jestjs/jest · error · Error

Changed files must be set when running with -o.

Error message

Changed files must be set when running with -o.

What it means

Thrown by SearchSource._getTestPaths when globalConfig.onlyChanged is true (set by the -o / --onlyChanged CLI flag) but no changedFiles argument was passed to the method. The changed-file set is required to compute which tests cover modified source files.

Solutions

1. Compute changed files via jest-changed-files (getChangedFilesForRoots) and pass them as the changedFiles argument
2. If invoking programmatically, drop the onlyChanged flag and pass explicit test paths instead
3. When using the CLI, ensure you are inside a git/hg repo so changed files can be detected

Example fix

// before
searchSource.getTestPaths(
  { ...globalConfig, onlyChanged: true },
  projectConfig,
  // changedFiles omitted
);

// after
const { getChangedFilesForRoots } = require('jest-changed-files');
const changedFilesInfo = await getChangedFilesForRoots([projectConfig.rootDir], false);
await searchSource.getTestPaths(globalConfig, projectConfig, changedFilesInfo);

import { getChangedFilesForRoots } from 'jest-changed-files';
async function getTestPathsWithChanged(globalConfig, projectConfig, searchSource) {
  let changedFiles;
  if (globalConfig.onlyChanged) {
    changedFiles = await getChangedFilesForRoots([projectConfig.rootDir], false);
  }
  return searchSource.getTestPaths(globalConfig, projectConfig, changedFiles);
}

When it happens

Trigger: Programmatic invocation of SearchSource.getTestPaths / _getTestPaths with onlyChanged=true and changedFiles undefined. The CLI path normally supplies changedFiles from jest-changed-files; this is hit via the API or a misconfigured runner.

Common situations: Custom Jest runners/launchers that call SearchSource directly and forget to compute and pass changed files; test harnesses that enable --onlyChanged without wiring the SCM integration.

Related errors

• "cwd" must be an absolute path. cwd
• Filter did not return a valid test list
• file must export a function at
• Can't find a root directory while resolving a config file…
• Cannot find `global.gc` function. Please run node with…

AI-assisted analysis of jestjs/jest@8e6d128e4a (2026-08-10). Data as JSON: /api/errors/02b152dd251fabfb. Report an issue: GitHub.

Appendix: source

Thrown at packages/jest-core/src/SearchSource.ts:276

  async findTestRelatedToChangedFiles(
    changedFilesInfo: ChangedFiles,
    collectCoverage: boolean,
  ): Promise<SearchResult> {
    if (!hasSCM(changedFilesInfo)) {
      return {noSCM: true, tests: []};
    }
    const {changedFiles} = changedFilesInfo;
    return this.findRelatedTests(changedFiles, collectCoverage);
  }

  private async _getTestPaths(
    globalConfig: Config.GlobalConfig,
    projectConfig: Config.ProjectConfig,
    changedFiles?: ChangedFiles,
  ): Promise<SearchResult> {
    if (globalConfig.onlyChanged) {
      if (!changedFiles) {
        throw new Error('Changed files must be set when running with -o.');
      }

      return this.findTestRelatedToChangedFiles(
        changedFiles,
        globalConfig.collectCoverage,
      );
    }

    let paths = globalConfig.nonFlagArgs;

    if (globalConfig.findRelatedTests && 'win32' === os.platform()) {
      paths = this.filterPathsWin32(paths);
    }

    if (globalConfig.runTestsByPath && paths && paths.length > 0) {
      return this.findTestsByPaths(paths);
    } else if (globalConfig.findRelatedTests && paths && paths.length > 0) {
      return this.findRelatedTestsFromPattern(

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