Fix injecting providers for jsx in esm, expressions

Closes GH-2449.
Related-to: facebook/docusaurus#9905.

Author: wooorm

packages/mdx/lib/plugin/remark-mark-and-unravel.js

@@ -4,6 +4,7 @@
  */
 
 import {collapseWhiteSpace} from 'collapse-white-space'
+import {walk} from 'estree-walker'
 import {visit} from 'unist-util-visit'
 
 /**
@@ -92,6 +93,23 @@ export function remarkMarkAndUnravel() {
         const data = node.data || (node.data = {})
         data._mdxExplicitJsx = true
       }
+
+      if (
+        (node.type === 'mdxFlowExpression' ||
+          node.type === 'mdxTextExpression' ||
+          node.type === 'mdxjsEsm') &&
+        node.data &&
+        node.data.estree
+      ) {
+        walk(node.data.estree, {
+          enter(node) {
+            if (node.type === 'JSXElement') {
+              const data = node.data || (node.data = {})
+              data._mdxExplicitJsx = true
+            }
+          }
+        })
+      }
     })
   }
 }

packages/mdx/test/compile.js

@@ -1246,11 +1246,7 @@ test('@mdx-js/mdx: compile (JSX)', async function (t) {
           '/*@jsxRuntime automatic*/',
           '/*@jsxImportSource react*/',
           'function _createMdxContent(props) {',
-          '  const _components = {',
-          '    "a-b": "a-b",',
-          '    ...props.components',
-          '  }, _component0 = _components["a-b"];',
-          '  return <>{<_component0></_component0>}</>;',
+          '  return <>{<a-b></a-b>}</>;',
           '}',
           'export default function MDXContent(props = {}) {',
           '  const {wrapper: MDXLayout} = props.components || ({});',
@@ -1351,6 +1347,97 @@ test('@mdx-js/mdx: compile (JSX)', async function (t) {
     }
   )
 
+  await t.test(
+    'should not inject a provider for JSX in ESM',
+    async function () {
+      assert.equal(
+        String(
+          await compile(
+            'export function A() { return <span /> }\n\nexport class B { render() { return <div /> } }',
+            {providerImportSource: '@mdx-js/react'}
+          )
+        ),
+        [
+          'import {Fragment as _Fragment, jsx as _jsx} from "react/jsx-runtime";',
+          'import {useMDXComponents as _provideComponents} from "@mdx-js/react";',
+          'export function A() {',
+          '  return _jsx("span", {});',
+          '}',
+          'export class B {',
+          '  render() {',
+          '    return _jsx("div", {});',
+          '  }',
+          '}',
+          'function _createMdxContent(props) {',
+          '  return _jsx(_Fragment, {});',
+          '}',
+          'export default function MDXContent(props = {}) {',
+          '  const {wrapper: MDXLayout} = {',
+          '    ..._provideComponents(),',
+          '    ...props.components',
+          '  };',
+          '  return MDXLayout ? _jsx(MDXLayout, {',
+          '    ...props,',
+          '    children: _jsx(_createMdxContent, {',
+          '      ...props',
+          '    })',
+          '  }) : _createMdxContent(props);',
+          '}',
+          ''
+        ].join('\n')
+      )
+    }
+  )
+
+  await t.test(
+    'should not inject a provider for JSX in expressions',
+    async function () {
+      console.log(
+        String(
+          await compile('{ <span /> }\n\nAnd also { <div /> }.', {
+            providerImportSource: '@mdx-js/react'
+          })
+        )
+      )
+      assert.equal(
+        String(
+          await compile('{ <span /> }\n\nAnd also { <div /> }.', {
+            providerImportSource: '@mdx-js/react'
+          })
+        ),
+        [
+          'import {Fragment as _Fragment, jsx as _jsx, jsxs as _jsxs} from "react/jsx-runtime";',
+          'import {useMDXComponents as _provideComponents} from "@mdx-js/react";',
+          'function _createMdxContent(props) {',
+          '  const _components = {',
+          '    p: "p",',
+          '    ..._provideComponents(),',
+          '    ...props.components',
+          '  };',
+          '  return _jsxs(_Fragment, {',
+          '    children: [_jsx("span", {}), "\\n", _jsxs(_components.p, {',
+          '      children: ["And also ", _jsx("div", {}), "."]',
+          '    })]',
+          '  });',
+          '}',
+          'export default function MDXContent(props = {}) {',
+          '  const {wrapper: MDXLayout} = {',
+          '    ..._provideComponents(),',
+          '    ...props.components',
+          '  };',
+          '  return MDXLayout ? _jsx(MDXLayout, {',
+          '    ...props,',
+          '    children: _jsx(_createMdxContent, {',
+          '      ...props',
+          '    })',
+          '  }) : _createMdxContent(props);',
+          '}',
+          ''
+        ].join('\n')
+      )
+    }
+  )
+
   await t.test(
     'should serialize double quotes in attribute values',
     async function () {