adapter-prettier

Runs Prettier via the CLI (prettier --check / prettier --write) and generates a .prettierrc file.

Package: @retemper/lodestar-adapter-prettier

Managed file: .prettierrc

Config Options

Option	Type	Description
printWidth	number	Line width (default: 80)
tabWidth	number	Spaces per indentation level (default: 2)
useTabs	boolean	Use tabs instead of spaces
semi	boolean	Use semicolons
singleQuote	boolean	Use single quotes
trailingComma	'all' | 'es5' | 'none'	Trailing commas
bracketSpacing	boolean	Spaces inside object braces
arrowParens	'always' | 'avoid'	Parens for single arrow function args
endOfLine	'lf' | 'crlf' | 'cr' | 'auto'	Line ending style
ignore	string[]	Glob patterns to ignore
bin	string	Binary name or path (default: "prettier")
include	string[]	File patterns to check

Example

import { prettierAdapter } from '@retemper/lodestar-adapter-prettier';

prettierAdapter({
  singleQuote: true,
  trailingComma: 'all',
  semi: true,
  tabWidth: 2,
  printWidth: 100,
});

How verifySetup Works

1. Checks that .prettierrc exists in rootDir.
2. Reads the file content and compares it against the JSON that lodestar config produces.
3. Returns a missing violation if the file does not exist.
4. Returns a drift violation (with a diff of expected vs actual) if the content does not match.
5. Returns no violations if .prettierrc matches.

Drift means the .prettierrc file was manually edited or overwritten by another tool, so it no longer reflects the lodestar config. Running lodestar check --fix regenerates the file to resolve the violation.

How check Works

The adapter runs Prettier via the CLI:

1. Executes prettier --check with the configured file patterns (or defaults to common file types).
2. Parses the output to identify files that are not formatted correctly.
3. Each unformatted file is reported as a Violation with rule ID prettier/format.

All formatting violations are reported with severity 'warn'.

Auto-fix

The adapter implements fix(), which runs prettier --write on the configured file patterns. Running lodestar check --fix invokes this to auto-format all files in place.