TypeScript files are not minified during build (gatsby-plugin-typescript)

When running npm run build all typescript files are converted into non-minified javascript files in the public folder.

Example based on Gatsby default starter: https://github.com/tomazy/gatsby-site-typescript-issue (see the public folder)

Environment:

• gatsby@1.9.119
• node v8.2.1
• macOS Sierra 10.12.6

gatsby-config.js

module.exports = {
  siteMetadata: {
    title: `Gatsby Default Starter`,
  },
  plugins: [
    `gatsby-plugin-react-helmet`,
    `gatsby-plugin-typescript`,
  ],

package.json

{
  "name": "gatsby-starter-default",
  "description": "Gatsby default starter",
  "version": "1.0.0",
  "author": "Kyle Mathews <[e-mail]>",
  "dependencies": {
    "@types/node": "8.0.53",
    "@types/prop-types": "15.5.2",
    "@types/react": "16.0.25",
    "@types/react-dom": "16.0.3",
    "@types/react-helmet": "5.0.3",
    "@types/react-router-dom": "4.2.2",
    "gatsby": "^1.9.119",
    "gatsby-link": "^1.6.28",
    "gatsby-plugin-react-helmet": "^1.0.8",
    "gatsby-plugin-typescript": "1.4.10"
  },
  "keywords": [
    "gatsby"
  ],
  "license": "MIT",
  "main": "n/a",
  "scripts": {
    "build": "gatsby build",
    "develop": "gatsby develop",
    "format": "prettier --trailing-comma es5 --no-semi --single-quote --write \"src/**/*.js\"",
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "devDependencies": {
    "prettier": "^1.8.2"
  }
}

[tomazy]

My fault - I updated gatsby but not gatsby-plugin-typescript.

Confirming that it works as expected with

• gatsby 1.9.175
• gatsby-plugin-typescript 1.4.15

[jurosh]

Hm… it might be issue with tsconfig.

For me it’s working fine with:

"module": "commonjs",
"target": "esnext",