Use snapshot-fixtures for testing

This saves some boilerplate code.

package.json

@@ -43,11 +43,11 @@
     "eslint-config-remcohaszing": "^10.0.0",
     "eslint-plugin-jsx-a11y": "^6.0.0",
     "eslint-plugin-react": "^7.0.0",
+    "prettier": "^3.0.0",
     "rehype-raw": "^7.0.0",
     "remark-cli": "^11.0.0",
     "remark-preset-remcohaszing": "^2.0.0",
-    "prettier": "^3.0.0",
-    "to-vfile": "^8.0.0",
+    "snapshot-fixtures": "^1.0.0",
     "typescript": "^5.0.0"
   }
 }

src/rehype-mdx-import-media.test.ts

@@ -1,34 +1,19 @@
-import assert from 'node:assert/strict'
-import { readdir, readFile, writeFile } from 'node:fs/promises'
-import { test } from 'node:test'
-
-import { compile } from '@mdx-js/mdx'
-import prettier from 'prettier'
-import rehypeMdxImportMedia from 'rehype-mdx-import-media'
+import { compileSync } from '@mdx-js/mdx'
+import rehypeMdxImportMedia, { type RehypeMdxImportMediaOptions } from 'rehype-mdx-import-media'
 import rehypeRaw from 'rehype-raw'
-import { read } from 'to-vfile'
-
-const fixturesDir = new URL('../fixtures/', import.meta.url)
-const tests = await readdir(fixturesDir)
+import { testFixturesDirectory } from 'snapshot-fixtures'
 
-for (const name of tests) {
-  test(name, async () => {
-    const path = new URL(`${name}/`, fixturesDir)
-    const input = await read(new URL('input.md', path))
-    const expected = new URL('expected.jsx', path)
-    const options = JSON.parse(await readFile(new URL('options.json', path), 'utf8'))
-    const result = await compile(input, {
-      rehypePlugins: [rehypeRaw, [rehypeMdxImportMedia, options]],
-      jsx: true
-    })
-    const prettierConfig = await prettier.resolveConfig(expected.pathname, { editorconfig: true })
-    const output = await prettier.format(
-      String(result),
-      { ...prettierConfig, filepath: expected.pathname }!
-    )
-    if (process.argv.includes('update')) {
-      await writeFile(expected, output)
+testFixturesDirectory<RehypeMdxImportMediaOptions>({
+  directory: new URL('../fixtures', import.meta.url),
+  prettier: true,
+  tests: {
+    'expected.jsx'(file, options) {
+      return String(
+        compileSync(file, {
+          rehypePlugins: [rehypeRaw, [rehypeMdxImportMedia, options]],
+          jsx: true
+        })
+      )
     }
-    assert.equal(output, await readFile(expected, 'utf8'))
-  })
-}
+  }
+})