Run the following and observe output/result (numbers between parenthesis for easier reference, are not part of the command to execute): npm install grunt ignorefiles (1) grunt eslint # No errors and no warnings (2) grunt eslint --show-lint-warnings # Bunch of warnings, "Done", 0 return code (3) grunt eslint --max-lint-warnings=-1 # Same (4) grunt eslint --max-lint-warnings=0 # Bunch of warnings, "Aborted", non-zero return code (5) grunt eslint --max-lint-warnings=2000 # Bunch of warnings, "Done", 0 return code (6) grunt eslint --max-lint-warnings=100 # Bunch of warnings, "Aborted", non-zero return code In (4) and (6) it says something like "Warning: ESLint found too many warnings (maximum: 100) Use --force to continue." This will also work in plugins folders (in 3.9): pushd mod/forum (7) grunt eslint --max-lint-warnings=0 # Bunch of warnings, all them with forum files "Aborted", non-zero return code popd pushd mod/quiz (8) grunt eslint --max-lint-warnings=0 # Bunch of warnings, all them with quiz files "Aborted", non-zero return code popd This will work in 3.8: (9) pushd mod/forum/amd grunt eslint:amd --max-lint-warnings=0 # Bunch of warnings, all them with forum/amd files "Aborted", non-zero return code popd