feat: add input validation to validateAgentContent for non-string input

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

Author: leocavalcante

src/paths.mjs

@@ -270,8 +270,14 @@ export function parseFrontmatter(content) {
  *
  * @param {string} content - The agent file content to validate
  * @returns {{ valid: boolean, error?: string }} Validation result with optional error message
+ * @throws {TypeError} If content is not a string
  */
 export function validateAgentContent(content) {
+	if (typeof content !== "string") {
+		throw new TypeError(
+			`validateAgentContent: content must be a string, got ${content === null ? "null" : typeof content}`,
+		)
+	}
 	// Check minimum length
 	if (content.length < MIN_CONTENT_LENGTH) {
 		return {

tests/paths.test.ts

@@ -791,6 +791,48 @@ This is a test agent that handles various tasks.
 			const result = validateAgentContent(content)
 			expect(result.valid).toBe(true)
 		})
+
+		it("should throw TypeError for null input", () => {
+			expect(() => validateAgentContent(null as unknown as string)).toThrow(TypeError)
+			expect(() => validateAgentContent(null as unknown as string)).toThrow(
+				"validateAgentContent: content must be a string, got null",
+			)
+		})
+
+		it("should throw TypeError for undefined input", () => {
+			expect(() => validateAgentContent(undefined as unknown as string)).toThrow(TypeError)
+			expect(() => validateAgentContent(undefined as unknown as string)).toThrow(
+				"validateAgentContent: content must be a string, got undefined",
+			)
+		})
+
+		it("should throw TypeError for number input", () => {
+			expect(() => validateAgentContent(123 as unknown as string)).toThrow(TypeError)
+			expect(() => validateAgentContent(123 as unknown as string)).toThrow(
+				"validateAgentContent: content must be a string, got number",
+			)
+		})
+
+		it("should throw TypeError for object input", () => {
+			expect(() => validateAgentContent({} as unknown as string)).toThrow(TypeError)
+			expect(() => validateAgentContent({} as unknown as string)).toThrow(
+				"validateAgentContent: content must be a string, got object",
+			)
+		})
+
+		it("should throw TypeError for array input", () => {
+			expect(() => validateAgentContent([] as unknown as string)).toThrow(TypeError)
+			expect(() => validateAgentContent([] as unknown as string)).toThrow(
+				"validateAgentContent: content must be a string, got object",
+			)
+		})
+
+		it("should throw TypeError for boolean input", () => {
+			expect(() => validateAgentContent(true as unknown as string)).toThrow(TypeError)
+			expect(() => validateAgentContent(true as unknown as string)).toThrow(
+				"validateAgentContent: content must be a string, got boolean",
+			)
+		})
 	})
 
 	describe("checkVersionCompatibility", () => {