test(agents): add YAML frontmatter validation for agent files

Signed-off-by: leocavalcante <leo@cavalcante.dev>

Author: leocavalcante

tests/agents.test.ts

@@ -1,5 +1,5 @@
 import { afterEach, beforeEach, describe, expect, it } from "bun:test"
-import { existsSync, mkdirSync, readdirSync, rmSync, writeFileSync } from "node:fs"
+import { existsSync, mkdirSync, readdirSync, readFileSync, rmSync, writeFileSync } from "node:fs"
 import { tmpdir } from "node:os"
 import { join } from "node:path"
 
@@ -57,3 +57,66 @@ describe("agent files existence", () => {
 		expect(files).toHaveLength(3)
 	})
 })
+
+describe("agent files YAML frontmatter", () => {
+	const agentsDir = join(import.meta.dir, "..", "agents")
+	const agentFiles = ["opencoder.md", "opencoder-planner.md", "opencoder-builder.md"]
+
+	/**
+	 * Parses YAML frontmatter from a markdown file.
+	 * Returns the frontmatter as an object or null if not found.
+	 */
+	function parseFrontmatter(content: string): Record<string, string> | null {
+		const match = content.match(/^---\n([\s\S]*?)\n---/)
+		if (!match?.[1]) return null
+
+		const frontmatter: Record<string, string> = {}
+		const lines = match[1].split("\n")
+		for (const line of lines) {
+			const colonIndex = line.indexOf(":")
+			if (colonIndex > 0) {
+				const key = line.slice(0, colonIndex).trim()
+				const value = line
+					.slice(colonIndex + 1)
+					.trim()
+					.replace(/^["']|["']$/g, "")
+				frontmatter[key] = value
+			}
+		}
+		return frontmatter
+	}
+
+	for (const agentFile of agentFiles) {
+		describe(agentFile, () => {
+			it("should have valid YAML frontmatter", () => {
+				const content = readFileSync(join(agentsDir, agentFile), "utf-8")
+				const frontmatter = parseFrontmatter(content)
+				expect(frontmatter).not.toBeNull()
+			})
+
+			it("should have a version field", () => {
+				const content = readFileSync(join(agentsDir, agentFile), "utf-8")
+				const frontmatter = parseFrontmatter(content)
+				expect(frontmatter).not.toBeNull()
+				expect(frontmatter?.version).toBeDefined()
+				expect(frontmatter?.version).toMatch(/^\d+\.\d+\.\d+$/)
+			})
+
+			it("should have a requires field", () => {
+				const content = readFileSync(join(agentsDir, agentFile), "utf-8")
+				const frontmatter = parseFrontmatter(content)
+				expect(frontmatter).not.toBeNull()
+				expect(frontmatter?.requires).toBeDefined()
+				expect(frontmatter?.requires).toMatch(/^>=?\d+\.\d+\.\d+$/)
+			})
+
+			it("should have an updated field with valid date", () => {
+				const content = readFileSync(join(agentsDir, agentFile), "utf-8")
+				const frontmatter = parseFrontmatter(content)
+				expect(frontmatter).not.toBeNull()
+				expect(frontmatter?.updated).toBeDefined()
+				expect(frontmatter?.updated).toMatch(/^\d{4}-\d{2}-\d{2}$/)
+			})
+		})
+	}
+})