Error: `Cannot read property 'length' of undefined` with `tsx` file and `jsx: "preserve"` setting

When processing a tsx source file I get an error, however if I manually compile with tsc I don’t get an error.

Environment:

Windows: 10 NodeJS: 7.10 NPM: 5.0.4

Project structure

./
  tsconfig.json
  package.json
  rollup.config.js
  src/
    main.ts
    jsx-utils.ts
    components/
      topbar.tsx

Here’s a gist with the relevant files in the above structure.

Error:

$ npm run build

> testtsx@1.0.0 build C:\repos\testtsx
> rollup -c

🚨   Cannot read property 'length' of undefined
src\components\topbar.tsx

I was using the older typescript plugin, rollup-plugin-typescript and just require’d in my local typescript, and that worked, but found that this existed so I gave it a whirl.

Let me know if I have something setup wrong! <3<3 Thanks for reading.

[ezolenko]

@lastmjs this looks like a different error, could you open a new issue and fill in all the info? (and add more details on experimentalPreserveModules option)

[ghost]

Thanks for pushing that out! I upgraded to this plugin over the older one, yay!

The Dream

For future reference; tsconfig now has an option "jsxFactory": "h", - it seems to eliminate the need for jsx/buble/babel plugin altogether. And since typescript also has a concatenation option with outFile - I’ll be experimenting with removing rollup as well. (I think I needed to ditch the jsx: preserve and use react target, but it’s not really react since I can specify the factory… But it does what I want!)

I’m aiming for a zero dependency, minimal devDependency jsx workflow:

package.json

"scripts": {
  "build": "tsc",
  "start": "http-server -a localhost",
  "dev": "run-p \"build -- -w\" start"
},
...
"dependencies": {},
"devDependencies": {
  "typescript": "2.4.1",
  "npm-run-all": "4.0.2",
  "http-server": "0.10.0"
}
...

Living the dream! Perfect for quickly componentizing static sites. If needed, I can add a small data binding implementation, then I can have something pretty nifty.

I’m just experimenting in a quick personal project with a bare metal approach. No jquery, no framework, just lots of ~stolen~borrowed ideas xD.