diff --git a/src/app/pipes/array/diff.spec.ts b/src/app/pipes/array/diff.spec.ts
index db48beae..818c7761 100644
--- a/src/app/pipes/array/diff.spec.ts
+++ b/src/app/pipes/array/diff.spec.ts
@@ -7,6 +7,11 @@ describe('DiffPipe', () => {
     pipe = new DiffPipe();
   });
 
+  it('should return the input if not an array', () => {
+    expect(pipe.transform(true)).toEqual(true);
+    expect(pipe.transform(42)).toEqual(42);
+  });
+
   it('should keep the array the same way if it doesn\'t have any without arguments', () => {
     expect(pipe.transform([1, 2, 3])).toEqual([1, 2, 3]);
     expect(pipe.transform([])).toEqual([]);