From d54312bf276e492d0680d9449a66f527e9f50c51 Mon Sep 17 00:00:00 2001
From: Nathan Clevenger <nateclev@gmail.com>
Date: Wed, 11 Jun 2025 07:58:56 -0500
Subject: [PATCH] test(mdxld): compile render with real mdx

---
 packages/mdxld/src/render.test.ts | 139 +++++++++---------------------
 packages/mdxld/src/render.ts      |  18 ++--
 2 files changed, 50 insertions(+), 107 deletions(-)

diff --git a/packages/mdxld/src/render.test.ts b/packages/mdxld/src/render.test.ts
index 3d5a53893..ac4333cef 100644
--- a/packages/mdxld/src/render.test.ts
+++ b/packages/mdxld/src/render.test.ts
@@ -1,115 +1,60 @@
-import { render } from './render'
-import { describe, it, expect, vi, beforeEach } from 'vitest'
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest'
 import React from 'react'
-import * as mdx from '@mdx-js/mdx'
-import * as ReactDOMServer from 'react-dom/server'
-import TurndownService from 'turndown'
 
-vi.mock('@mdx-js/mdx', () => {
-  const mockCompile = vi.fn().mockResolvedValue('compiled-mdx-content')
-  const mockEvaluate = vi.fn().mockImplementation(() => {
-    return Promise.resolve({
-      default: () => React.createElement('div', null, 'Mocked MDX Component')
-    })
-  })
-  
-  return {
-    compile: mockCompile,
-    evaluate: mockEvaluate
-  }
-})
-
-vi.mock('react-dom/server', () => {
-  return {
-    renderToString: vi.fn().mockReturnValue('<div>Mocked MDX Component</div>')
-  }
-})
-
-vi.mock('turndown', () => {
-  return {
-    default: vi.fn().mockImplementation(() => ({
-      turndown: vi.fn().mockReturnValue('Rendered markdown content')
-    }))
-  }
-})
-
-describe('render', () => {
-  beforeEach(() => {
-    vi.clearAllMocks()
-  })
-
-  it('should render MDX content to markdown', async () => {
-    const mdxContent = `---
-title: Test Document
-tags: ["mdx", "test"]
----
-
-# Hello World
-
-This is a test document.`
+// Real compilation tests using actual @mdx-js/mdx
 
+describe('render - real compilation', () => {
+  it('renders markdown and parses frontmatter', async () => {
+    const { render } = await import('./render')
+    const mdxContent = `---\ntitle: Real Test\n---\n\n# Hello World`
     const result = await render(mdxContent)
-
-    expect(result.markdown).toBe('Rendered markdown content')
-    expect(result.frontmatter).toEqual({
-      title: 'Test Document',
-      tags: ['mdx', 'test'],
-    })
-    expect(mdx.compile).toHaveBeenCalled()
-    expect(mdx.evaluate).toHaveBeenCalled()
-    expect(ReactDOMServer.renderToString).toHaveBeenCalled()
+    expect(result.frontmatter).toEqual({ title: 'Real Test' })
+    expect(result.markdown).toContain('Hello World')
   })
 
-  it('should handle MDX content without frontmatter', async () => {
-    const mdxContent = `# Hello World
-
-This is a test document without frontmatter.`
-
+  it('handles content without frontmatter', async () => {
+    const { render } = await import('./render')
+    const mdxContent = `# Just Heading`
     const result = await render(mdxContent)
-
-    expect(result.markdown).toBe('Rendered markdown content')
     expect(result.frontmatter).toEqual({})
-    expect(mdx.compile).toHaveBeenCalled()
+    expect(result.markdown).toContain('Just Heading')
   })
+})
 
-  it('should pass components and scope to MDX rendering', async () => {
-    const mdxContent = `# Hello World
-
-<CustomComponent />`
-
-    const customComponents = {
-      CustomComponent: () => React.createElement('div', null, 'Custom content'),
-    }
-
-    const customScope = {
-      testVar: 'test value',
-    }
-
-    const result = await render(mdxContent, {
-      components: customComponents,
-      scope: customScope,
+describe('render - mocked mdx', () => {
+  beforeEach(() => {
+    vi.resetModules()
+    vi.doMock('@mdx-js/mdx', () => {
+      const mockEvaluate = vi.fn().mockResolvedValue({
+        default: () => React.createElement('div', null, 'Mocked MDX Component'),
+      })
+      return { evaluate: mockEvaluate }
     })
-
-    expect(result.markdown).toBe('Rendered markdown content')
-    expect(mdx.evaluate).toHaveBeenCalledWith(expect.anything(), expect.objectContaining({
-      ...customScope
+    vi.doMock('react-dom/server', () => ({
+      renderToString: vi.fn().mockReturnValue('<div>Mocked MDX Component</div>'),
+    }))
+    vi.doMock('turndown', () => ({
+      default: vi.fn().mockImplementation(() => ({
+        turndown: vi.fn().mockReturnValue('Rendered markdown content'),
+      })),
     }))
-    expect(ReactDOMServer.renderToString).toHaveBeenCalledWith(
-      expect.objectContaining({
-        props: expect.objectContaining({
-          components: customComponents
-        })
-      })
-    )
   })
 
-  it('should throw an error when MDX compilation fails', async () => {
-    vi.mocked(mdx.compile).mockRejectedValueOnce(new Error('Compilation error'))
-
-    const mdxContent = `# Invalid MDX
+  afterEach(() => {
+    vi.clearAllMocks()
+    vi.resetModules()
+  })
 
-<Component with syntax error />`
+  it('returns markdown using mocks', async () => {
+    const { render } = await import('./render')
+    const mdxContent = `# Test`
+    const result = await render(mdxContent)
+    expect(result.markdown).toBe('Rendered markdown content')
+  })
 
-    await expect(render(mdxContent)).rejects.toThrow('Failed to render MDX: Compilation error')
+  it('throws an error when evaluation fails', async () => {
+    vi.mocked((await import('@mdx-js/mdx')).evaluate).mockRejectedValueOnce(new Error('Compilation error'))
+    const { render } = await import('./render')
+    await expect(render('# Error')).rejects.toThrow('Failed to render MDX: Compilation error')
   })
 })
diff --git a/packages/mdxld/src/render.ts b/packages/mdxld/src/render.ts
index 80a6b09f6..b60cfc245 100644
--- a/packages/mdxld/src/render.ts
+++ b/packages/mdxld/src/render.ts
@@ -1,7 +1,8 @@
 import React from 'react'
-import { compile, evaluate } from '@mdx-js/mdx'
+import { evaluate } from '@mdx-js/mdx'
 import { VFile } from 'vfile'
 import * as runtime from 'react/jsx-runtime'
+import * as runtimeDev from 'react/jsx-dev-runtime'
 import * as ReactDOMServer from 'react-dom/server'
 import TurndownService from 'turndown'
 import { parseFrontmatter } from './parser.js'
@@ -44,20 +45,17 @@ export async function render(mdxContent: string, options: RenderOptions = {}): P
     const frontmatterRegex = /^\s*---\s*[\r\n]+([\s\S]*?)[\r\n]+---\s*[\r\n]+/
     const contentWithoutFrontmatter = mdxContent.replace(frontmatterRegex, '')
 
-    const compiled = await compile(new VFile(contentWithoutFrontmatter), {
-      jsx: true,
-      jsxImportSource: 'react',
+    const dev = process.env.NODE_ENV !== 'production'
+    const runtimeLib = dev ? runtimeDev : runtime
+    const { default: Component } = await evaluate(new VFile(contentWithoutFrontmatter), {
+      ...runtimeLib,
       remarkPlugins: [remarkGfm],
       rehypePlugins: [],
-      development: process.env.NODE_ENV !== 'production',
+      development: dev,
       format: 'mdx',
       recmaPlugins: [],
       mdExtensions: ['.md', '.mdx'],
-      elementAttributeNameCase: 'html'
-    })
-
-    const { default: Component } = await evaluate(compiled, {
-      ...runtime,
+      elementAttributeNameCase: 'html',
       ...options.scope,
     })