Paths: File paths (

shared/

,

references/

,

../ln-*

) are relative to skills repo root. If not found at CWD, locate this SKILL.md directory and go up one level for repo root. If

shared/

is missing, fetch files via WebFetch from

https://raw.githubusercontent.com/levnikolaevich/claude-code-skills/master/skills/{path}

.

ln-741-linter-configurator

Type: L3 Worker Category: 7XX Project Bootstrap

Configures code linting, formatting, and type checking tools for TypeScript, Python, and .NET projects.

Purpose & Scope

Does:

• Detects which linter stack to configure based on project type
• Checks for existing linter configurations
• Generates appropriate config files from templates
• Installs required dependencies (always latest versions, no pinning)
• Generates unified lint script (

  scripts/lint.sh

  )
• Verifies all linters run without errors

Does NOT:

• Configure pre-commit hooks (separate worker)
• Set up test infrastructure (separate worker)
• Modify source code

Supported Stacks

eslint.config.ts

.prettierrc

.editorconfig

Directory.Build.props

ruff.toml

mypy.toml

pyproject.toml

Phase 1: Check Existing Configuration

Before generating configs, check what already exists.

Files to Check:

eslint.config.*

.eslintrc*

.prettierrc*

prettier.config.*

.editorconfig

Directory.Build.props

ruff.toml

pyproject.toml

mypy.toml

mypy.ini

pyproject.toml [tool.mypy]

Decision Logic:

1. If no config exists: CREATE from template
2. If config exists but incomplete (fewer rules/tools than template): EXTEND to match template
3. If config matches template: SKIP (inform user)

Completeness Check (Python):

select

ruff_template.toml

tests/**/*.py

strict = true

scripts/lint.sh

Phase 2: Generate Configuration

Use templates from references/ folder. Customize placeholders based on project.

TypeScript:

1. Copy

   eslint_template.ts

   to project root as

   eslint.config.ts

2. Copy

   prettier_template.json

   as

   .prettierrc

3. Add scripts to

   package.json

   :

   • "lint": "eslint ."

   • "lint:fix": "eslint . --fix"

   • "format": "prettier --write ."

   • "format:check": "prettier --check ."

   • "typecheck": "tsc --noEmit"

   • "lint:all": "npm run typecheck && npm run lint && npm run format:check"

4. For React projects: uncomment React sections in template

.NET:

1. Copy

   editorconfig_template.ini

   as

   .editorconfig

2. Copy

   directory_build_props_template.xml

   as

   Directory.Build.props

3. Ensure analyzers are included (SDK 5+ includes them by default)

Python:

1. Copy

   ruff_template.toml

   as

   ruff.toml

   • OR merge into existing

     pyproject.toml

     under

     [tool.ruff]

2. Copy

   mypy_template.toml

   as

   mypy.toml

   • OR merge into existing

     pyproject.toml

     under

     [tool.mypy]

3. Update

   known-first-party

   in isort config to match project package name
4. Update

   files

   in mypy config to match project source directories
5. Generate advanced tool configs in

   pyproject.toml

   :

   • [tool.importlinter]

     from

     importlinter_template.toml

     -- adapt

     root_packages

     and contracts to project layer structure

   • [tool.vulture]

     from

     vulture_template.toml

     -- adapt

     paths

     to project source directory

   • [tool.deptry]

     from

     deptry_template.toml

     -- adapt

     extend_exclude

6. Generate

   .editorconfig

   from

   editorconfig_template.ini

   -- adapt

   max_line_length

   to match ruff

   line-length

Phase 3: Install Dependencies

Install required packages. Always install latest versions — no version pinning.

TypeScript:

npm install -D eslint @eslint/js typescript-eslint eslint-config-prettier prettier eslint-plugin-unicorn jiti

For React projects, also install:

npm install -D eslint-plugin-react eslint-plugin-react-hooks

Note on jiti: Required for

eslint.config.ts

on Node.js < 22.10. On Node.js 22.10+ TypeScript configs are supported natively.

.NET:

• Analyzers included in SDK 5+ — no separate install needed

Python:

uv add --dev ruff mypy import-linter deptry vulture pip-audit

# OR without uv:
pip install ruff mypy import-linter deptry vulture pip-audit

Phase 4: Generate Lint Script

Generate

scripts/lint.sh

lint_script_template.sh

1. Copy

   lint_script_template.sh

   to

   scripts/lint.sh

2. Uncomment ALL check lines matching detected stack -- both basic AND advanced tools:

3. Set

   TOTAL

   to match active checks count
4. Uncomment matching auto-fix commands in

   --fix

   block
5. Make executable:

   chmod +x scripts/lint.sh

6. For TypeScript: ensure

   "lint:all"

   script exists in

   package.json

Phase 5: Verify Setup

After configuration, verify everything works.

TypeScript:

npx tsc --noEmit
npx eslint .
npx prettier --check .

.NET:

dotnet format --verify-no-changes

Python:

ruff check .
ruff format --check .
mypy

Unified verification:

bash scripts/lint.sh

Expected: Exit code 0 for all checks.

On Failure: Check error output, adjust config, re-verify.

Phase 6: Fix Lint Errors

After generating all configs and installing tools, run

bash scripts/lint.sh --all

1. Run

   bash scripts/lint.sh --fix

   to auto-fix what ruff can
2. Fix remaining errors manually (file by file)
3. For C901 (complexity) on functions that cannot be refactored now: add

   # noqa: C901

4. For deptry false positives: add

   [tool.deptry.per_rule_ignores]

   entries
5. Repeat until

   bash scripts/lint.sh

   passes with 0 failures

Critical Rules

RULE 1: Always include

eslint-config-prettier

(last in config) when using ESLint + Prettier together.

RULE 2: Use ESLint flat config format (

eslint.config.ts

), NOT legacy

.eslintrc

.

RULE 3: Ruff replaces Black, isort, flake8, and many other Python tools. Do NOT install them separately.

RULE 4: Never disable strict TypeScript rules without documented reason.

RULE 5: Always run mypy alongside Ruff for Python projects. Ruff handles style/bugs, mypy handles type safety.

RULE 6: Use

recommendedTypeChecked

as ESLint default, not just

recommended

. Downgrade individual rules if needed.

RULE 7: Never pin dependency versions in install commands -- always install latest.

RULE 8: Advanced static analysis tools (import-linter, deptry, vulture, pip-audit) are MANDATORY for Python projects, not optional.

Monitor (2.1.98+): When lint/typecheck verification commands expected >30s, use

Monitor

Bash(run_in_background=true)

Definition of Done

• Appropriate config files created for detected stack
• Dependencies installed (latest versions)

• scripts/lint.sh

  generated with correct checks for stack
• Lint command runs without errors on project source
• Format command runs without errors
• Type checker runs without errors (mypy for Python, tsc for TypeScript)
• No ESLint/Prettier conflicts (eslint-config-prettier installed)
• Advanced tools installed and configured (import-linter, deptry, vulture, pip-audit)

• scripts/lint.sh

  runs ALL checks (7 for Python) with exit code 0

• .editorconfig

  created with settings matching ruff config
• User informed of available lint/format commands

Reference Files

Error Handling

allowDefaultProject

.ts

npm install -D jiti

[[mypy.overrides]]

ignore_missing_imports

pip install ruff

uv add ruff

Version: 4.0.0 Last Updated: 2026-03-18