diff --git a/controller/appcontroller_test.go b/controller/appcontroller_test.go
index a515f36583edc..6e965fc8f0972 100644
--- a/controller/appcontroller_test.go
+++ b/controller/appcontroller_test.go
@@ -2408,15 +2408,65 @@ func TestAppStatusIsReplaced(t *testing.T) {
 
 func TestAlreadyAttemptSync(t *testing.T) {
 	app := newFakeApp()
+
+	t.Run("no operation state", func(t *testing.T) {
+		app := app.DeepCopy()
+		app.Status.OperationState = nil
+		attempted, _ := alreadyAttemptedSync(app, "", []string{}, false, false)
+		assert.False(t, attempted)
+	})
+
+	t.Run("no sync operation", func(t *testing.T) {
+		app := app.DeepCopy()
+		app.Status.OperationState.Operation.Sync = nil
+		attempted, _ := alreadyAttemptedSync(app, "", []string{}, false, false)
+		assert.False(t, attempted)
+	})
+
+	t.Run("no sync result", func(t *testing.T) {
+		app := app.DeepCopy()
+		app.Status.OperationState.SyncResult = nil
+		attempted, _ := alreadyAttemptedSync(app, "", []string{}, false, false)
+		assert.False(t, attempted)
+	})
+
 	t.Run("same manifest with sync result", func(t *testing.T) {
 		attempted, _ := alreadyAttemptedSync(app, "sha", []string{}, false, false)
 		assert.True(t, attempted)
 	})
 
-	t.Run("different manifest with sync result", func(t *testing.T) {
+	t.Run("different manifest with sync result, different SHA", func(t *testing.T) {
+		app := app.DeepCopy()
+		app.Status.OperationState.SyncResult.Revision = "sha1"
+		attempted, _ := alreadyAttemptedSync(app, "sha2", []string{}, false, true)
+		assert.False(t, attempted)
+	})
+
+	t.Run("different manifest with sync result, same SHA", func(t *testing.T) {
+		app := app.DeepCopy()
+		app.Status.OperationState.SyncResult.Revision = "sha"
 		attempted, _ := alreadyAttemptedSync(app, "sha", []string{}, false, true)
+		assert.True(t, attempted)
+	})
+
+	t.Run("same manifest with sync result", func(t *testing.T) {
+		attempted, _ := alreadyAttemptedSync(app, "", []string{"sha"}, true, false)
+		assert.True(t, attempted)
+	})
+
+	t.Run("different manifest with sync result, different SHAs", func(t *testing.T) {
+		app := app.DeepCopy()
+		app.Status.OperationState.SyncResult.Revisions = []string{"sha_a_=", "sha_b_1"}
+		attempted, _ := alreadyAttemptedSync(app, "", []string{"sha_a_2", "sha_b_2"}, true, true)
 		assert.False(t, attempted)
 	})
+
+	t.Run("different manifest with sync result, same SHAs", func(t *testing.T) {
+		app := app.DeepCopy()
+		app.Status.OperationState.SyncResult.Revisions = []string{"sha_a", "sha_b"}
+		attempted, _ := alreadyAttemptedSync(app, "", []string{"sha_a", "sha_b"}, true, true)
+		assert.True(t, attempted)
+	})
 }
 
 func assertDurationAround(t *testing.T, expected time.Duration, actual time.Duration) {