@quasar/quasar-app-extension-typescript/index.js

/**
 * Quasar App Extension index/runner script
 * (runs on each dev/build)
 *
 * API: https://github.com/quasarframework/quasar/blob/master/app/lib/app-extension/IndexAPI.js
 */

module.exports = function(api, ctx) {
  api.chainWebpack((chain, invoke) => {

  if (api.prompts.webpack === 'vanilla') {
    chain.resolve.extensions.add(".ts").add('.tsx')
    chain.module
      .rule("typescript")
      .test(/\.tsx?$/)
      .use("typescript")
      .loader("ts-loader")
      .options({
        appendTsSuffixTo: [/\.vue$/],
        onlyCompileBundledFiles: true
      })

  } else if (api.prompts.webpack === 'plugin') {
    const ForkTsCheckerWebpackPlugin = require('fork-ts-checker-webpack-plugin')
    chain.resolve.extensions.add('.ts').add('.tsx')
    chain.module
      .rule('typescript')
      .test(/\.tsx?$/)
      .use('typescript')
      .loader('ts-loader')
      .options({
        appendTsSuffixTo: [/\.vue$/],
        // Type checking is handled by fork-ts-checker-webpack-plugin
        transpileOnly: true
      })
    chain.plugin('ts-checker').use(ForkTsCheckerWebpackPlugin, [{ vue: true }])
  }
  })
}