// Copyright 2023 The Gitea Authors. All rights reserved.// SPDX-License-Identifier: MIT package eval import (	"math"	"strings"	"testing" 	"github.com/stretchr/testify/assert"	"github.com/stretchr/testify/require") func tokens(s string) (a []any) {	for _, v := range strings.Fields(s) {		a = append(a, v)	}	return a} func TestEval(t *testing.T) {	n, err := Expr(0, "/", 0.0)	require.NoError(t, err)	assert.True(t, math.IsNaN(n.Value.(float64))) 	_, err = Expr(nil)	require.ErrorContains(t, err, "unsupported token type")	_, err = Expr([]string{})	require.ErrorContains(t, err, "unsupported token type")	_, err = Expr(struct{}{})	require.ErrorContains(t, err, "unsupported token type") 	cases := []struct {		expr string		want any	}{		{"-1", int64(-1)},		{"1 + 2", int64(3)},		{"3 - 2 + 4", int64(5)},		{"1 + 2 * 3", int64(7)},		{"1 + ( 2 * 3 )", int64(7)},		{"( 1 + 2 ) * 3", int64(9)},		{"( 1 + 2.0 ) / 3", float64(1)},		{"sum( 1 , 2 , 3 , 4 )", int64(10)},		{"100 + sum( 1 , 2 + 3 , 0.0 ) / 2", float64(103)},		{"100 * 5 / ( 5 + 15 )", int64(25)},		{"9 == 5", int64(0)},		{"5 == 5", int64(1)},		{"9 != 5", int64(1)},		{"5 != 5", int64(0)},		{"9 > 5", int64(1)},		{"5 > 9", int64(0)},		{"5 >= 9", int64(0)},		{"9 >= 9", int64(1)},		{"9 < 5", int64(0)},		{"5 < 9", int64(1)},		{"9 <= 5", int64(0)},		{"5 <= 5", int64(1)},		{"1 and 2", int64(1)}, // Golang template definition: non-zero values are all truth		{"1 and 0", int64(0)},		{"0 and 0", int64(0)},		{"1 or 2", int64(1)},		{"1 or 0", int64(1)},		{"0 or 1", int64(1)},		{"0 or 0", int64(0)},		{"not 2 == 1", int64(1)},		{"not not ( 9 < 5 )", int64(0)},	} 	for _, c := range cases {		n, err := Expr(tokens(c.expr)...)		require.NoError(t, err, "expr: %s", c.expr)		assert.Equal(t, c.want, n.Value)	} 	bads := []struct {		expr   string		errMsg string	}{		{"0 / 0", "integer divide by zero"},		{"1 +", "num stack is empty"},		{"+ 1", "num stack is empty"},		{"( 1", "incomplete sub-expression"},		{"1 )", "op stack is empty"}, // can not find the corresponding open bracket after the stack becomes empty		{"1 , 2", "expect 1 value as final result"},		{"( 1 , 2 )", "too many values in one bracket"},		{"1 a 2", "unknown operator"},	}	for _, c := range bads {		_, err = Expr(tokens(c.expr)...)		require.ErrorContains(t, err, c.errMsg, "expr: %s", c.expr)	}}