eval_test.go

package eval

import "testing"

func TestAlgo(t *testing.T) {
	// whitespace is ignored
	tests := map[string]int{
		"2 + 2":                     4,
		"10 * 2":                    20,
		"5 + 10 * 2":                25,
		"100 + 200 + 300 + 400":     1000,
		"8 * 1024":                  8192,
		"4 * 1024 + 1024":           5120,
		"1024 + 1024 + 1024 + 1024": 4096,
		"2 - 2":                     0,
		"4 - 2 + 2":                 4,
		"100":                       100,
		"4 / 2":                     2,
		"( 100 + 200 ) * 2":         600,
		"(100 + 200) * 2":           600,
		"(100 + 200) + (100 + 200)": 600,
		"100 / 100":                 1,
		"100/100":                   1,
		"20 - 10 * 2":               0,
		"2 * (100 + 100)":           400,
		"2+2":                       4,
		"100+100":                   200,
		"100+100*2":                 300,
		"(4/2) + (4/2)":             4,
		"(4/2) -(4*2)":              -6,
		"(4+2*4)+ (4/2)":            14,
		"(0-1)*2":                   -2, // parser does not support negative numbers, yet
	}

	for expression, result := range tests {
		exp, err := rpn(expression)
		if err != nil {
			t.Fatal(err)
		}
		v, err := eval(exp)
		if err != nil {
			t.Fatal(err)
		}
		if v != result {
			t.Errorf("expected %d but got %d", result, v)
		}
	}
}