tests: add backend tests

backend/pkg/values/values_test.go

@@ -0,0 +1,51 @@
+package values
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestFirstNonZero(t *testing.T) {
+	// Test with all zero values
+	result := FirstNonZero(0, 0, 0)
+	assert.Equal(t, 0, result)
+
+	// Test with first non-zero
+	result = FirstNonZero(0, 5, 10)
+	assert.Equal(t, 5, result)
+
+	// Test with middle non-zero
+	result = FirstNonZero(0, 0, 15, 0, 20)
+	assert.Equal(t, 15, result)
+
+	// Test with strings
+	resultStr := FirstNonZero("", "hello", "")
+	assert.Equal(t, "hello", resultStr)
+
+	// Test with empty strings (empty string is zero value for string)
+	resultStr = FirstNonZero("", "", "")
+	assert.Equal(t, "", resultStr)
+}
+
+func TestCountNonZero(t *testing.T) {
+	// Test with all zero values
+	count := CountNonZero(0, 0, 0)
+	assert.Equal(t, 0, count)
+
+	// Test with some non-zero values
+	count = CountNonZero(0, 5, 10)
+	assert.Equal(t, 2, count)
+
+	// Test with all non-zero values
+	count = CountNonZero(1, 2, 3, 4)
+	assert.Equal(t, 4, count)
+
+	// Test with strings
+	count = CountNonZero("", "hello", "", "world")
+	assert.Equal(t, 2, count)
+
+	// Test with empty slice
+	count = CountNonZero[int]()
+	assert.Equal(t, 0, count)
+}