added TestGoFunction() to test Go functions

t_funcs_test.go

@@ -68,3 +68,27 @@ func TestFunctionGetFunc(t *testing.T) {
 		t.Errorf(`(func() -> result = %v [%T], want = %v [%T]`, got, got, want, want)
 	}
 }
+
+func TestGoFunction(t *testing.T) {
+	section := "Funcs"
+	inputs := []inputType{
+		/*   1 */ {`myName()`, "Celestino Amoroso", nil},
+		/*   2 */ {`myName("Peppino")`, "Peppino", nil},
+	}
+
+	myName := func(ctx ExprContext, name string, args map[string]any) (result any, err error) {
+		var ok bool
+		if result, ok = args["name"].(string); !ok {
+			err = ErrWrongParamType(name, "name", TypeString, args["name"])
+		}
+		return
+	}
+
+	ctx := NewSimpleStore()
+	ctx.RegisterFunc("myName", NewGolangFunctor(myName), TypeString, []ExprFuncParam{
+		NewFuncParamFlagDef("name", PfOptional|PfDefault, "Celestino Amoroso"),
+	})
+
+	runCtxTestSuite(t, ctx, section, inputs)
+
+}