fix(devexp): make unexpected domain object errors more helpful

src/manipulation/getUniqueIdentifier.ts

@@ -4,6 +4,7 @@ import { assertDomainObjectIsSafeToManipulate } from '../constraints/assertDomai
 import { DomainEntity } from '../instantiation/DomainEntity';
 import { DomainObject } from '../instantiation/DomainObject';
 import { DomainValueObject } from '../instantiation/DomainValueObject';
+import { UnexpectedCodePathError } from '../utils/errors/UnexpectedCodePathError';
 import { DomainEntityUniqueKeysMustBeDefinedError } from './DomainEntityUniqueKeysMustBeDefinedError';
 
 /**
@@ -46,5 +47,11 @@ export const getUniqueIdentifier = <T extends Record<string, any>>(
   }
 
   // throw error we get here, this is unexpected
-  throw new Error('unexpected domain object type');
+  throw new UnexpectedCodePathError(
+    'unexpected domain object type for getUniqueIdentifier. expected DomainValueObject or DomainEntity',
+    {
+      dobjClass: (obj as any)?.constructor?.name,
+      dobj: obj,
+    },
+  );
 };

src/manipulation/getUpdatableProperties.ts

@@ -3,6 +3,7 @@ import pick from 'lodash.pick';
 import { assertDomainObjectIsSafeToManipulate } from '../constraints/assertDomainObjectIsSafeToManipulate';
 import { DomainEntity } from '../instantiation/DomainEntity';
 import { DomainObject } from '../instantiation/DomainObject';
+import { UnexpectedCodePathError } from '../utils/errors/UnexpectedCodePathError';
 import { DomainEntityUpdatablePropertiesMustBeDefinedError } from './DomainEntityUpdatablePropertiesMustBeDefinedError';
 
 /**
@@ -38,5 +39,11 @@ export const getUpdatableProperties = <T extends Record<string, any>>(
   }
 
   // throw error we get here, this is unexpected
-  throw new Error('unexpected domain object type');
+  throw new UnexpectedCodePathError(
+    'unexpected domain object type for getUpdatableProperties. expected DomainEntity',
+    {
+      dobjClass: (dobj as any)?.constructor?.name,
+      dobj,
+    },
+  );
 };

src/utils/errors/UnexpectedCodePathError.ts

@@ -0,0 +1,14 @@
+/**
+ * UnexpectedCodePath errors are used to indicate that we've reached a code path that should never have been reached
+ *
+ * Purpose of having a dedicated class for this type of error is to allow us to easily add metadata about what was going on when we reached this code path
+ * - e.g., the variables in memory at the time
+ */
+export class UnexpectedCodePathError extends Error {
+  constructor(message: string, metadata?: Record<string, any>) {
+    const fullMessage = `UnexpectedCodePath: ${message}${
+      metadata ? `\n\n${JSON.stringify(metadata)}` : ''
+    }`;
+    super(fullMessage);
+  }
+}