preset-typescript should default to .ts and .tsx

Bug report

1. I put typescript and javascript files side by side and setup .babelrc config:

{
  "presets": [
    ["@babel/preset-env", {
      "targets": { "electron": "3.0" }
    }],
    "@babel/preset-react",
    ["@babel/preset-typescript", {
      "isTSX": true
    }],
    "@babel/preset-flow"
  ],
  "plugins": [
    "@babel/plugin-proposal-class-properties"
  ]
}

$ babel src/ --copy-files --out-dir build --extensions .ts,.tsx,.js
Successfully compiled 80 files with Babel.

Question

But is there any way to fix the preset-typescript to actually be conscious of file extensions? If Babel parses *.js only by default, is there any way for typescript preset to tell it to pick up .tsx and .ts too? I don’t really want to pass extensions all over my scripts. I believe the defaults should be sane enough.

Also, just tried to compile JSX in .tsx file and it seems to work. But what’s isTSX option is used for then?

isTSX Forcibly enables jsx parsing. Otherwise angle brackets will be treated as typescript’s legacy type assertion var foo = <string>bar;

The part about angle brackets does not make sense. It seems that JSX tags are properly compiled to React.createElement.

[pronebird]

@loganfsmyth great thanks! I had impression that isTSX is the only way to enable TSX support. But again, doing a practical test, it all seems to work.

Is there any plan to make preset-typescript automatically add .ts and .tsx extensions for parsing by babel? Because I think currently it doesn’t work without --extensions .ts,.tsx.

[loganfsmyth]

But is there any way to fix the preset-typescript to actually be conscious of file extensions?

I think there is some confusion here. That is the default behavior and it sounds like you don’t actually want to set isTSX in the first place. Setting isTSX: true overrides the default and forces it to treat all files as TSX, and for it to do that, you need to set allExtensions.

But what’s isTSX option is used for then?

Assuming you’ve set allExtensions to stop it from auto-deciding based on file extensions, isTSX toggles whether it should treat all files as .ts or .tsx.

It sounds like you want

    ["@babel/preset-env", {
      "targets": { "electron": "3.0" }
    }],
    "@babel/preset-react",
    "@babel/preset-typescript",
    "@babel/preset-flow"