- name
- swc-config-validator
- description
- Validate SWC config files (.swcrc, package.json#swc) for parser settings, transform conflicts, module type issues, and best practices. Use when validating SWC transpiler configs, auditing Next.js/Turbopack build setups, or linting swc config files.
SWC Config Validator
Validate .swcrc and package.json#swc for parser errors, invalid targets, transform conflicts, module type issues, minification problems, and best practices. Supports text, JSON, and summary output formats with CI-friendly exit codes.
Commands
# Full validation (all 22+ rules)
python3 scripts/swc_config_validator.py validate .swcrc
# Quick syntax/structure check only
python3 scripts/swc_config_validator.py check .swcrc
# Explain config in human-readable form
python3 scripts/swc_config_validator.py explain .swcrc
# Suggest improvements
python3 scripts/swc_config_validator.py suggest .swcrc
# JSON output (CI-friendly)
python3 scripts/swc_config_validator.py validate .swcrc --format json
# Summary only (pass/fail + counts)
python3 scripts/swc_config_validator.py validate .swcrc --format summary
# Strict mode (warnings become errors)
python3 scripts/swc_config_validator.py validate .swcrc --strict
# Validate from package.json#swc
python3 scripts/swc_config_validator.py validate package.jsonRules (22+)
| # | Category | Severity | Rule |
|---|---|---|---|
| S1 | Structure | Error | File not found or unreadable |
| S2 | Structure | Error | Empty config |
| S3 | Structure | Error | Invalid JSON syntax |
| S4 | Structure | Warning | Unknown top-level keys |
| S5 | Structure | Warning | Missing jsc key (most configs need it) |
| J1 | JSC Config | Error | Invalid parser syntax (must be ecmascript or typescript) |
| J2 | JSC Config | Warning | JSX enabled in parser without React transform |
| J3 | JSC Config | Warning | Deprecated loose mode in jsc.transform |
| J4 | JSC Config | Warning | Missing target (no compilation target specified) |
| J5 | JSC Config | Error | Invalid target value (not es3/es5/es2015-es2024/esnext) |
| M1 | Modules | Error | Unknown module type |
| M2 | Modules | Warning | isModule: false with ESM module type |
| M3 | Modules | Warning | CommonJS module with ESM-only parser features |
| T1 | Transform | Error | React transform without parser.jsx enabled |
| T2 | Transform | Warning | Legacy decorators without decoratorsBeforeExport |
| T3 | Transform | Warning | Conflicting useDefineForClassFields with TypeScript |
| T4 | Transform | Warning | Deprecated constModules in jsc.experimental |
| N1 | Minification | Warning | Minification enabled with compress: false |
| N2 | Minification | Warning | Mangle enabled without compress |
| N3 | Minification | Warning | Drop console in development config |
| B1 | Best Practices | Warning | sourceMaps not configured |
| B2 | Best Practices | Info | No env config for different environments |
Output Formats
text(default): Human-readable with severity iconsjson: Machine-parseable JSON array of findingssummary: Pass/fail with error/warning counts
Exit Codes
0: No errors (warnings/info only or clean)1: One or more errors found2: File not found or invalid input
Requirements
- Python 3.8+
- No external dependencies (pure stdlib)
Supported Targets
es3, es5, es2015 through es2024, esnext
Supported Module Types
es6, commonjs, umd, amd, nodenext, systemjs
Valid Top-Level Keys
$schema, jsc, module, minify, env, isModule, sourceMaps, inlineSourcesContent, emitSourceMapColumns, inputSourceMap, test, exclude, filename