null relationships should not be removed during preprocessing (#320)

Co-authored-by: Mathis Lucka <[email protected]>

Author: mathisdemos

src/api/ResourcefulApi.js

@@ -87,6 +87,10 @@ export class ResourcefulApi extends Api {
               type: startChar.charAt(0).toUpperCase() + relationship.data.type.slice(1)
             }
           }
+        } else if (relationship.data === null) {
+          relationships[name] = {
+            data: null
+          }
         }
       }
       data.data.relationships = relationships

test/api/ResourcefulApi.spec.js

@@ -39,3 +39,20 @@ test('reads the initial module list', () => {
 
   expect(registerModuleMock.mock.calls.length).toBe(3)
 })
+
+test('keeps null relationships after preprocessing', () => {
+  const testResource = {
+    data: {
+      id: 1,
+      type: 'User',
+      relationships: {
+        hobbies: {
+          data: null
+        }
+      }
+    }
+  }
+
+  const preprocessedData = api.preprocessData(testResource)
+  expect(preprocessedData.data.relationships.hobbies.data).toBe(null)
+})