add tests where param is another operation

Signed-off-by: Saumya Shah <[email protected]>

Author: Saumya40-codes

engine/engine_test.go

@@ -1964,9 +1964,22 @@ sum by (grpc_method, grpc_code) (
 			end:   time.Unix(3000, 0),
 			step:  2 * time.Second,
 		},
+		{
+			name: "limitK by (series)",
+			load: `load 30s
+			    http_requests_total{pod="nginx-1", series="1"} 1+1.1x50
+			    http_requests_total{pod="nginx-2", series="1"} 2+2.3x50
+			    http_requests_total{pod="nginx-4", series="2"} 5+2.4x50
+			    http_requests_total{pod="nginx-5", series="2"} 8.4+2.3x50
+			    http_requests_total{pod="nginx-6", series="2"} 2.3+2.3x50`,
+			query: `limitk(2, http_requests_total) by (pod)`,
+			start: time.Unix(0, 0),
+			end:   time.Unix(3000, 0),
+			step:  2 * time.Second,
+		},
 		// TODO(Saumya40-Codes): uncomment once https://github.com/prometheus/prometheus/pull/16404 gets merged
 		// {
-		// 	name: "limitK but a sample not present at last few timestamps",
+		// 	name: "limitK but a sample might not present at last few timestamps",
 		// 	load: `load 30s
 		// 	    http_requests_total{pod="nginx-1", series="1"} 1+1.1x50
 		// 	    http_requests_total{pod="nginx-2", series="1"} 2+2.3x40
@@ -1978,19 +1991,6 @@ sum by (grpc_method, grpc_code) (
 		// 	end:   time.Unix(3000, 0),
 		// 	step:  2 * time.Second,
 		// },
-		// {
-		// 	name: "limitK by (pod)",
-		// 	load: `load 30s
-		// 	    http_requests_total{pod="nginx-1", series="1"} 1+1.1x50
-		// 	    http_requests_total{pod="nginx-2", series="1"} 2+2.3x40
-		// 	    http_requests_total{pod="nginx-4", series="2"} 5+2.4x50
-		// 	    http_requests_total{pod="nginx-5", series="2"} 8.4+2.3x50
-		// 	    http_requests_total{pod="nginx-6", series="2"} 2.3+2.3x50`,
-		// 	query: `limitk(2, http_requests_total) by (pod)`,
-		// 	start: time.Unix(0, 0),
-		// 	end:   time.Unix(3000, 0),
-		// 	step:  2 * time.Second,
-		// },
 		{
 			name: "sgn",
 			load: `load 30s
@@ -3616,6 +3616,19 @@ min without () (
 			    http_requests_total{pod="nginx-3", series="2"} 1`,
 			query: "limitk(2, http_requests_total) by (pod)",
 		},
+		{
+			name: "limitk(x, many-to-many join)",
+			load: `load 30s
+			    http_requests_total{pod="nginx-1", series="2"} 89
+			    http_requests_total{pod="nginx-1", series="1"} 49
+			    http_requests_total{pod="nginx-1", series="3"} 19
+			    http_requests_total{pod="nginx-2", series="2"} 12
+			    http_requests_total{pod="nginx-2", series="1"} 24
+			    http_requests_total{pod="nginx-3", series="3"} 8
+			    http_requests_total{pod="nginx-3", series="1"} 22
+			    http_requests_total{pod="nginx-3", series="2"} 1`,
+			query: "limitk(2, http_requests_total or limitk(2, sum without (series) (http_requests_total))) by (pod)",
+		},
 		{
 			name: "max",
 			load: `load 30s