feat(metadata): expose OmitMetadata generic

src/checks/hasMetadata.test.ts

@@ -1,5 +1,5 @@
 import { hasMetadata } from '..';
-import { HasMetadata } from './hasMetadata';
+import { HasMetadata, OmitMetadata } from './hasMetadata';
 
 describe('HasMetadata', () => {
   it('should enable accessing an optional metadata property of a type', () => {
@@ -9,6 +9,23 @@ describe('HasMetadata', () => {
   });
 });
 
+describe('OmitMetadata', () => {
+  it('should prevent specifying a metadata property of a type', () => {
+    type FlowerPot = { id?: number; age: number };
+
+    // @ts-expect-error - should not be able to set id
+    const pot: OmitMetadata<FlowerPot> = { id: 123, age: 72 };
+  });
+  it('should prevent accessing a metadata property of a type', () => {
+    type FlowerPot = { id?: number; age: number };
+
+    const pot: OmitMetadata<FlowerPot> = { age: 72 };
+
+    // @ts-expect-error - should not be able to get id
+    expect(pot.id).not.toBeDefined();
+  });
+});
+
 describe('hasMetadata', () => {
   it('should enable accessing an optional metadata property of a type', () => {
     type FlowerPot = { id?: number; age: number };

src/checks/hasMetadata.ts

@@ -9,6 +9,7 @@ const typicalMetadataKeys = [
   'deletedAt',
   'effectiveAt',
 ] as const;
+
 /**
  * these are the keys most commonly used metadata keys
  */
@@ -44,6 +45,28 @@ export type HasMetadata<
     >
   >;
 
+/**
+ * asserts that any optional metadata keys of the object will now be omitted
+ *
+ * by default, the following keys are considered to be metadata:
+ * - `id`
+ * - `uuid`
+ * - `createdAt`
+ * - `updatedAt`
+ * - `deletedAt`
+ * - `effectiveAt`
+ */
+export type OmitMetadata<
+  T extends Record<string, any>,
+  MetadataKeys = TypicalMetadataKeys,
+> =
+  // omit all keys
+  Omit<
+    T,
+    keyof T & // that are on the object
+      MetadataKeys // and are metadata keys
+  >;
+
 /**
  * for an object of type T, asserts that the object HasMetadata<T, K> for all listed metadata keys K
  *