== undefined ? replacements[match] : '';
  });
}

export function escapeTestIdBlock(block: string): string {
  return replaceNonPrintable(block.toLowerCase()).replace(/"/g, '_dblquote_').replace(/\s+/g, '_').replace(/:/g, '_');
}

/**
 * Build test ID is like the test ID used on the CLI but the path part of it is
 * an absolute path to the build dir.
 */
export function computeBuildTestId(file: string, titlePath: string[]) {
  const blocks = titlePath.map(escapeTestIdBlock);
  const caseName = blocks.join(':');
  const exactTestId = `${file}:${caseName}`;
  return exactTestId;
}

export function generateExactTestId(
    genDir: string,
    file: string,
    titlePath: string[],
    ): {
  exactTestId: string,
  coarseName: string,
  fineName: string,
  caseName: string,
} {
  const blocks = titlePath.map(escapeTestIdBlock);
  const caseName = blocks.join(':');

  const normalizedGenDir = genDir.replace(/\\/g, '/');
  const normalizedFile = file.replace(/\\/g, '/');

  let relativeSourceFileName = normalizedFile;
  if (normalizedFile.startsWith(normalizedGenDir)) {
    relativeSourceFileName = normalizedFile.substring(normalizedGenDir.length);
    if (relativeSourceFileName.startsWith('/')) {
      relativeSourceFileName = relativeSourceFileName.substring(1);
    }
  }

  relativeSourceFileName = relativeSourceFileName.replace(/\.js$/, '.ts');

  const parsedPath = relativeSourceFileName.split('/');
  const fineName = parsedPath.pop() || '';
  const coarseName = parsedPath.length > 0 ? `${parsedPath.join('/')}/` : '';
  const exactTestId = `${relativeSourceFileName}:${caseName}`;
  if (exactTestId.length >= 512) {
    throw new Error('Test ID is too long');
  }
  return {exactTestId, coarseName, fineName, caseName};
}

export function formatFailedTestsSummary(failedTestIds: Iterable<string>): string {
  const ids = Array.from(failedTestIds);
  if (ids.length === 0) {
    return '';
  }
  return `\nFailed tests (${ids.length}):\n${ids.map(id => `  ${id}`).join('\n')}\n\nTo rerun:\n  npm run test -- ${
      ids.join(' ')}\n\n`;
}