Function ensureNoDuplicateConfigs

packages/jest-config/src/index.ts:268–302

(
  parsedConfigs: Array<ReadConfig>,
  projects: Config.GlobalConfig['projects'],
)

});

const ensureNoDuplicateConfigs = (
  parsedConfigs: Array<ReadConfig>,
  projects: Config.GlobalConfig['projects'],
) => {
  if (projects.length <= 1) {
    return;
  }

  const configPathMap = new Map();

  for (const config of parsedConfigs) {
    const {configPath} = config;

    if (configPathMap.has(configPath)) {
      const message = `Whoops! Two projects resolved to the same config path: ${chalk.bold(
        String(configPath),
      )}:

  Project 1: ${chalk.bold(projects[parsedConfigs.indexOf(config)])}
  Project 2: ${chalk.bold(
    projects[parsedConfigs.indexOf(configPathMap.get(configPath))],
  )}

This usually means that your ${chalk.bold(
        '"projects"',
      )} config includes a directory that doesn't have any configuration recognizable by Jest. Please fix it.
`;

      throw new Error(message);
    }
    if (configPath !== null) {
      configPathMap.set(configPath, config);
    }
  }
};

export interface ReadJestConfigOptions {
  /**