Issue with tpl.js files that are copied over, running through prettier and failing on Heroku

Bug Report

Describe the bug

npx docz build fails on heroku, it works perfectly on our OSX machines.

It looks to me like the template files that are generated are breaking as they’re generated:

import React from 'react'
import { hot } from 'react-hot-loader'
import Theme from 'docz-theme-default'
import { imports } from './imports' import db from './db.json' 
const Root = () => (
  <theme db="{db}" imports="{imports}" hashrouter="{" false }   >
)
export default hot(module)(Root)

Once the broken files are copied over, prettier is failing to parse them.

✖  fatal     SyntaxError: Unexpected token, expected ";" (1:27)
> 1 | import React from 'react' import { hot } from 'react-hot-loader' import Theme from 'docz-theme-default' import { imports } from './imports' import db from './db.json'  const Root = () => (<theme db="{db}" imports="{imports}" hashrouter="{" false }   >) export default hot(module)(Root)
    |                           ^
    at t (/app/node_modules/docz-utils/node_modules/prettier/parser-babylon.js:1:326)
    at Object.d [as parse] (/app/node_modules/docz-utils/node_modules/prettier/parser-babylon.js:1:187968)
    at Object.parse$2 [as parse] (/app/node_modules/docz-utils/node_modules/prettier/index.js:7138:19)
    at coreFormat (/app/node_modules/docz-utils/node_modules/prettier/index.js:10398:23)
    at format (/app/node_modules/docz-utils/node_modules/prettier/index.js:10570:16)
    at formatWithCursor (/app/node_modules/docz-utils/node_modules/prettier/index.js:10582:12)
    at /app/node_modules/docz-utils/node_modules/prettier/index.js:34924:15
    at Object.format (/app/node_modules/docz-utils/node_modules/prettier/index.js:34943:12)
    at Promise (/app/node_modules/docz-utils/lib/index.js:1:4327)
    at new Promise (<anonymous>)
    at Object.format (/app/node_modules/docz-utils/lib/index.js:1:4292)
    at Promise (/app/node_modules/docz-core/dist/index.js:1:87660)
    at new Promise (<anonymous>)
    at touch (/app/node_modules/docz-core/dist/index.js:1:87581)
    at writeAppFiles (/app/node_modules/docz-core/dist/index.js:1:91416)
    at <anonymous>

I’ve created a repository with the failing build step if you deploy on Heroku here: https://github.com/shortlist-digital/tapestry-lite-docz

(I’ve since removed our internal library tapestry-lite from the heroku app, and docz build still fails.

Additional context/Screenshots Add any other context about the problem here. If applicable, add screenshots to help explain.

This is really strange, and only occurs on Heroku containers.

[jedrichards]

I get the exact same error when building on Netlify. I think I’ve tracked it down to when a NODE_ENV=production env var is present. In fact this fails the build locally too, as well as in Heroku/Netlify containers:

NODE_ENV=production yarn build:docz
✖  fatal     SyntaxError: Unexpected token, expected ";" (1:27)

Feels like a bug somewhere? Setting NODE_ENV to production is common practice when building on services like Heroku.

[jonsherrard]

Docz authors, thank you for the fantastic tool and all the work you’ve done on it.

I can’t believe it’s free!

When I find some time I’ll try and contribute a fix as a way of saying thanks.

@bingo4508 might even help too