fix median calculation for missing data in examples

Author: Tofel

book/src/libs/wasp/benchspy/loki_std.md

@@ -90,11 +90,13 @@ var compareMedian = func(metricName string) {
     previousMedian := benchspy.CalculatePercentile(previousFloatSlice, 0.5)
 
     var diffPercentage float64
-    if previousMedian != 0 {
-        diffPercentage = (currentMedian - previousMedian) / previousMedian * 100
-    } else {
-        diffPercentage = 100
-    }
+	if previousMedian != 0.0 && currentMedian != 0.0 {
+		diffPrecentage = (currentMedian - previousMedian) / previousMedian * 100
+	} else if previousMedian == 0.0 && currentMedian == 0.0 {
+		diffPrecentage = 0.0
+	} else {
+		diffPrecentage = 100.0
+	}
     assert.LessOrEqual(t, math.Abs(diffPercentage), 1.0, "%s medians are more than 1% different", metricName, fmt.Sprintf("%.4f", diffPercentage))
 }
 

book/src/libs/wasp/benchspy/simplest_metrics.md

@@ -36,10 +36,12 @@ var compareValues = func(
     previousMetric := previousAsFloat64[metricName]
 
     var diffPercentage float64
-    if previousMetric != 0.0 {
-        diffPercentage = (currentMetric - previousMetric) / previousMetric * 100
+    if previousMetric != 0.0 && currentMetric != 0.0 {
+        diffPrecentage = (currentMetric - previousMetric) / previousMetric * 100
+    } else if previousMetric == 0.0 && currentMetric == 0.0 {
+        diffPrecentage = 0.0
     } else {
-        diffPercentage = 100.0
+        diffPrecentage = 100.0
     }
     assert.LessOrEqual(t, math.Abs(diffPercentage), maxDiffPercentage, "%s medians are more than 1% different", metricName, fmt.Sprintf("%.4f", diffPercentage))
 }

wasp/examples/benchspy/direct_query_executor/direct_query_executor_test.go

@@ -88,12 +88,14 @@ func TestBenchSpy_Standard_Direct_Metrics(t *testing.T) {
 		previousMetric := previousAsloat64[metricName]
 
 		var diffPrecentage float64
-		if previousMetric != 0.0 {
+		if previousMetric != 0.0 && currentMetric != 0.0 {
 			diffPrecentage = (currentMetric - previousMetric) / previousMetric * 100
+		} else if previousMetric == 0.0 && currentMetric == 0.0 {
+			diffPrecentage = 0.0
 		} else {
 			diffPrecentage = 100.0
 		}
-		assert.LessOrEqual(t, math.Abs(diffPrecentage), maxDiffPercentage, "%s medians are more than 1% different", metricName, fmt.Sprintf("%.4f", diffPrecentage))
+		assert.LessOrEqual(t, math.Abs(diffPrecentage), maxDiffPercentage, "%s medians are more than %f different", metricName, fmt.Sprintf("%.4f", diffPrecentage))
 	}
 
 	compareValues(string(benchspy.MedianLatency), 1.0)

wasp/examples/benchspy/loki_query_executor/loki_query_executor_test.go

@@ -182,10 +182,12 @@ var compareMedian = func(t *testing.T, metricName string, currentAsStringSlice,
 	previousMedian := benchspy.CalculatePercentile(previousFloatSlice, 0.5)
 
 	var diffPrecentage float64
-	if previousMedian != 0 {
+	if previousMedian != 0.0 && currentMedian != 0.0 {
 		diffPrecentage = (currentMedian - previousMedian) / previousMedian * 100
+	} else if previousMedian == 0.0 && currentMedian == 0.0 {
+		diffPrecentage = 0.0
 	} else {
-		diffPrecentage = 100
+		diffPrecentage = 100.0
 	}
 	assert.LessOrEqual(t, math.Abs(diffPrecentage), 1.0, "%s medians are more than 1% different", metricName, fmt.Sprintf("%.4f", diffPrecentage))
 }

wasp/examples/benchspy/two_query_executors/two_query_executors_test.go

@@ -124,10 +124,12 @@ var compareMedian = func(t *testing.T, metricName string, currentAsStringSlice,
 	previousMedian := benchspy.CalculatePercentile(previousFloatSlice, 0.5)
 
 	var diffPrecentage float64
-	if previousMedian != 0 {
+	if previousMedian != 0.0 && currentMedian != 0.0 {
 		diffPrecentage = (currentMedian - previousMedian) / previousMedian * 100
+	} else if previousMedian == 0.0 && currentMedian == 0.0 {
+		diffPrecentage = 0.0
 	} else {
-		diffPrecentage = currentMedian * 100
+		diffPrecentage = 100.0
 	}
 	assert.LessOrEqual(t, math.Abs(diffPrecentage), 1.0, "%s medians are more than 1% different", metricName, fmt.Sprintf("%.4f", diffPrecentage))
 }