pkg/stat: rename package name to singular form

Go package names should generally be singular form:

https://go.dev/blog/package-names
https://rakyll.org/style-packages
https://groups.google.com/g/golang-nuts/c/buBwLar1gNw

1 files changed, 66 insertions, 0 deletions

diff --git a/pkg/stat/sample/sample_test.go b/pkg/stat/sample/sample_test.go
new file mode 100644
index 000000000..ac7845ccf
--- /dev/null
+++ b/pkg/stat/sample/sample_test.go
@@ -0,0 +1,66 @@
+// Copyright 2021 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+package sample
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestMedian(t *testing.T) {
+	tests := []struct {
+		input     []float64
+		minMedian float64
+		maxMedian float64
+	}{
+		{
+			input:     []float64{1, 2, 3},
+			minMedian: 1.99, // we cannot do exact floating point equality comparison
+			maxMedian: 2.01,
+		},
+		{
+			input:     []float64{0, 1, 2, 3},
+			minMedian: 1.0,
+			maxMedian: 2.0,
+		},
+	}
+	for _, test := range tests {
+		sample := Sample{Xs: test.input}
+		median := sample.Median()
+		if median < test.minMedian || median > test.maxMedian {
+			t.Errorf("sample %v, median got %v, median expected [%v;%v]",
+				test.input, median, test.minMedian, test.maxMedian)
+		}
+	}
+}
+
+func TestRemoveOutliers(t *testing.T) {
+	// Some tests just to check the overall sanity of the method.
+	tests := []struct {
+		input  []float64
+		output []float64
+	}{
+		{
+			input:  []float64{-20, 1, 2, 3, 4, 5},
+			output: []float64{1, 2, 3, 4, 5},
+		},
+		{
+			input:  []float64{1, 2, 3, 4, 25},
+			output: []float64{1, 2, 3, 4},
+		},
+		{
+			input:  []float64{-10, -5, 0, 5, 10, 15},
+			output: []float64{-10, -5, 0, 5, 10, 15},
+		},
+	}
+	for _, test := range tests {
+		sample := Sample{Xs: test.input}
+		result := sample.RemoveOutliers()
+		result.Sort()
+		if !reflect.DeepEqual(result.Xs, test.output) {
+			t.Errorf("input: %v, expected no outliers: %v, got: %v",
+				test.input, test.output, result.Xs)
+		}
+	}
+}