diff --git a/model/redis_recommend_test.go b/model/redis_recommend_test.go
index c611e68..3c5f4c4 100644
--- a/model/redis_recommend_test.go
+++ b/model/redis_recommend_test.go
@@ -99,3 +99,28 @@ func TestFallbackSpecificSetKey(t *testing.T) {
 		})
 	}
 }
+
+func TestShouldFallbackToInitialRecommend(t *testing.T) {
+	tests := []struct {
+		input string
+		want  bool
+	}{
+		{input: "", want: false},
+		{input: ".", want: true},
+		{input: ".x", want: true},
+		{input: "..x", want: true},
+		{input: "...x", want: true},
+		{input: "grid000", want: false},
+		{input: "grid000.", want: false},
+		{input: "grid000.zone000", want: false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.input, func(t *testing.T) {
+			got := shouldFallbackToInitialRecommend(tt.input)
+			if got != tt.want {
+				t.Fatalf("expected %t, got %t", tt.want, got)
+			}
+		})
+	}
+}