test(errors): add error tests

src/errors.test.ts

@@ -0,0 +1,36 @@
+import { FragmenterError, FragmenterErrorCode } from './errors';
+
+describe('FragmenterError', () => {
+    describe('isFragmenterError', () => {
+        it('identifies a FragmenterError', () => {
+            const error = FragmenterError.create(FragmenterErrorCode.PermissionsError, 'aw hell nah');
+
+            expect(FragmenterError.isFragmenterError(error)).toBeTruthy();
+        });
+
+        it('does not identify a not FragmenterError', () => {
+            const error = new Error('when the amogus imposter is sus');
+
+            expect(FragmenterError.isFragmenterError(error)).toBeFalsy();
+        });
+    });
+
+    describe('parseFromMessage', () => {
+        it('parses valid FragmenterError', () => {
+            const msg = 'FragmenterError(PermissionsError): EPERM';
+
+            const parsed = FragmenterError.parseFromMessage(msg);
+
+            expect(parsed.code).toBe(FragmenterErrorCode.PermissionsError);
+            expect(parsed.message).toBe('FragmenterError(PermissionsError): EPERM');
+        });
+
+        it('does not parse invalid FragmenterError', () => {
+            const msg = 'NotAFragmenterError(EPERM)';
+
+            expect(() => {
+                FragmenterError.parseFromMessage(msg);
+            }).toThrow(expect.objectContaining({ message: 'Could not parse FragmenterError: does not match regex' }));
+        });
+    });
+});