Error when opening TSX file: Cannot use JSX unless '--jsx' flag is provided

[josh-endries]

• VSCode Version: 1.7.1
• OS Version: Windows 8.1

Steps to Reproduce:

1. Open a TSX file.

This seems kind of ridiculous, given that VSC comes with TS built in. It doesn't know what to do with TSX files? It should automatically add the flag to tsc if it's processing a TSX file.

[zeh]

I had this intermittently over the past few days (Windows 10 though).

I think I solved it by adding...

"include": [
  "./src/ts/**/*"
]

...to tsconfig.json. Your .ts locations may vary.

[josh-endries]

Well I worked around it by adding "jsx": "react" to tsconfig.json, as far as I can tell, but that is missing the point.

When you open a TSX file (not a directory), you don't have a tsconfig.json file.

[mjbvz]

Ok, I believe the expected behavior would be:

• If a jsconfig.json or tsconfig.json exists, do nothing. You need to add a "jsx" setting in the config file in that case.
• For implicit projects, either opening a file directly or opening a directory without a *config.json, assume "jsx": "preserve" for tooling. You would still have to pass a "jsx" setting to actually compile any typescript code in that case, but our tools would work better for most scenarios. If you want to opt into using "jsx": "react", you would need to create a *config.json project file.

Does that sound correct?

[zeh]

@mjbvz In my case, the problem was there even though I did have "jsx": "react" inside tsconfig.json already. It was only adding the include parameter that fixed it, I believe*.

(* I say "I believe" because it was really intermittent, so I'm not 100% sure what solved it. It's gone now though)

[scriptmaster]

Setting tsconfig.json jsx: "preserve" or "react" corrected vscode --jsx defect.

{
  "compilerOptions": {

    "jsx": "preserve",                     /* Specify JSX code generation: 'preserve', 'react-native', or 'react'. */

    }
}

Tip: tsconfig init gives a big list of options where you can easily spot jsx and uncomment.