fix: disable JSX parsing for TypeScript files

Author: Stanzilla

packages/react-docgen/src/__tests__/babel8-test.ts

@@ -36,3 +36,20 @@ test('parses TypeScript function props with Babel 8', () => {
     },
   });
 });
+
+test('parses generic arrow functions in TypeScript files with Babel 8', () => {
+  const result = parse(
+    `import React from 'react';
+
+    export const mockDomain = <Entity>(
+      entities: Record<string, Entity> = {},
+    ) => ({ entities });
+
+    export function Button() {
+      return React.createElement('button');
+    }`,
+    { filename: 'store.ts' },
+  );
+
+  expect(result).toHaveLength(1);
+});

packages/react-docgen/src/babelParser.ts

@@ -16,11 +16,11 @@ const IS_BABEL_8 = Number.parseInt(version, 10) >= 8;
 function getDefaultPlugins(
   options: TransformOptions,
 ): NonNullable<ParserOptions['plugins']> {
+  const extension = options.filename ? extname(options.filename) : '';
+  const isTypeScript = TYPESCRIPT_EXTS.has(extension);
   const plugins: NonNullable<ParserOptions['plugins']> = [
-    'jsx',
-    options.filename && TYPESCRIPT_EXTS.has(extname(options.filename))
-      ? 'typescript'
-      : 'flow',
+    ...(isTypeScript && extension !== '.tsx' ? [] : ['jsx' as const]),
+    isTypeScript ? 'typescript' : 'flow',
     'asyncDoExpressions',
   ];