index.cjs

'use strict'

/**
 * @import {TsConfigSourceFile} from 'typescript'
 * @import {Plugin} from 'unified'
 */

const {pathToFileURL} = require('node:url')
const {
  createMdxLanguagePlugin,
  resolveRemarkPlugins
} = require('@mdx-js/language-service')
const {
  createAsyncLanguageServicePlugin
} = require('@volar/typescript/lib/quickstart/createAsyncLanguageServicePlugin.js')
const {loadPlugin} = require('load-plugin')
const {default: remarkFrontmatter} = require('remark-frontmatter')
const {default: remarkGfm} = require('remark-gfm')

const plugin = createAsyncLanguageServicePlugin(
  ['.mdx'],
  2 /* JSX */,
  async (ts, info) => {
    if (info.project.projectKind !== ts.server.ProjectKind.Configured) {
      return {
        languagePlugins: [
          createMdxLanguagePlugin([
            [remarkFrontmatter, ['toml', 'yaml']],
            remarkGfm
          ])
        ]
      }
    }

    const cwd = info.project.getCurrentDirectory()
    const configFile = /** @type {TsConfigSourceFile} */ (
      info.project.getCompilerOptions().configFile
    )

    const commandLine = ts.parseJsonSourceFileConfigFileContent(
      configFile,
      ts.sys,
      cwd,
      undefined,
      configFile.fileName
    )

    const plugins = await resolveRemarkPlugins(
      commandLine.raw?.mdx,
      (name) =>
        /** @type {Promise<Plugin>} */ (
          loadPlugin(name, {prefix: 'remark', from: pathToFileURL(cwd) + '/'})
        )
    )

    return {
      languagePlugins: [
        createMdxLanguagePlugin(
          plugins || [[remarkFrontmatter, ['toml', 'yaml']], remarkGfm],
          Boolean(commandLine.raw?.mdx?.checkMdx),
          commandLine.options.jsxImportSource
        )
      ]
    }
  }
)

module.exports = plugin