added more int parsing and tests

env/duration_test.go

@@ -0,0 +1,42 @@
+package env
+
+import (
+	"os"
+	"testing"
+	"time"
+)
+
+func TestDuration(t *testing.T) {
+	tests := []struct {
+		name         string
+		key          string
+		value        string
+		defaultValue time.Duration
+		expected     time.Duration
+		shouldSet    bool
+	}{
+		{"valid positive duration", "TEST_DURATION", "100", 0, 100 * time.Nanosecond, true},
+		{"valid zero", "TEST_DURATION", "0", 10 * time.Second, 0, true},
+		{"large value", "TEST_DURATION", "1000000000", 0, 1 * time.Second, true},
+		{"valid negative duration", "TEST_DURATION", "-100", 0, -100 * time.Nanosecond, true},
+		{"not set", "TEST_DURATION_NOTSET", "", 5 * time.Minute, 5 * time.Minute, false},
+		{"invalid value", "TEST_DURATION", "not_a_number", 30 * time.Second, 30 * time.Second, true},
+		{"empty string", "TEST_DURATION", "", 1 * time.Hour, 1 * time.Hour, true},
+		{"float value", "TEST_DURATION", "10.5", 2 * time.Second, 2 * time.Second, true},
+		{"very large value", "TEST_DURATION", "9223372036854775807", 0, 9223372036854775807 * time.Nanosecond, true},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if tt.shouldSet {
+				os.Setenv(tt.key, tt.value)
+				defer os.Unsetenv(tt.key)
+			}
+
+			result := Duration(tt.key, tt.defaultValue)
+			if result != tt.expected {
+				t.Errorf("Duration() = %v, want %v", result, tt.expected)
+			}
+		})
+	}
+}