refactor(core): harden skill frontmatter parsing (#16705)

packages/core/src/skills/skillLoader.test.ts

@@ -194,4 +194,64 @@ Do something.
     expect(skills[0].description).toContain('Expertise in reviewing code');
     expect(skills[0].description).toContain('check');
   });
+
+  it('should handle empty name or description', async () => {
+    const skillDir = path.join(testRootDir, 'empty-skill');
+    await fs.mkdir(skillDir, { recursive: true });
+    const skillFile = path.join(skillDir, 'SKILL.md');
+    await fs.writeFile(
+      skillFile,
+      `---
+name: 
+description: 
+---
+`,
+    );
+
+    const skills = await loadSkillsFromDir(testRootDir);
+
+    expect(skills).toHaveLength(1);
+    expect(skills[0].name).toBe('');
+    expect(skills[0].description).toBe('');
+  });
+
+  it('should handle indented name and description fields', async () => {
+    const skillDir = path.join(testRootDir, 'indented-fields');
+    await fs.mkdir(skillDir, { recursive: true });
+    const skillFile = path.join(skillDir, 'SKILL.md');
+    await fs.writeFile(
+      skillFile,
+      `---
+  name: indented-name
+  description: indented-desc
+---
+`,
+    );
+
+    const skills = await loadSkillsFromDir(testRootDir);
+
+    expect(skills).toHaveLength(1);
+    expect(skills[0].name).toBe('indented-name');
+    expect(skills[0].description).toBe('indented-desc');
+  });
+
+  it('should handle missing space after colon', async () => {
+    const skillDir = path.join(testRootDir, 'no-space');
+    await fs.mkdir(skillDir, { recursive: true });
+    const skillFile = path.join(skillDir, 'SKILL.md');
+    await fs.writeFile(
+      skillFile,
+      `---
+name:no-space-name
+description:no-space-desc
+---
+`,
+    );
+
+    const skills = await loadSkillsFromDir(testRootDir);
+
+    expect(skills).toHaveLength(1);
+    expect(skills[0].name).toBe('no-space-name');
+    expect(skills[0].description).toBe('no-space-desc');
+  });
 });

packages/core/src/skills/skillLoader.ts

@@ -71,16 +71,22 @@ function parseSimpleFrontmatter(
   for (let i = 0; i < lines.length; i++) {
     const line = lines[i];
 
-    if (line.startsWith('name:')) {
-      name = line.substring(5).trim();
+    // Match "name:" at the start of the line (optional whitespace)
+    const nameMatch = line.match(/^\s*name:\s*(.*)$/);
+    if (nameMatch) {
+      name = nameMatch[1].trim();
       continue;
     }
 
-    if (line.startsWith('description:')) {
-      const descLines = [line.substring(12).trim()];
+    // Match "description:" at the start of the line (optional whitespace)
+    const descMatch = line.match(/^\s*description:\s*(.*)$/);
+    if (descMatch) {
+      const descLines = [descMatch[1].trim()];
 
+      // Check for multi-line description (indented continuation lines)
       while (i + 1 < lines.length) {
         const nextLine = lines[i + 1];
+        // If next line is indented, it's a continuation of the description
         if (nextLine.match(/^[ \t]+\S/)) {
           descLines.push(nextLine.trim());
           i++;
@@ -169,7 +175,7 @@ export async function loadSkillFromFile(
       name: frontmatter.name,
       description: frontmatter.description,
       location: filePath,
-      body: match[2].trim(),
+      body: match[2]?.trim() ?? '',
     };
   } catch (error) {
     debugLogger.log(`Error parsing skill file ${filePath}:`, error);