Mobx-state-tree: types.identifier is not a function with Babel 7

[qaiser110]

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I'm trying to upgrade Next.js to version 7, but MST is causing an issue. I'm using custom-server-and-routing When I run npm run build, the builds successfully, I get the following error:

TypeError: mobx_state_tree__WEBPACK_IMPORTED_MODULE_1__.types.identifier is not a function
    at Object.<anonymous> (/Users/abbasq6v/Documents/dev/react/antd/heroku-nextjs/.next/server/static/MPv274FiSI3tRFordioX_/pages/quotes.js:1215:61)
    at __webpack_require__ (/Users/abbasq6v/Documents/dev/react/antd/heroku-nextjs/.next/server/static/MPv274FiSI3tRFordioX_/pages/quotes.js:23:31)
    at Object.<anonymous> (/Users/abbasq6v/Documents/dev/react/antd/heroku-nextjs/.next/server/static/MPv274FiSI3tRFordioX_/pages/quotes.js:3114:18)
    at __webpack_require__ (/Users/abbasq6v/Documents/dev/react/antd/heroku-nextjs/.next/server/static/MPv274FiSI3tRFordioX_/pages/quotes.js:23:31)
    at Module.<anonymous> (/Users/abbasq6v/Documents/dev/react/antd/heroku-nextjs/.next/server/static/MPv274FiSI3tRFordioX_/pages/quotes.js:8729:19)
    at __webpack_require__ (/Users/abbasq6v/Documents/dev/react/antd/heroku-nextjs/.next/server/static/MPv274FiSI3tRFordioX_/pages/quotes.js:23:31)
    at Object.<anonymous> (/Users/abbasq6v/Documents/dev/react/antd/heroku-nextjs/.next/server/static/MPv274FiSI3tRFordioX_/pages/quotes.js:8691:18)
    at __webpack_require__ (/Users/abbasq6v/Documents/dev/react/antd/heroku-nextjs/.next/server/static/MPv274FiSI3tRFordioX_/pages/quotes.js:23:31)
    at /Users/abbasq6v/Documents/dev/react/antd/heroku-nextjs/.next/server/static/MPv274FiSI3tRFordioX_/pages/quotes.js:91:18
    at Object.<anonymous> (/Users/abbasq6v/Documents/dev/react/antd/heroku-nextjs/.next/server/static/MPv274FiSI3tRFordioX_/pages/quotes.js:94:10)

This is what my .babelrc looks like:

{
      "presets": [
          "@babel/preset-env",
          "next/babel"
      ],
      "plugins": [
          "@babel/plugin-transform-object-assign",
          ["@babel/plugin-proposal-decorators", { "legacy": true }],
          ["@babel/plugin-proposal-class-properties", { "loose": true }]
      ]
}

I tried installing and running in sandbox, but there are no issues there, which makes me wonder if I'm missing something in my babel config.

Any help would be appreciated

[xaviergonz]

use types.identifier as a constant rather than types.identifier() as a function.
it works because it changed in MST 3 and the sandbox uses v2 by default

[qaiser110]

It works now. I had to change these few things to upgrade to MST 3:

• t.identifier() to t.identifier
• t.identifier(t.number) to t.identifierNumber
• t.maybe() to t.maybeNull()

and it all started working. Thanks @xaviergonz