fail_on_changes

The behaviour of lefthook when files (tracked by git) are modified can set by modifying the fail_on_changes configuration parameter. The possible values are:

• never: never exit with a non-zero status if files were modified (default).
• always: always exit with a non-zero status if files were modified.
• ci: exit with a non-zero status only when CI environment variable is set. This can be useful when combined with stage_fixed to ensure a frictionless devX locally, and a robust CI.

# lefthook.yml
pre-commit:
  parallel: true
  fail_on_changes: "always"
  commands:
    lint:
      run: yarn lint
    test:
      run: yarn test