fix: more pleasant error message

tests/lib/error.test.ts

@@ -0,0 +1,45 @@
+import { describe, expect, mock, test } from "bun:test";
+import z from "zod";
+import { formatUnknownError, wrapCommandErrors } from "../../lib/error";
+
+describe("CLI error handling", () => {
+  test("formats Zod errors without exposing internal parser details", () => {
+    const error = z.object({ name: z.string() }).safeParse({ name: 1 }).error;
+    expect(formatUnknownError(error)).toContain("name");
+    expect(formatUnknownError(error)).toContain("expected string");
+  });
+
+  test("catches errors from nested command handlers before Citty sees them", async () => {
+    const handleError = mock((_error: unknown) => {});
+    const command = {
+      subCommands: {
+        child: {
+          async run() {
+            throw new Error("command failed");
+          },
+        },
+      },
+    };
+
+    wrapCommandErrors(command, handleError);
+    await expect(command.subCommands.child.run()).resolves.toBeUndefined();
+    expect(handleError).toHaveBeenCalledTimes(1);
+    expect(handleError.mock.calls[0]?.[0]).toBeInstanceOf(Error);
+    expect(String(handleError.mock.calls[0]?.[0])).toContain("command failed");
+  });
+
+  test("formats a dispatched command error once and exits with code 1", async () => {
+    const process = Bun.spawn(["bun", "index.ts", "exec"], {
+      cwd: `${import.meta.dir}/../..`,
+      stdout: "pipe",
+      stderr: "pipe",
+    });
+    const [stderr, exitCode] = await Promise.all([
+      new Response(process.stderr).text(),
+      process.exited,
+    ]);
+
+    expect(exitCode).toBe(1);
+    expect(stderr.match(/Deployment name is required/g)).toHaveLength(1);
+  });
+});