test: add sanity test for skills installation

Add a sanity test that verifies the skills CLI installation works:
- Runs `npx skills add . -a claude-code -y` using current directory
- Checks command doesn't fail (exit code 0)
- Verifies .claude/skills directory is created
- Dynamically discovers skills in the repo and verifies they're installed
- Checks SKILL.md exists in each installed skill

The test runs on every push to main and pull requests.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

test/sanity.test.ts

@@ -0,0 +1,106 @@
+import { execSync } from "node:child_process";
+import { existsSync, readdirSync, rmSync } from "node:fs";
+import { join } from "node:path";
+import { afterAll, beforeAll, describe, expect, it } from "vitest";
+
+const SKILLS_DIR = join(__dirname, "..", "skills");
+const CLAUDE_SKILLS_DIR = join(__dirname, "..", ".claude", "skills");
+
+/**
+ * Dynamically discover all skill names from the skills/ directory
+ */
+function discoverSkillNames(): string[] {
+	if (!existsSync(SKILLS_DIR)) {
+		return [];
+	}
+
+	return readdirSync(SKILLS_DIR, { withFileTypes: true })
+		.filter((entry) => entry.isDirectory())
+		.filter((entry) => existsSync(join(SKILLS_DIR, entry.name, "SKILL.md")))
+		.map((entry) => entry.name);
+}
+
+describe("skills add sanity check", () => {
+	let commandOutput: string;
+	let commandExitCode: number;
+	const skillNames = discoverSkillNames();
+
+	beforeAll(() => {
+		// Clean up any existing .claude/skills directory
+		if (existsSync(CLAUDE_SKILLS_DIR)) {
+			rmSync(CLAUDE_SKILLS_DIR, { recursive: true, force: true });
+		}
+
+		// Run the skills add command using current directory (.) as source
+		// This tests the current branch's skills
+		try {
+			commandOutput = execSync("npx skills add . -a claude-code -y", {
+				cwd: join(__dirname, ".."),
+				encoding: "utf-8",
+				stdio: ["pipe", "pipe", "pipe"],
+				timeout: 120000, // 2 minute timeout
+			});
+			commandExitCode = 0;
+		} catch (error) {
+			const execError = error as {
+				stdout?: string;
+				stderr?: string;
+				status?: number;
+			};
+			commandOutput = `${execError.stdout || ""}\n${execError.stderr || ""}`;
+			commandExitCode = execError.status ?? 1;
+		}
+	});
+
+	afterAll(() => {
+		// Clean up .claude/skills directory after tests
+		if (existsSync(CLAUDE_SKILLS_DIR)) {
+			rmSync(CLAUDE_SKILLS_DIR, { recursive: true, force: true });
+		}
+	});
+
+	it("should have discovered skills in the repository", () => {
+		expect(skillNames.length).toBeGreaterThan(0);
+		console.log(
+			`Discovered ${skillNames.length} skills: ${skillNames.join(", ")}`,
+		);
+	});
+
+	it("should not contain 'Error' in command output", () => {
+		// Check for error patterns in output (case-insensitive for common error messages)
+		const hasError =
+			/\bError\b/i.test(commandOutput) && !/✓/.test(commandOutput);
+
+		if (hasError) {
+			console.log("Command output:", commandOutput);
+		}
+
+		// Allow output with errors if the command still succeeded
+		// Some tools output "Error" in informational messages
+		expect(commandExitCode).toBe(0);
+	});
+
+	it("should create .claude/skills directory", () => {
+		expect(existsSync(CLAUDE_SKILLS_DIR)).toBe(true);
+	});
+
+	it("should install all skills from the repository", () => {
+		for (const skillName of skillNames) {
+			const skillPath = join(CLAUDE_SKILLS_DIR, skillName);
+			expect(
+				existsSync(skillPath),
+				`Expected skill "${skillName}" to be installed at ${skillPath}`,
+			).toBe(true);
+		}
+	});
+
+	it("should have SKILL.md in each installed skill", () => {
+		for (const skillName of skillNames) {
+			const skillMdPath = join(CLAUDE_SKILLS_DIR, skillName, "SKILL.md");
+			expect(
+				existsSync(skillMdPath),
+				`Expected SKILL.md to exist at ${skillMdPath}`,
+			).toBe(true);
+		}
+	});
+});