libdenolint

Deno lint library binding for Node.js

Used in bundler plugins: rollup-plugin-denolint for Rollup, esbuild-plugin-denolint for esbuild, webpack-loader-denolint for Webpack.

This project started as fork of customised @node-rs/deno-lint, adding the flexibility of eslint:

• Scan specific directories with specific ignore patterns (631, 647)
• Scan directories configured by files.include (635, 645)
• Fix handling of the configuration files.exclude (635, 646)
• Support disabling rules in souces using eslint-disable (630, 642)
• Support including and excluding rules in the lint method (631, 643)
• Offer both synchronous and asynchronous methods (650)
• Allow specifying directories, files and patterns as input for checking
• Print warning messages in pretty or compact formats

Synopsis

Scan sources in the current directory:

import { denolint } from 'libdenolint'

process.exitCode = await denolint() ? 0 : 1

Check one source file:

import { readFile } from 'fs/promises'
import { lint } from 'libdenolint'

const filepath = 'src/index.js'
const source = await readFile(filepath)

try {
  const warnings = await lint(filepath, source)
  for (const warning of warnings) console.warn(warning)
} catch ({ message }) {
  console.error(message)
}

Usage of denolint

import { denolint, denolintSync } from 'libdenolint'

interface DenoLintOptions {
  scanDirs?: string[],
  ignorePatterns?: string[]
}

function denolint(
  projectDir?: string, configPath?: string,
  options?: DenoLintOptions, signal?: AbortSignal
): Promise<boolean>

function denolintSync(
  projectDir?: string, configPath?: string, options?: DenoLintOptions
): boolean

The project directory will be scanned if no directory is specified either on the command line or in the config file. Directories from scanDirs take precedence over the directories in the config file.

Returns true if all files are valid, otherwise false.

projectDir

• Type: String
• Default: current directory

Root directory of the project, which contains files .denolintignore or .eslintignore. Defaults to the current directory.

configPath

• Type: String
• Default: '.denolint.json'

Config path relative to the lint path. If not provided, a .denolint.json in the project directory will be tried to load. If an empty string is specified explicitly, it will disable searching for the default config file.

Config file must be a JSON file:

Example:

{
  "files": {
    "include": ["src", "test"],
    "exclude": ["examples"]
  },
  "rules": {
    "tags": ["recommended"],
    "exclude": [
      "no-explicit-any",
      "ban-unknown-rule-code",
      "no-window-prefix",
      "no-empty-interface",
      "ban-types",
      "ban-untagged-todo",
      "no-unused-vars",
      "ban-ts-comment",
      "no-case-declarations",
      "no-this-alias"
    ]
  }
}

Check out deno_lint rules for all rules.

scanDirs

• Type: String[]
• Default: []

Directories to scan for sources. The project directory will be scanned if none specified.

ignorePatterns

• Type: String[]
• Default: []

File patterns to ignore when the source directories are scanned. I applies only to directories specified on the command line; not to the directories specified by files.include from the config file.

dryRun

• Type: Boolean
• Default: false

Only lists the files names, which would be processed, without checking their syntax. It can be used to learn what files will be processed.

signal

• Type: AbortSignal
• Default: undefined

A signal from an AbortController to abort the operation. Optional.

Usage of lint

import { lint, lintSync } from 'libdenolint'

function lint(
  fileName: string, sourceCode: string | Buffer,
  allRules?: boolean, excludeRules?: string[], includeRules?: string[],
  signal?: AbortSignal
): Promise<Array<string>>

function lintSync(
  fileName: string, sourceCode: string | Buffer,
  allRules?: boolean, excludeRules?: string[], includeRules?: string[]
): Array<string>

Returns an empty array if the files is valid, otherwise the array will contain printable warnings about the problems found. May throw an error in case of a fatal parser failure.

fileName

• Type: String

The name of the source file for diagnostic messages.

sourceCode

• Type: String | Buffer

The contents of the source file to be checked.

allRules

• Type: Boolean
• Default: false

Whether to enable all rules. If false, denolint will enable only the recommend rules.

excludeRules

• Type: String[]
• Default: []

Rules to exclude from all or recommended ones chosen by enableAllRules.

includeRules

• Type: String[]
• Default: []

Rules to include in addition to the recommended ones chosen by enableAllRules set to false.

signal

• Type: AbortSignal
• Default: undefined

A signal from an AbortController to abort the operation. Optional.

Migration from @node-rs/deno-lint

Methods denolint and lint are synchronous. If you want to retain the synchronous behaviour, call the methods with the Sync suffix:

- denolint(process.cwd(), '.denolint.json')
+ denolintSync(process.cwd(), '.denolint.json')

- lint(fileName, fileContents)
+ lintSync(fileName, fileContents)

Methods denolint and denolintSync return boolean (or a Promise to a boolean) with the result of the syntax check. The value true means success, the value false means a failure. Pay attention, the boolean retuurned by the method denolint from @node-rs/deno-lint has the meaning the other way round!

Troubleshooting

If the installation fails, set the environment variable LIBDENOLINT_DEBUG to true and watch the debugging output on the console.

Support matrix

| Platform | node14 | node16 | node18 | | ---------------- | ------ | ------ | ------ | | Windows x64 | ✓ | ✓ | ✓ | | Windows x32 | ✓ | ✓ | ✓ | | Windows arm64 | ✓ | ✓ | ✓ | | MacOS x64 | ✓ | ✓ | ✓ | | MacOS arm64 | ✓ | ✓ | ✓ | | Linux x64 gnu | ✓ | ✓ | ✓ | | Linux x64 musl | ✓ | ✓ | ✓ | | Linux arm gnu | ✓ | ✓ | ✓ | | Linux arm64 gnu | ✓ | ✓ | ✓ | | Linux arm64 musl | × | × | × | | Android arm64 | × | × | × | | Android armv7 | × | × | × | | FreeBSD x64 | ✓ | ✓ | ✓ |

Contributing

In lieu of a formal styleguide, take care to maintain the existing coding style. Add unit tests for any new or changed functionality. Lint and test your code.

License

Copyright (c) 2020-2022 LongYinan Copyright (c) 2023 Ferdinand Prantl

Licensed under the MIT license.