Added a test for the empty unit, moved bad unit test into a separate test function

free/main.go

@@ -23,7 +23,7 @@ func ConvertUnit(stringUnit string) (jsh.Unit, error) {
 		return jsh.GB, nil
 	case "tB":
 		return jsh.TB, nil
-	case "":
+	case "": // On some systems (Arch, for example) bytes are just the empty string
 		return jsh.B, nil
 	default:
 		return 0, errors.New(fmt.Sprintf("Unknown unit: %s\n", stringUnit))

free/main_test.go

@@ -24,11 +24,23 @@ func TestConvertUnit(t *testing.T) {
 	testUnitError(jsh.GB, t)
 	testUnitError(jsh.TB, t)
 
+	// Test the empty unit, because this exists on some systems
+	actual, error := ConvertUnit("")
+	if error != nil {
+		t.Error(error)
+	}
+	if actual != jsh.B {
+		t.Errorf("Conversion error: expected %s, received %s", jsh.B.ToString(), actual.ToString())
+	}
+}
+
+func TestConvertBadUnit(t *testing.T) {
 	// Testing a bad unit conversion
 	actual, error := ConvertUnit("pB")
 	if error == nil {
 		t.Error("Expected an error for unit pB, received value of ", actual)
 	}
+
 }
 
 func TestParseGoodLine(t *testing.T) {