resolvePath()

in babel.config.js [60:70]


          resolvePath(sourcePath, currentFile, opts) {
            if (
              currentFile.startsWith(packagePath) &&
              currentFile.endsWith('.ts') &&
              sourcePath.startsWith('.') &&
              sourcePath.endsWith('.js')
            ) {
              return sourcePath.replace(/\.js$/, '.ts');
            }
            return resolvePath(sourcePath, currentFile, opts);
          },