Improve error message formatting

Signed-off-by: Charles Korn <charles.korn@grafana.com>

promql/test.go

@@ -535,30 +535,30 @@ func (ev *evalCmd) compareResult(result parser.Value) error {
 			}
 
 			if len(expectedFloats) != len(s.Floats) || len(expectedHistograms) != len(s.Histograms) {
-				return fmt.Errorf("expected %v float points and %v histogram points for %s, but got %v float points %v and %v histogram points %v", len(expectedFloats), len(expectedHistograms), ev.metrics[hash], len(s.Floats), s.Floats, len(s.Histograms), s.Histograms)
+				return fmt.Errorf("expected %v float points and %v histogram points for %s, but got %s", len(expectedFloats), len(expectedHistograms), ev.metrics[hash], formatSeriesResult(s))
 			}
 
 			for i, expected := range expectedFloats {
 				actual := s.Floats[i]
 
 				if expected.T != actual.T {
-					return fmt.Errorf("expected float value at index %v for %s to have timestamp %v, but it had timestamp %v in result with %v float points %v and %v histogram points %v", i, ev.metrics[hash], expected.T, actual.T, len(s.Floats), s.Floats, len(s.Histograms), s.Histograms)
+					return fmt.Errorf("expected float value at index %v for %s to have timestamp %v, but it had timestamp %v (result has %s)", i, ev.metrics[hash], expected.T, actual.T, formatSeriesResult(s))
 				}
 
 				if !almostEqual(actual.F, expected.F, defaultEpsilon) {
-					return fmt.Errorf("expected float value at index %v (t=%v) for %s to be %v, but got %v in result with %v float points %v and %v histogram points %v", i, actual.T, ev.metrics[hash], expected.F, actual.F, len(s.Floats), s.Floats, len(s.Histograms), s.Histograms)
+					return fmt.Errorf("expected float value at index %v (t=%v) for %s to be %v, but got %v (result has %s)", i, actual.T, ev.metrics[hash], expected.F, actual.F, formatSeriesResult(s))
 				}
 			}
 
 			for i, expected := range expectedHistograms {
 				actual := s.Histograms[i]
 
 				if expected.T != actual.T {
-					return fmt.Errorf("expected histogram value at index %v for %s to have timestamp %v, but it had timestamp %v in result with %v float points %v and %v histogram points %v", i, ev.metrics[hash], expected.T, actual.T, len(s.Floats), s.Floats, len(s.Histograms), s.Histograms)
+					return fmt.Errorf("expected histogram value at index %v for %s to have timestamp %v, but it had timestamp %v (result has %s)", i, ev.metrics[hash], expected.T, actual.T, formatSeriesResult(s))
 				}
 
 				if !actual.H.Equals(expected.H) {
-					return fmt.Errorf("expected histogram value at index %v (t=%v) for %s to be %v, but got %v in result with %v float points %v and %v histogram points %v", i, actual.T, ev.metrics[hash], expected.H, actual.H, len(s.Floats), s.Floats, len(s.Histograms), s.Histograms)
+					return fmt.Errorf("expected histogram value at index %v (t=%v) for %s to be %v, but got %v (result has %s)", i, actual.T, ev.metrics[hash], expected.H, actual.H, formatSeriesResult(s))
 				}
 			}
 
@@ -630,20 +630,19 @@ func (ev *evalCmd) compareResult(result parser.Value) error {
 	return nil
 }
 
-func formatFloatAndHistogramPoints(floats []FPoint, histograms []HPoint) string {
-	if len(histograms) == 0 && len(floats) == 0 {
-		return "[]"
-	}
+func formatSeriesResult(s Series) string {
+	floatPlural := "s"
+	histogramPlural := "s"
 
-	if len(histograms) != 0 && len(floats) != 0 {
-		return fmt.Sprintf("floats: %v, histograms: %v", floats, histograms)
+	if len(s.Floats) == 1 {
+		floatPlural = ""
 	}
 
-	if len(histograms) != 0 {
-		return fmt.Sprintf("%v", histograms)
+	if len(s.Histograms) == 1 {
+		histogramPlural = ""
 	}
 
-	return fmt.Sprintf("%v", floats)
+	return fmt.Sprintf("%v float point%s %v and %v histogram point%s %v", len(s.Floats), floatPlural, s.Floats, len(s.Histograms), histogramPlural, s.Histograms)
 }
 
 // HistogramTestExpression returns TestExpression() for the given histogram or "" if the histogram is nil.

promql/test_test.go

@@ -295,7 +295,7 @@ eval range from 0 to 10m step 5m sum by (group) (http_requests)
 	{group="production"} 0 30 60
 	{group="canary"} 0 80 140
 `,
-			expectedError: `error in eval sum by (group) (http_requests) (line 8): expected float value at index 1 (t=300000) for {group="canary"} to be 80, but got 70 in result with 3 float points [0 @[0] 70 @[300000] 140 @[600000]] and 0 histogram points []`,
+			expectedError: `error in eval sum by (group) (http_requests) (line 8): expected float value at index 1 (t=300000) for {group="canary"} to be 80, but got 70 (result has 3 float points [0 @[0] 70 @[300000] 140 @[600000]] and 0 histogram points [])`,
 		},
 		"range query with expected histogram values": {
 			input: `
@@ -314,7 +314,7 @@ load 5m
 eval range from 0 to 10m step 5m testmetric
 	testmetric {{schema:-1 sum:4 count:1 buckets:[1] offset:1}} {{schema:-1 sum:7 count:1 buckets:[1] offset:1}} {{schema:-1 sum:8 count:1 buckets:[1] offset:1}}
 `,
-			expectedError: `error in eval testmetric (line 5): expected histogram value at index 1 (t=300000) for {__name__="testmetric"} to be {count:1, sum:7, (1,4]:1}, but got {count:1, sum:5, (1,4]:1} in result with 0 float points [] and 3 histogram points [{count:1, sum:4, (1,4]:1} @[0] {count:1, sum:5, (1,4]:1} @[300000] {count:1, sum:6, (1,4]:1} @[600000]]`,
+			expectedError: `error in eval testmetric (line 5): expected histogram value at index 1 (t=300000) for {__name__="testmetric"} to be {count:1, sum:7, (1,4]:1}, but got {count:1, sum:5, (1,4]:1} (result has 0 float points [] and 3 histogram points [{count:1, sum:4, (1,4]:1} @[0] {count:1, sum:5, (1,4]:1} @[300000] {count:1, sum:6, (1,4]:1} @[600000]])`,
 		},
 		"range query with too many points for query time range": {
 			input: testData + `
@@ -332,7 +332,7 @@ load 5m
 eval range from 0 to 6m step 6m testmetric
 	testmetric 5 10
 `,
-			expectedError: `error in eval testmetric (line 5): expected 2 float points and 0 histogram points for {__name__="testmetric"}, but got 1 float points [5 @[0]] and 0 histogram points []`,
+			expectedError: `error in eval testmetric (line 5): expected 2 float points and 0 histogram points for {__name__="testmetric"}, but got 1 float point [5 @[0]] and 0 histogram points []`,
 		},
 		"range query with extra point in result": {
 			input: testData + `
@@ -432,7 +432,7 @@ load 5m
 eval range from 0 to 5m step 5m testmetric
 	testmetric {{}} 3
 `,
-			expectedError: `error in eval testmetric (line 5): expected float value at index 0 for {__name__="testmetric"} to have timestamp 300000, but it had timestamp 0 in result with 1 float points [3 @[0]] and 1 histogram points [{count:0, sum:0} @[300000]]`,
+			expectedError: `error in eval testmetric (line 5): expected float value at index 0 for {__name__="testmetric"} to have timestamp 300000, but it had timestamp 0 (result has 1 float point [3 @[0]] and 1 histogram point [{count:0, sum:0} @[300000]])`,
 		},
 	}