fix(db-mongodb): add validation to relationship ids (#8395)

fixes https://github.com/payloadcms/payload/issues/8652

packages/db-mongodb/src/utilities/sanitizeRelationshipIDs.ts

@@ -1,7 +1,7 @@
 import type { CollectionConfig, Field, SanitizedConfig, TraverseFieldsCallback } from 'payload'
 
 import mongoose from 'mongoose'
-import { traverseFields } from 'payload'
+import { APIError, traverseFields } from 'payload'
 import { fieldAffectsData } from 'payload/shared'
 
 type Args = {
@@ -31,7 +31,14 @@ const convertValue = ({
   )
 
   if (!customIDField) {
-    return new mongoose.Types.ObjectId(value)
+    try {
+      return new mongoose.Types.ObjectId(value)
+    } catch (error) {
+      throw new APIError(
+        `Failed to create ObjectId from value: ${value}. Error: ${error.message}`,
+        400,
+      )
+    }
   }
 
   return value

test/database/int.spec.ts

@@ -741,4 +741,25 @@ describe('database', () => {
       }),
     ).rejects.toThrow(QueryError)
   })
+
+  it('should not allow document creation with relationship data to an invalid document ID', async () => {
+    let invalidDoc
+
+    try {
+      invalidDoc = await payload.create({
+        collection: 'relation-b',
+        data: { title: 'invalid', relationship: 'not-real-id' },
+      })
+    } catch (error) {
+      expect(error).toBeInstanceOf(Error)
+    }
+
+    expect(invalidDoc).toBeUndefined()
+
+    const relationBDocs = await payload.find({
+      collection: 'relation-b',
+    })
+
+    expect(relationBDocs.docs).toHaveLength(0)
+  })
 })