@bfra.me/eslint-config/src/configs/prettier.ts

Shared ESLint configuration for bfra.me

import type {Config} from '../config'
import type {Flatten, OptionsIsInEditor, OptionsOverrides} from '../options'
import process from 'node:process'
import {GLOB_EXT_IN_MARKDOWN_FILES, GLOB_MARKDOWN_FILES, GLOB_TOML_FILES} from '../globs'
import {requireOf} from '../require-of'
import {interopDefault} from '../utils'
import {fallback} from './fallback'

function getConfigRules(configs: unknown): OptionsOverrides['overrides'] | undefined {
  if (Array.isArray(configs)) {
    const configWithRules = [...(configs as unknown[])]
      .reverse()
      .find(
        (config): config is Config =>
          typeof config === 'object' && config !== null && 'rules' in config,
      )

    return configWithRules?.rules
  }

  if (typeof configs === 'object' && configs !== null && 'rules' in configs) {
    return (configs as Config).rules
  }

  return undefined
}

/**
 * Represents the options for the ESLint Prettier configuration.
 */
export type PrettierOptions = Flatten<OptionsIsInEditor & OptionsOverrides>

/**
 * Generates an ESLint configuration for Prettier.
 * @param options - The options for the Prettier configuration.
 * @returns An array of ESLint configurations.
 */
export async function prettier(options: PrettierOptions = {}): Promise<Config[]> {
  const {isInEditor, overrides} = options
  return requireOf(
    ['eslint-config-prettier', 'eslint-plugin-prettier', 'prettier'],
    async () => {
      // Disable deprecated rules before importing eslint-config-prettier
      process.env.ESLINT_CONFIG_PRETTIER_NO_DEPRECATED ??= 'true'
      const [configPrettier, pluginPrettier, pluginJsonc, pluginYaml] = await Promise.all([
        interopDefault(import('eslint-config-prettier')),
        interopDefault(import('eslint-plugin-prettier')),
        interopDefault(import('eslint-plugin-jsonc')).catch(() => undefined),
        interopDefault(import('eslint-plugin-yml')).catch(() => undefined),
      ])
      const jsoncPrettierRules = getConfigRules(pluginJsonc?.configs.prettier)
      const yamlPrettierRules = getConfigRules(pluginYaml?.configs.prettier)

      return [
        {
          name: '@bfra.me/prettier',
          plugins: {
            prettier: pluginPrettier,
          },
          rules: {
            'prettier/prettier': isInEditor ? 'warn' : 'error',

            ...configPrettier.rules,

            ...(jsoncPrettierRules ?? {}),

            'toml/array-bracket-newline': 'off',
            'toml/array-bracket-spacing': 'off',
            'toml/array-element-newline': 'off',
            'toml/indent': 'off',
            'toml/inline-table-curly-spacing': 'off',
            'toml/key-spacing': 'off',
            'toml/table-bracket-spacing': 'off',

            ...(yamlPrettierRules ?? {}),

            ...overrides,
          },
        },
        {
          name: '@bfra.me/prettier/markdown',
          files: GLOB_MARKDOWN_FILES,
          rules: {
            'prettier/prettier': [
              'error',
              {
                embeddedLanguageFormatting: 'off',
                parser: 'markdown',
              },
            ],
          },
        },
        {
          name: '@bfra.me/prettier/toml',
          files: GLOB_TOML_FILES,
          rules: {
            // TODO: Detect if the TOML plugin for Prettier is installed
            // and if so, use the Prettier rules
            'prettier/prettier': 'off',
          },
        },
        {
          name: '@bfra.me/prettier/overrides',
          files: GLOB_EXT_IN_MARKDOWN_FILES,
          rules: {
            'prettier/prettier': 'off',
          },
        },
      ] as Config[]
    },
    fallback,
  )
}