feat(testing): add unit tests for ExitError and improve class definition

- Added `test/errors.test.mjs` with comprehensive tests for the `ExitError` class.
- Updated `src/errors.mjs` to set `this.name = 'ExitError'` in the constructor for better error reporting.
- Verified that all new tests pass and no regressions were introduced to the existing test suite.

Co-authored-by: PR0M3TH3AN <[email protected]>

src/errors.mjs

@@ -2,6 +2,7 @@
 export class ExitError extends Error {
   constructor(code, message) {
     super(message);
+    this.name = 'ExitError';
     this.code = code;
   }
 }

test/errors.test.mjs

@@ -0,0 +1,31 @@
+import { describe, it } from 'node:test';
+import assert from 'node:assert';
+import { ExitError } from '../src/errors.mjs';
+
+describe('ExitError', () => {
+  it('should capture the code and message correctly', () => {
+    const code = 1;
+    const message = 'Test error message';
+    const error = new ExitError(code, message);
+
+    assert.strictEqual(error.code, code);
+    assert.strictEqual(error.message, message);
+  });
+
+  it('should be an instance of Error and ExitError', () => {
+    const error = new ExitError(1, 'message');
+
+    assert.ok(error instanceof Error);
+    assert.ok(error instanceof ExitError);
+  });
+
+  it('should have a stack trace', () => {
+    const error = new ExitError(1, 'message');
+    assert.ok(error.stack);
+  });
+
+  it('should have the correct name', () => {
+    const error = new ExitError(1, 'message');
+    assert.strictEqual(error.name, 'ExitError');
+  });
+});