- name
- rollup-config-validator
- description
- Validate Rollup config files (rollup.config.js/mjs/ts) for output format conflicts, plugin ordering issues, deprecated options, and best practices. Use when validating Rollup bundler configs, auditing build pipelines, migrating Rollup versions, or linting rollup config files.
Rollup Config Validator
Validate Rollup config files (exported JSON or parsed config objects) for output format conflicts, external/bundle mismatches, plugin ordering issues, deprecated options, treeshake settings, and best practices. Supports text, JSON, and summary output formats with CI-friendly exit codes.
Commands
# Full validation (all 22+ rules)
python3 scripts/rollup_config_validator.py validate rollup.config.json
# Quick syntax-only check (structure rules only)
python3 scripts/rollup_config_validator.py check rollup.config.json
# Explain config in human-readable form
python3 scripts/rollup_config_validator.py explain rollup.config.json
# Suggest improvements
python3 scripts/rollup_config_validator.py suggest rollup.config.json
# JSON output (CI-friendly)
python3 scripts/rollup_config_validator.py validate rollup.config.json --format json
# Summary only (pass/fail + counts)
python3 scripts/rollup_config_validator.py validate rollup.config.json --format summary
# Strict mode (warnings become errors)
python3 scripts/rollup_config_validator.py validate rollup.config.json --strictInput Format
Since Rollup configs are typically JavaScript, this tool validates JSON representations of Rollup config objects. Export your config as JSON or use a wrapper:
# Extract config as JSON from rollup.config.js
node -e "const c = require('./rollup.config.js'); console.log(JSON.stringify(c, null, 2))" > rollup.config.json
python3 scripts/rollup_config_validator.py validate rollup.config.jsonOr validate directly from a JSON config file.
Rules (22+)
| # | Category | Severity | Rule |
|---|---|---|---|
| S1 | Structure | Error | File not found or unreadable |
| S2 | Structure | Error | Empty config or no content |
| S3 | Structure | Warning | Unknown top-level config keys |
| S4 | Structure | Error | Invalid JSON syntax |
| S5 | Structure | Error | Missing input entry point |
| O1 | Output | Error | Missing output configuration |
| O2 | Output | Warning | Missing output.format (defaults to 'es') |
| O3 | Output | Warning | output.file and output.dir both specified |
| O4 | Output | Warning | format: 'iife' or 'umd' without output.name |
| O5 | Output | Warning | Multiple outputs with same format and no distinct file/dir |
| O6 | Output | Warning | output.sourcemap: true without sourcemapExcludeSources consideration |
| E1 | External | Warning | Bare module in external should match import pattern |
| E2 | External | Warning | Regex pattern in external (fragile) |
| E3 | External | Warning | Node built-in not in external (path, fs, etc.) |
| P1 | Plugins | Warning | Plugin ordering: resolve before commonjs |
| P2 | Plugins | Warning | commonjs plugin without @rollup/plugin-node-resolve |
| P3 | Plugins | Warning | json plugin missing (importing .json files) |
| P4 | Plugins | Warning | Deprecated plugin (rollup-plugin-* → @rollup/plugin-*) |
| T1 | Treeshake | Warning | treeshake: false disables dead code elimination |
| T2 | Treeshake | Warning | moduleSideEffects: false may break libraries |
| B1 | Best Practices | Warning | Missing preserveEntrySignatures for library builds |
| B2 | Best Practices | Warning | Large number of manual chunks without shared dependencies |
| B3 | Best Practices | Warning | watch mode config without clearScreen setting |
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 only or clean)1: One or more errors found2: File not found or invalid input
Requirements
- Python 3.8+
- No external dependencies (pure stdlib)