ESLint or linter check failure

What this failure means

A linting or formatting check step (eslint, tslint, prettier) found violations in the source code and exited with a non-zero code, failing the CI step.

Symptoms

Faultline looks for one or more of these log fragments:

ESLint
eslint
Lint errors found
lint failed
error  Parsing error
problems (0 errors
tslint
prettier --check

Diagnosis

A linting or formatting check step (eslint, tslint, prettier) found violations in the source code and exited with a non-zero code, failing the CI step.

Fix steps

1. Run npx eslint . --fix locally to auto-fix fixable violations (formatting, import ordering, trailing commas).
2. Run npx prettier --write . for formatting violations that ESLint delegates to Prettier.
3. For rule violations that cannot be auto-fixed, address each error line manually — the output includes the rule name and a URL to the rule documentation.
4. To see the resolved configuration applied to a specific file: npx eslint --print-config path/to/file.ts — useful when a shared config override is unexpected.
5. If a new rule was enabled by a shared config update (e.g., eslint-config-company bumped): check the config package’s changelog and decide whether to fix violations or temporarily raise the rule to warn.
6. For @typescript-eslint errors: confirm parserOptions.project in .eslintrc points to the correct tsconfig.json — a missing project reference causes false positives.
7. For no-unused-vars on type imports: use import type syntax or add @typescript-eslint/no-unused-vars with varsIgnorePattern.

Validation

• npx eslint .
• npx eslint . —fix —dry-run

Why it matters

Lint failures happen when code is committed without running the linter locally, when a new ESLint rule is enabled in the shared config, or when a dependency update changes rule behaviour. Formatting failures occur when code is not formatted before commit.

Prevention

• Add a pre-commit hook with lint-staged to run ESLint on changed files before commit.
• Configure your editor to show ESLint and Prettier errors inline.
• Use eslint --max-warnings 0 in CI to fail on warnings as well as errors.

How Faultline detects it

Use faultline explain eslint-failure to see the full playbook.

faultline analyze build.log
faultline explain eslint-failure

Generated from playbooks/bundled/log/build/eslint-failure.yaml. Do not edit directly.