From d13062b81146ccb8a1f3b7d4d0f609a40c684eca Mon Sep 17 00:00:00 2001
From: AndrewDanilin <andnilin@gmail.com>
Date: Tue, 12 Sep 2023 21:16:06 +0300
Subject: [PATCH] [#88] netmap: fix min aggregator bug, add tests

Signed-off-by: Andrew Danilin <andnilin@gmail.com>
---
 netmap/aggregator.go      | 12 +++++++----
 netmap/aggregator_test.go | 44 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+), 4 deletions(-)
 create mode 100644 netmap/aggregator_test.go

diff --git a/netmap/aggregator.go b/netmap/aggregator.go
index c018e6b..3365fe3 100644
--- a/netmap/aggregator.go
+++ b/netmap/aggregator.go
@@ -23,7 +23,7 @@ type (
 	}
 
 	minAgg struct {
-		min float64
+		min *float64
 	}
 
 	meanIQRAgg struct {
@@ -102,13 +102,17 @@ func (a *meanAgg) Compute() float64 {
 }
 
 func (a *minAgg) Add(n float64) {
-	if a.min == 0 || n < a.min {
-		a.min = n
+	if a.min == nil || n < *a.min {
+		a.min = &n
 	}
 }
 
 func (a *minAgg) Compute() float64 {
-	return a.min
+	if a.min == nil {
+		return 0
+	}
+
+	return *a.min
 }
 
 func (a *meanIQRAgg) Add(n float64) {
diff --git a/netmap/aggregator_test.go b/netmap/aggregator_test.go
new file mode 100644
index 0000000..d844803
--- /dev/null
+++ b/netmap/aggregator_test.go
@@ -0,0 +1,44 @@
+package netmap
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestMinAgg(t *testing.T) {
+	tests := []struct {
+		vals []float64
+		res  float64
+	}{
+		{
+			vals: []float64{1, 2, 3, 0, 10},
+			res:  0,
+		},
+		{
+			vals: []float64{10, 0, 10, 0},
+			res:  0,
+		},
+		{
+			vals: []float64{0, 1, 2, 3, 10},
+			res:  0,
+		},
+		{
+			vals: []float64{0, 0, 0, 0},
+			res:  0,
+		},
+		{
+			vals: []float64{10, 10, 10, 10},
+			res:  10,
+		},
+	}
+
+	for _, test := range tests {
+		a := newMinAgg()
+		for _, val := range test.vals {
+			a.Add(val)
+		}
+
+		require.Equal(t, test.res, a.Compute())
+	}
+}