Parser parses JSX before customTransform function execution

[gornyyvladimir]

Hello! I have a project that uses React + Flow. Because I have Flow in project scanner shows Unable to parse Trans component from error. I have written this customTransform function to remove Flow types:

transform: function customTransform(file, enc, done) {
    const parser = this.parser;
    const content = fs.readFileSync(file.path, enc);
    const code = flowRemoveTypes(content)
    parser.parseTransFromString(code.toString());
    done();
  },

However, if you have extensions array in trans options, this code will run and crash your app: https://github.com/i18next/i18next-scanner/blob/b19aa7b1c8fb5587f65d9a568145676687a43f7f/src/index.js#L35

    trans: {
      component: 'Trans',
      i18nKey: 'i18nKey',
      defaultsKey: 'defaults',
      extensions: ['.js', '.jsx'], // <--- this line crash my app, if extensions not null
      fallbackKey: function(ns, value) {
        return value;
      },
      acorn: {
        ecmaVersion: 10, // defaults to 10
        sourceType: 'module', // defaults to 'module'
      },
    },

Because it tries to parse code before the transformation, and Flow types crash it.

If I change extensions to null and modify customTransform function it will run first, and parser in function (parser.parseTransFromString) will work with transformed code and all is ok. My final customTransform:

  transform: function customTransform(file, enc, done) {
    const parser = this.parser;
    const extname = path.extname(file.path);
    console.log(file.path, extname);
    const content = fs.readFileSync(file.path, enc);
    if (['.js', '.jsx'].includes(extname)) {
      const code = flowRemoveTypes(content)
      parser.parseTransFromString(code.toString());
    }
    done();
  },