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_',
  '"': '_dblquote_',
};

const nonPrintRegex = /\p{C}|"/gu;

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(/\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};
}