feat(metadata): add support for standard YAML frontmatter blocks

Author: moshams272

src/generators/metadata/utils/__tests__/yaml.test.mjs

@@ -1,7 +1,11 @@
 import { strictEqual, deepStrictEqual } from 'node:assert';
 import { describe, it } from 'node:test';
 
-import { parseYAMLIntoMetadata, normalizeYamlSyntax } from '../yaml.mjs';
+import {
+  parseYAMLIntoMetadata,
+  normalizeYamlSyntax,
+  extractYamlContent,
+} from '../yaml.mjs';
 
 describe('normalizeYamlSyntax', () => {
   it('should normalize YAML syntax by fixing noncompliant properties', () => {
@@ -65,3 +69,18 @@ describe('parseYAMLIntoMetadata', () => {
     deepStrictEqual(parseYAMLIntoMetadata(input), expectedOutput);
   });
 });
+
+describe('extractYamlContent', () => {
+  it('should extract content from a legacy HTML comment node', () => {
+    const node = {
+      type: 'html',
+      value: '<!-- YAML\nintroduced_in=v1.0.0\n-->',
+    };
+    strictEqual(extractYamlContent(node).trim(), 'introduced_in=v1.0.0');
+  });
+
+  it('should extract content directly from a standard YAML node', () => {
+    const node = { type: 'yaml', value: 'introduced_in: v1.0.0' };
+    strictEqual(extractYamlContent(node), 'introduced_in: v1.0.0');
+  });
+});

src/generators/metadata/utils/yaml.mjs

@@ -7,15 +7,17 @@ import { QUERIES } from '../../../utils/queries/index.mjs';
 /**
  * Extracts raw YAML content from a node
  *
- * @param {import('mdast').Node} node A HTML node containing the YAML content
+ * @param {import('mdast').Node} node A HTML or YAML node containing the YAML content
  * @returns {string} The extracted raw YAML content
  */
 export const extractYamlContent = node => {
-  return node.value.replace(
-    QUERIES.yamlInnerContent,
-    // Either capture a YAML multinline block, or a simple single-line YAML block
-    (_, simple, yaml) => simple || yaml
-  );
+  return node.type === 'yaml'
+    ? node.value
+    : node.value.replace(
+        QUERIES.yamlInnerContent,
+        // Either capture a YAML multinline block, or a simple single-line YAML block
+        (_, simple, yaml) => simple || yaml
+      );
 };
 
 /**

src/utils/queries/index.mjs

@@ -34,11 +34,12 @@ export const UNIST = {
     QUERIES.stabilityIndex.test(transformNodesToString(children)),
 
   /**
-   * @param {import('@types/mdast').Html} html
+   * @param {import('@types/mdast').Html | import('mdast').Node} node
    * @returns {boolean}
    */
   isYamlNode: ({ type, value }) =>
-    type === 'html' && QUERIES.yamlInnerContent.test(value),
+    type === 'yaml' ||
+    (type === 'html' && QUERIES.yamlInnerContent.test(value)),
 
   /**
    * @param {import('@types/mdast').Text} text