fix: probabilites not summing to 1

internal/core/engine_test.go

@@ -1,9 +1,12 @@
 package core
 
-import "testing"
+import (
+	"math"
+	"testing"
+)
 
 func TestGetStatsForTZs(t *testing.T) {
-	preds, err := getStatsForTZs([]string{"+0100", "+0000"})
+	preds, err := GetStatsForTZs([]string{"+0100", "+0000"})
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -12,3 +15,20 @@ func TestGetStatsForTZs(t *testing.T) {
 		t.Fatalf("failed to get predictions")
 	}
 }
+
+func TestPredSum(t *testing.T) {
+	preds, err := GetStatsForTZs([]string{"+0100"})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// sum must be 1
+	sum := 0.0
+	for _, pred := range preds {
+		sum += pred.Probability
+	}
+
+	if math.Abs(sum-1) > 1e-6 {
+		t.Fatalf("Probabilities did not sum to 1. Got %.4f instead", sum)
+	}
+}