chore: add various tests

pkg/sliceutils/sliceutils_test.go

@@ -0,0 +1,50 @@
+package sliceutils
+
+import (
+	"testing"
+)
+
+func TestFirst(t *testing.T) {
+	// Test with empty slice
+	var empty []int
+	result, ok := First(empty)
+	if ok != false {
+		t.Errorf("Expected ok=false for empty slice, got %v", ok)
+	}
+	if result != 0 {
+		t.Errorf("Expected zero value for empty slice, got %v", result)
+	}
+
+	// Test with non-empty slice
+	testSlice := []int{1, 2, 3}
+	result, ok = First(testSlice)
+	if ok != true {
+		t.Errorf("Expected ok=true for non-empty slice, got %v", ok)
+	}
+	if result != 1 {
+		t.Errorf("Expected first element, got %v", result)
+	}
+}
+
+func TestMap(t *testing.T) {
+	// Test with empty slice
+	var empty []int
+	result := Map(empty, func(x int) int { return x * 2 })
+	if len(result) != 0 {
+		t.Errorf("Expected empty result for empty input, got %v", result)
+	}
+
+	// Test with non-empty slice
+	testSlice := []int{1, 2, 3}
+	result = Map(testSlice, func(x int) int { return x * 2 })
+	expected := []int{2, 4, 6}
+	if len(result) != len(expected) {
+		t.Errorf("Expected length %d, got %d", len(expected), len(result))
+	}
+	for i, v := range result {
+		if v != expected[i] {
+			t.Errorf("Expected %d at index %d, got %d", expected[i], i, v)
+		}
+	}
+}
+