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decimal/decimal_test.go
Jason Biegel 4e5e2ed948 Remove insignificant digits during string parsing
2017-02-07 12:33:26 -05:00

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package decimal
import (
"encoding/json"
"encoding/xml"
"math"
"math/big"
"reflect"
"sort"
"strconv"
"strings"
"testing"
"time"
)
var testTable = map[float64]string{
3.141592653589793: "3.141592653589793",
3: "3",
1234567890123456: "1234567890123456",
1234567890123456000: "1234567890123456000",
1234.567890123456: "1234.567890123456",
.1234567890123456: "0.1234567890123456",
0: "0",
.1111111111111110: "0.111111111111111",
.1111111111111111: "0.1111111111111111",
.1111111111111119: "0.1111111111111119",
.000000000000000001: "0.000000000000000001",
.000000000000000002: "0.000000000000000002",
.000000000000000003: "0.000000000000000003",
.000000000000000005: "0.000000000000000005",
.000000000000000008: "0.000000000000000008",
.1000000000000001: "0.1000000000000001",
.1000000000000002: "0.1000000000000002",
.1000000000000003: "0.1000000000000003",
.1000000000000005: "0.1000000000000005",
.1000000000000008: "0.1000000000000008",
1e25: "10000000000000000000000000",
}
var testTableScientificNotation = map[string]string{
"1e9": "1000000000",
"2.41E-3": "0.00241",
"24.2E-4": "0.00242",
"243E-5": "0.00243",
"1e-5": "0.00001",
"245E3": "245000",
"1.2345E-1": "0.12345",
"0e5": "0",
"0e-5": "0",
"123.456e0": "123.456",
"123.456e2": "12345.6",
"123.456e10": "1234560000000",
}
func init() {
// add negatives
for f, s := range testTable {
if f > 0 {
testTable[-f] = "-" + s
}
}
for e, s := range testTableScientificNotation {
if string(e[0]) != "-" && s != "0" {
testTableScientificNotation["-"+e] = "-" + s
}
}
}
func TestNewFromFloat(t *testing.T) {
for f, s := range testTable {
d := NewFromFloat(f)
if d.String() != s {
t.Errorf("expected %s, got %s (%s, %d)",
s, d.String(),
d.value.String(), d.exp)
}
}
shouldPanicOn := []float64{
math.NaN(),
math.Inf(1),
math.Inf(-1),
}
for _, n := range shouldPanicOn {
var d Decimal
if !didPanic(func() { d = NewFromFloat(n) }) {
t.Fatalf("Expected panic when creating a Decimal from %v, got %v instead", n, d.String())
}
}
}
func TestNewFromString(t *testing.T) {
for _, s := range testTable {
d, err := NewFromString(s)
if err != nil {
t.Errorf("error while parsing %s", s)
} else if d.String() != s {
t.Errorf("expected %s, got %s (%s, %d)",
s, d.String(),
d.value.String(), d.exp)
}
}
for e, s := range testTableScientificNotation {
d, err := NewFromString(e)
if err != nil {
t.Errorf("error while parsing %s", e)
} else if d.String() != s {
t.Errorf("expected %s, got %s (%s, %d)",
s, d.String(),
d.value.String(), d.exp)
}
}
}
func TestNewFromStringErrs(t *testing.T) {
tests := []string{
"",
"qwert",
"-",
".",
"-.",
".-",
"234-.56",
"234-56",
"2-",
"..",
"2..",
"..2",
".5.2",
"8..2",
"8.1.",
"1e",
"1-e",
"1e9e",
"1ee9",
"1ee",
"1eE",
"1e-",
"1e-.",
"1e1.2",
"123.456e1.3",
"1e-1.2",
"123.456e-1.3",
"123.456Easdf",
"123.456e" + strconv.FormatInt(math.MinInt64, 10),
"123.456e" + strconv.FormatInt(math.MinInt32, 10),
}
for _, s := range tests {
_, err := NewFromString(s)
if err == nil {
t.Errorf("error expected when parsing %s", s)
}
}
}
func TestNewFromStringDeepEquals(t *testing.T) {
type StrCmp struct {
str1 string
str2 string
expected bool
}
tests := []StrCmp{
StrCmp{"1", "1", true},
StrCmp{"10", "10.0", true},
StrCmp{"1.1", "1.10", true},
StrCmp{"1.001", "1.01", false},
}
for _, cmp := range tests {
d1, err1 := NewFromString(cmp.str1)
d2, err2 := NewFromString(cmp.str2)
if err1 != nil || err2 != nil {
t.Errorf("error parsing strings to decimals")
}
if reflect.DeepEqual(d1, d2) != cmp.expected {
t.Errorf("comparison result is different from expected results for %s and %s",
cmp.str1, cmp.str2)
}
}
}
func TestNewFromFloatWithExponent(t *testing.T) {
type Inp struct {
float float64
exp int32
}
tests := map[Inp]string{
Inp{123.4, -3}: "123.4",
Inp{123.4, -1}: "123.4",
Inp{123.412345, 1}: "120",
Inp{123.412345, 0}: "123",
Inp{123.412345, -5}: "123.41235",
Inp{123.412345, -6}: "123.412345",
Inp{123.412345, -7}: "123.412345",
}
// add negatives
for p, s := range tests {
if p.float > 0 {
tests[Inp{-p.float, p.exp}] = "-" + s
}
}
for input, s := range tests {
d := NewFromFloatWithExponent(input.float, input.exp)
if d.String() != s {
t.Errorf("expected %s, got %s (%s, %d)",
s, d.String(),
d.value.String(), d.exp)
}
}
shouldPanicOn := []float64{
math.NaN(),
math.Inf(1),
math.Inf(-1),
}
for _, n := range shouldPanicOn {
var d Decimal
if !didPanic(func() { d = NewFromFloatWithExponent(n, 0) }) {
t.Fatalf("Expected panic when creating a Decimal from %v, got %v instead", n, d.String())
}
}
}
func TestJSON(t *testing.T) {
for _, s := range testTable {
var doc struct {
Amount Decimal `json:"amount"`
}
docStr := `{"amount":"` + s + `"}`
docStrNumber := `{"amount":` + s + `}`
err := json.Unmarshal([]byte(docStr), &doc)
if err != nil {
t.Errorf("error unmarshaling %s: %v", docStr, err)
} else if doc.Amount.String() != s {
t.Errorf("expected %s, got %s (%s, %d)",
s, doc.Amount.String(),
doc.Amount.value.String(), doc.Amount.exp)
}
out, err := json.Marshal(&doc)
if err != nil {
t.Errorf("error marshaling %+v: %v", doc, err)
} else if string(out) != docStr {
t.Errorf("expected %s, got %s", docStr, string(out))
}
// make sure unquoted marshalling works too
MarshalJSONWithoutQuotes = true
out, err = json.Marshal(&doc)
if err != nil {
t.Errorf("error marshaling %+v: %v", doc, err)
} else if string(out) != docStrNumber {
t.Errorf("expected %s, got %s", docStrNumber, string(out))
}
MarshalJSONWithoutQuotes = false
}
}
func TestBadJSON(t *testing.T) {
for _, testCase := range []string{
"]o_o[",
"{",
`{"amount":""`,
`{"amount":""}`,
`{"amount":"nope"}`,
`0.333`,
} {
var doc struct {
Amount Decimal `json:"amount"`
}
err := json.Unmarshal([]byte(testCase), &doc)
if err == nil {
t.Errorf("expected error, got %+v", doc)
}
}
}
func TestXML(t *testing.T) {
for _, s := range testTable {
var doc struct {
XMLName xml.Name `xml:"account"`
Amount Decimal `xml:"amount"`
}
docStr := `<account><amount>` + s + `</amount></account>`
err := xml.Unmarshal([]byte(docStr), &doc)
if err != nil {
t.Errorf("error unmarshaling %s: %v", docStr, err)
} else if doc.Amount.String() != s {
t.Errorf("expected %s, got %s (%s, %d)",
s, doc.Amount.String(),
doc.Amount.value.String(), doc.Amount.exp)
}
out, err := xml.Marshal(&doc)
if err != nil {
t.Errorf("error marshaling %+v: %v", doc, err)
} else if string(out) != docStr {
t.Errorf("expected %s, got %s", docStr, string(out))
}
}
}
func TestBadXML(t *testing.T) {
for _, testCase := range []string{
"o_o",
"<abc",
"<account><amount>7",
`<html><body></body></html>`,
`<account><amount></amount></account>`,
`<account><amount>nope</amount></account>`,
`0.333`,
} {
var doc struct {
XMLName xml.Name `xml:"account"`
Amount Decimal `xml:"amount"`
}
err := xml.Unmarshal([]byte(testCase), &doc)
if err == nil {
t.Errorf("expected error, got %+v", doc)
}
}
}
func TestDecimal_rescale(t *testing.T) {
type Inp struct {
int int64
exp int32
rescale int32
}
tests := map[Inp]string{
Inp{1234, -3, -5}: "1.234",
Inp{1234, -3, 0}: "1",
Inp{1234, 3, 0}: "1234000",
Inp{1234, -4, -4}: "0.1234",
}
// add negatives
for p, s := range tests {
if p.int > 0 {
tests[Inp{-p.int, p.exp, p.rescale}] = "-" + s
}
}
for input, s := range tests {
d := New(input.int, input.exp).rescale(input.rescale)
if d.String() != s {
t.Errorf("expected %s, got %s (%s, %d)",
s, d.String(),
d.value.String(), d.exp)
}
// test StringScaled
s2 := New(input.int, input.exp).StringScaled(input.rescale)
if s2 != s {
t.Errorf("expected %s, got %s", s, s2)
}
}
}
func TestDecimal_Floor(t *testing.T) {
type testData struct {
input string
expected string
}
tests := []testData{
{"1.999", "1"},
{"1", "1"},
{"1.01", "1"},
{"0", "0"},
{"0.9", "0"},
{"0.1", "0"},
{"-0.9", "-1"},
{"-0.1", "-1"},
{"-1.00", "-1"},
{"-1.01", "-2"},
{"-1.999", "-2"},
}
for _, test := range tests {
d, _ := NewFromString(test.input)
expected, _ := NewFromString(test.expected)
got := d.Floor()
if !got.Equal(expected) {
t.Errorf("Floor(%s): got %s, expected %s", d, got, expected)
}
}
}
func TestDecimal_Ceil(t *testing.T) {
type testData struct {
input string
expected string
}
tests := []testData{
{"1.999", "2"},
{"1", "1"},
{"1.01", "2"},
{"0", "0"},
{"0.9", "1"},
{"0.1", "1"},
{"-0.9", "0"},
{"-0.1", "0"},
{"-1.00", "-1"},
{"-1.01", "-1"},
{"-1.999", "-1"},
}
for _, test := range tests {
d, _ := NewFromString(test.input)
expected, _ := NewFromString(test.expected)
got := d.Ceil()
if !got.Equal(expected) {
t.Errorf("Ceil(%s): got %s, expected %s", d, got, expected)
}
}
}
func TestDecimal_RoundAndStringFixed(t *testing.T) {
type testData struct {
input string
places int32
expected string
expectedFixed string
}
tests := []testData{
{"1.454", 0, "1", ""},
{"1.454", 1, "1.5", ""},
{"1.454", 2, "1.45", ""},
{"1.454", 3, "1.454", ""},
{"1.454", 4, "1.454", "1.4540"},
{"1.454", 5, "1.454", "1.45400"},
{"1.554", 0, "2", ""},
{"1.554", 1, "1.6", ""},
{"1.554", 2, "1.55", ""},
{"0.554", 0, "1", ""},
{"0.454", 0, "0", ""},
{"0.454", 5, "0.454", "0.45400"},
{"0", 0, "0", ""},
{"0", 1, "0", "0.0"},
{"0", 2, "0", "0.00"},
{"0", -1, "0", ""},
{"5", 2, "5", "5.00"},
{"5", 1, "5", "5.0"},
{"5", 0, "5", ""},
{"500", 2, "500", "500.00"},
{"545", -1, "550", ""},
{"545", -2, "500", ""},
{"545", -3, "1000", ""},
{"545", -4, "0", ""},
{"499", -3, "0", ""},
{"499", -4, "0", ""},
}
// add negative number tests
for _, test := range tests {
expected := test.expected
if expected != "0" {
expected = "-" + expected
}
expectedStr := test.expectedFixed
if strings.ContainsAny(expectedStr, "123456789") && expectedStr != "" {
expectedStr = "-" + expectedStr
}
tests = append(tests,
testData{"-" + test.input, test.places, expected, expectedStr})
}
for _, test := range tests {
d, err := NewFromString(test.input)
if err != nil {
panic(err)
}
// test Round
expected, err := NewFromString(test.expected)
if err != nil {
panic(err)
}
got := d.Round(test.places)
if !got.Equal(expected) {
t.Errorf("Rounding %s to %d places, got %s, expected %s",
d, test.places, got, expected)
}
// test StringFixed
if test.expectedFixed == "" {
test.expectedFixed = test.expected
}
gotStr := d.StringFixed(test.places)
if gotStr != test.expectedFixed {
t.Errorf("(%s).StringFixed(%d): got %s, expected %s",
d, test.places, gotStr, test.expectedFixed)
}
}
}
func TestDecimal_Uninitialized(t *testing.T) {
a := Decimal{}
b := Decimal{}
decs := []Decimal{
a,
a.rescale(10),
a.Abs(),
a.Add(b),
a.Sub(b),
a.Mul(b),
a.Div(New(1, -1)),
a.Round(2),
a.Floor(),
a.Ceil(),
a.Truncate(2),
}
for _, d := range decs {
if d.String() != "0" {
t.Errorf("expected 0, got %s", d.String())
}
if d.StringFixed(3) != "0.000" {
t.Errorf("expected 0, got %s", d.StringFixed(3))
}
if d.StringScaled(-2) != "0" {
t.Errorf("expected 0, got %s", d.StringScaled(-2))
}
}
if a.Cmp(b) != 0 {
t.Errorf("a != b")
}
if a.Exponent() != 0 {
t.Errorf("a.Exponent() != 0")
}
if a.IntPart() != 0 {
t.Errorf("a.IntPar() != 0")
}
f, _ := a.Float64()
if f != 0 {
t.Errorf("a.Float64() != 0")
}
if a.Rat().RatString() != "0" {
t.Errorf("a.Rat() != 0, got %s", a.Rat().RatString())
}
}
func TestDecimal_Add(t *testing.T) {
type Inp struct {
a string
b string
}
inputs := map[Inp]string{
Inp{"2", "3"}: "5",
Inp{"2454495034", "3451204593"}: "5905699627",
Inp{"24544.95034", ".3451204593"}: "24545.2954604593",
Inp{".1", ".1"}: "0.2",
Inp{".1", "-.1"}: "0",
Inp{"0", "1.001"}: "1.001",
}
for inp, res := range inputs {
a, err := NewFromString(inp.a)
if err != nil {
t.FailNow()
}
b, err := NewFromString(inp.b)
if err != nil {
t.FailNow()
}
c := a.Add(b)
if c.String() != res {
t.Errorf("expected %s, got %s", res, c.String())
}
}
}
func TestDecimal_Sub(t *testing.T) {
type Inp struct {
a string
b string
}
inputs := map[Inp]string{
Inp{"2", "3"}: "-1",
Inp{"12", "3"}: "9",
Inp{"-2", "9"}: "-11",
Inp{"2454495034", "3451204593"}: "-996709559",
Inp{"24544.95034", ".3451204593"}: "24544.6052195407",
Inp{".1", "-.1"}: "0.2",
Inp{".1", ".1"}: "0",
Inp{"0", "1.001"}: "-1.001",
Inp{"1.001", "0"}: "1.001",
Inp{"2.3", ".3"}: "2",
}
for inp, res := range inputs {
a, err := NewFromString(inp.a)
if err != nil {
t.FailNow()
}
b, err := NewFromString(inp.b)
if err != nil {
t.FailNow()
}
c := a.Sub(b)
if c.String() != res {
t.Errorf("expected %s, got %s", res, c.String())
}
}
}
func TestDecimal_Mul(t *testing.T) {
type Inp struct {
a string
b string
}
inputs := map[Inp]string{
Inp{"2", "3"}: "6",
Inp{"2454495034", "3451204593"}: "8470964534836491162",
Inp{"24544.95034", ".3451204593"}: "8470.964534836491162",
Inp{".1", ".1"}: "0.01",
Inp{"0", "1.001"}: "0",
}
for inp, res := range inputs {
a, err := NewFromString(inp.a)
if err != nil {
t.FailNow()
}
b, err := NewFromString(inp.b)
if err != nil {
t.FailNow()
}
c := a.Mul(b)
if c.String() != res {
t.Errorf("expected %s, got %s", res, c.String())
}
}
// positive scale
c := New(1234, 5).Mul(New(45, -1))
if c.String() != "555300000" {
t.Errorf("Expected %s, got %s", "555300000", c.String())
}
}
func TestDecimal_Div(t *testing.T) {
type Inp struct {
a string
b string
}
inputs := map[Inp]string{
Inp{"6", "3"}: "2",
Inp{"10", "2"}: "5",
Inp{"2.2", "1.1"}: "2",
Inp{"-2.2", "-1.1"}: "2",
Inp{"12.88", "5.6"}: "2.3",
Inp{"1023427554493", "43432632"}: "23563.5628642767953828", // rounded
Inp{"1", "434324545566634"}: "0.0000000000000023",
Inp{"1", "3"}: "0.3333333333333333",
Inp{"2", "3"}: "0.6666666666666667", // rounded
Inp{"10000", "3"}: "3333.3333333333333333",
Inp{"10234274355545544493", "-3"}: "-3411424785181848164.3333333333333333",
Inp{"-4612301402398.4753343454", "23.5"}: "-196268144782.9138440146978723",
}
for inp, expectedStr := range inputs {
num, err := NewFromString(inp.a)
if err != nil {
t.FailNow()
}
denom, err := NewFromString(inp.b)
if err != nil {
t.FailNow()
}
got := num.Div(denom)
expected, _ := NewFromString(expectedStr)
if !got.Equal(expected) {
t.Errorf("expected %v when dividing %v by %v, got %v",
expected, num, denom, got)
}
got2 := num.DivRound(denom, int32(DivisionPrecision))
if !got2.Equal(expected) {
t.Errorf("expected %v on DivRound (%v,%v), got %v", expected, num, denom, got2)
}
}
type Inp2 struct {
n int64
exp int32
n2 int64
exp2 int32
}
// test code path where exp > 0
inputs2 := map[Inp2]string{
Inp2{124, 10, 3, 1}: "41333333333.3333333333333333",
Inp2{124, 10, 3, 0}: "413333333333.3333333333333333",
Inp2{124, 10, 6, 1}: "20666666666.6666666666666667",
Inp2{124, 10, 6, 0}: "206666666666.6666666666666667",
Inp2{10, 10, 10, 1}: "1000000000",
}
for inp, expectedAbs := range inputs2 {
for i := -1; i <= 1; i += 2 {
for j := -1; j <= 1; j += 2 {
n := inp.n * int64(i)
n2 := inp.n2 * int64(j)
num := New(n, inp.exp)
denom := New(n2, inp.exp2)
expected := expectedAbs
if i != j {
expected = "-" + expectedAbs
}
got := num.Div(denom)
if got.String() != expected {
t.Errorf("expected %s when dividing %v by %v, got %v",
expected, num, denom, got)
}
}
}
}
}
func TestDecimal_QuoRem(t *testing.T) {
type Inp4 struct {
d string
d2 string
exp int32
q string
r string
}
cases := []Inp4{
Inp4{"10", "1", 0, "10", "0"},
Inp4{"1", "10", 0, "0", "1"},
Inp4{"1", "4", 2, "0.25", "0"},
Inp4{"1", "8", 2, "0.12", "0.04"},
Inp4{"10", "3", 1, "3.3", "0.1"},
Inp4{"100", "3", 1, "33.3", "0.1"},
Inp4{"1000", "10", -3, "0", "1000"},
Inp4{"1e-3", "2e-5", 0, "50", "0"},
Inp4{"1e-3", "2e-3", 1, "0.5", "0"},
Inp4{"4e-3", "0.8", 4, "5e-3", "0"},
Inp4{"4.1e-3", "0.8", 3, "5e-3", "1e-4"},
Inp4{"-4", "-3", 0, "1", "-1"},
Inp4{"-4", "3", 0, "-1", "-1"},
}
for _, inp4 := range cases {
d, _ := NewFromString(inp4.d)
d2, _ := NewFromString(inp4.d2)
prec := inp4.exp
q, r := d.QuoRem(d2, prec)
expectedQ, _ := NewFromString(inp4.q)
expectedR, _ := NewFromString(inp4.r)
if !q.Equal(expectedQ) || !r.Equal(expectedR) {
t.Errorf("bad QuoRem division %s , %s , %d got %v, %v expected %s , %s",
inp4.d, inp4.d2, prec, q, r, inp4.q, inp4.r)
}
if !d.Equal(d2.Mul(q).Add(r)) {
t.Errorf("not fitting: d=%v, d2= %v, prec=%d, q=%v, r=%v",
d, d2, prec, q, r)
}
if !q.Equal(q.Truncate(prec)) {
t.Errorf("quotient wrong precision: d=%v, d2= %v, prec=%d, q=%v, r=%v",
d, d2, prec, q, r)
}
if r.Abs().Cmp(d2.Abs().Mul(New(1, -prec))) >= 0 {
t.Errorf("remainder too large: d=%v, d2= %v, prec=%d, q=%v, r=%v",
d, d2, prec, q, r)
}
if r.value.Sign()*d.value.Sign() < 0 {
t.Errorf("signum of divisor and rest do not match: d=%v, d2= %v, prec=%d, q=%v, r=%v",
d, d2, prec, q, r)
}
}
}
type DivTestCase struct {
d Decimal
d2 Decimal
prec int32
}
func createDivTestCases() []DivTestCase {
res := make([]DivTestCase, 0)
var n int32 = 5
a := []int{1, 2, 3, 6, 7, 10, 100, 14, 5, 400, 0, 1000000, 1000000 + 1, 1000000 - 1}
for s := -1; s < 2; s = s + 2 { // 2
for s2 := -1; s2 < 2; s2 = s2 + 2 { // 2
for e1 := -n; e1 <= n; e1++ { // 2n+1
for e2 := -n; e2 <= n; e2++ { // 2n+1
var prec int32
for prec = -n; prec <= n; prec++ { // 2n+1
for _, v1 := range a { // 11
for _, v2 := range a { // 11, even if 0 is skipped
sign1 := New(int64(s), 0)
sign2 := New(int64(s2), 0)
d := sign1.Mul(New(int64(v1), int32(e1)))
d2 := sign2.Mul(New(int64(v2), int32(e2)))
res = append(res, DivTestCase{d, d2, prec})
}
}
}
}
}
}
}
return res
}
func TestDecimal_QuoRem2(t *testing.T) {
for _, tc := range createDivTestCases() {
d := tc.d
if sign(tc.d2) == 0 {
continue
}
d2 := tc.d2
prec := tc.prec
q, r := d.QuoRem(d2, prec)
// rule 1: d = d2*q +r
if !d.Equal(d2.Mul(q).Add(r)) {
t.Errorf("not fitting, d=%v, d2=%v, prec=%d, q=%v, r=%v",
d, d2, prec, q, r)
}
// rule 2: q is integral multiple of 10^(-prec)
if !q.Equal(q.Truncate(prec)) {
t.Errorf("quotient wrong precision, d=%v, d2=%v, prec=%d, q=%v, r=%v",
d, d2, prec, q, r)
}
// rule 3: abs(r)<abs(d) * 10^(-prec)
if r.Abs().Cmp(d2.Abs().Mul(New(1, -prec))) >= 0 {
t.Errorf("remainder too large, d=%v, d2=%v, prec=%d, q=%v, r=%v",
d, d2, prec, q, r)
}
// rule 4: r and d have the same sign
if r.value.Sign()*d.value.Sign() < 0 {
t.Errorf("signum of divisor and rest do not match, "+
"d=%v, d2=%v, prec=%d, q=%v, r=%v",
d, d2, prec, q, r)
}
}
}
// this is the old Div method from decimal
// Div returns d / d2. If it doesn't divide exactly, the result will have
// DivisionPrecision digits after the decimal point.
func (d Decimal) DivOld(d2 Decimal, prec int) Decimal {
// NOTE(vadim): division is hard, use Rat to do it
ratNum := d.Rat()
ratDenom := d2.Rat()
quoRat := big.NewRat(0, 1).Quo(ratNum, ratDenom)
// HACK(vadim): converting from Rat to Decimal inefficiently for now
ret, err := NewFromString(quoRat.FloatString(prec))
if err != nil {
panic(err) // this should never happen
}
return ret
}
func Benchmark_DivideOriginal(b *testing.B) {
tcs := createDivTestCases()
b.ResetTimer()
for i := 0; i < b.N; i++ {
for _, tc := range tcs {
d := tc.d
if sign(tc.d2) == 0 {
continue
}
d2 := tc.d2
prec := tc.prec
a := d.DivOld(d2, int(prec))
if sign(a) > 2 {
panic("dummy panic")
}
}
}
}
func Benchmark_DivideNew(b *testing.B) {
tcs := createDivTestCases()
b.ResetTimer()
for i := 0; i < b.N; i++ {
for _, tc := range tcs {
d := tc.d
if sign(tc.d2) == 0 {
continue
}
d2 := tc.d2
prec := tc.prec
a := d.DivRound(d2, prec)
if sign(a) > 2 {
panic("dummy panic")
}
}
}
}
func sign(d Decimal) int {
return d.value.Sign()
}
// rules for rounded divide, rounded to integer
// rounded_divide(d,d2) = q
// sign q * sign (d/d2) >= 0
// for d and d2 >0 :
// q is already rounded
// q = d/d2 + r , with r > -0.5 and r <= 0.5
// thus q-d/d2 = r, with r > -0.5 and r <= 0.5
// and d2 q -d = r d2 with r d2 > -d2/2 and r d2 <= d2/2
// and 2 (d2 q -d) = x with x > -d2 and x <= d2
// if we factor in precision then x > -d2 * 10^(-precision) and x <= d2 * 10(-precision)
func TestDecimal_DivRound(t *testing.T) {
cases := []struct {
d string
d2 string
prec int32
result string
}{
{"2", "2", 0, "1"},
{"1", "2", 0, "1"},
{"-1", "2", 0, "-1"},
{"-1", "-2", 0, "1"},
{"1", "-2", 0, "-1"},
{"1", "-20", 1, "-0.1"},
{"1", "-20", 2, "-0.05"},
{"1", "20.0000000000000000001", 1, "0"},
{"1", "19.9999999999999999999", 1, "0.1"},
}
for _, s := range cases {
d, _ := NewFromString(s.d)
d2, _ := NewFromString(s.d2)
result, _ := NewFromString(s.result)
prec := s.prec
q := d.DivRound(d2, prec)
if sign(q)*sign(d)*sign(d2) < 0 {
t.Errorf("sign of quotient wrong, got: %v/%v is about %v", d, d2, q)
}
x := q.Mul(d2).Abs().Sub(d.Abs()).Mul(New(2, 0))
if x.Cmp(d2.Abs().Mul(New(1, -prec))) > 0 {
t.Errorf("wrong rounding, got: %v/%v prec=%d is about %v", d, d2, prec, q)
}
if x.Cmp(d2.Abs().Mul(New(-1, -prec))) <= 0 {
t.Errorf("wrong rounding, got: %v/%v prec=%d is about %v", d, d2, prec, q)
}
if !q.Equal(result) {
t.Errorf("rounded division wrong %s / %s scale %d = %s, got %v", s.d, s.d2, prec, s.result, q)
}
}
}
func TestDecimal_DivRound2(t *testing.T) {
for _, tc := range createDivTestCases() {
d := tc.d
if sign(tc.d2) == 0 {
continue
}
d2 := tc.d2
prec := tc.prec
q := d.DivRound(d2, prec)
if sign(q)*sign(d)*sign(d2) < 0 {
t.Errorf("sign of quotient wrong, got: %v/%v is about %v", d, d2, q)
}
x := q.Mul(d2).Abs().Sub(d.Abs()).Mul(New(2, 0))
if x.Cmp(d2.Abs().Mul(New(1, -prec))) > 0 {
t.Errorf("wrong rounding, got: %v/%v prec=%d is about %v", d, d2, prec, q)
}
if x.Cmp(d2.Abs().Mul(New(-1, -prec))) <= 0 {
t.Errorf("wrong rounding, got: %v/%v prec=%d is about %v", d, d2, prec, q)
}
}
}
func TestDecimal_Mod(t *testing.T) {
type Inp struct {
a string
b string
}
inputs := map[Inp]string{
Inp{"3", "2"}: "1",
Inp{"3451204593", "2454495034"}: "996709559",
Inp{"24544.95034", ".3451204593"}: "0.3283950433",
Inp{".1", ".1"}: "0",
Inp{"0", "1.001"}: "0",
Inp{"-7.5", "2"}: "-1.5",
Inp{"7.5", "-2"}: "1.5",
Inp{"-7.5", "-2"}: "-1.5",
}
for inp, res := range inputs {
a, err := NewFromString(inp.a)
if err != nil {
t.FailNow()
}
b, err := NewFromString(inp.b)
if err != nil {
t.FailNow()
}
c := a.Mod(b)
if c.String() != res {
t.Errorf("expected %s, got %s", res, c.String())
}
}
}
func TestDecimal_Overflow(t *testing.T) {
if !didPanic(func() { New(1, math.MinInt32).Mul(New(1, math.MinInt32)) }) {
t.Fatalf("should have gotten an overflow panic")
}
if !didPanic(func() { New(1, math.MaxInt32).Mul(New(1, math.MaxInt32)) }) {
t.Fatalf("should have gotten an overflow panic")
}
}
func TestDecimal_ExtremeValues(t *testing.T) {
// NOTE(vadim): this test takes pretty much forever
if testing.Short() {
t.Skip()
}
// NOTE(vadim): Seriously, the numbers involved are so large that this
// test will take way too long, so mark it as success if it takes over
// 1 second. The way this test typically fails (integer overflow) is that
// a wrong result appears quickly, so if it takes a long time then it is
// probably working properly.
// Why even bother testing this? Completeness, I guess. -Vadim
const timeLimit = 1 * time.Second
test := func(f func()) {
c := make(chan bool)
go func() {
f()
close(c)
}()
select {
case <-c:
case <-time.After(timeLimit):
}
}
test(func() {
got := New(123, math.MinInt32).Floor()
if !got.Equal(NewFromFloat(0)) {
t.Errorf("Error: got %s, expected 0", got)
}
})
test(func() {
got := New(123, math.MinInt32).Ceil()
if !got.Equal(NewFromFloat(1)) {
t.Errorf("Error: got %s, expected 1", got)
}
})
test(func() {
got := New(123, math.MinInt32).Rat().FloatString(10)
expected := "0.0000000000"
if got != expected {
t.Errorf("Error: got %s, expected %s", got, expected)
}
})
}
func TestIntPart(t *testing.T) {
for _, testCase := range []struct {
Dec string
IntPart int64
}{
{"0.01", 0},
{"12.1", 12},
{"9999.999", 9999},
{"-32768.01234", -32768},
} {
d, err := NewFromString(testCase.Dec)
if err != nil {
t.Fatal(err)
}
if d.IntPart() != testCase.IntPart {
t.Errorf("expect %d, got %d", testCase.IntPart, d.IntPart())
}
}
}
func TestDecimal_Min(t *testing.T) {
// the first element in the array is the expected answer, rest are inputs
testCases := [][]float64{
{0, 0},
{1, 1},
{-1, -1},
{1, 1, 2},
{-2, 1, 2, -2},
{-3, 0, 2, -2, -3},
}
for _, test := range testCases {
expected, input := test[0], test[1:]
expectedDecimal := NewFromFloat(expected)
decimalInput := []Decimal{}
for _, inp := range input {
d := NewFromFloat(inp)
decimalInput = append(decimalInput, d)
}
got := Min(decimalInput[0], decimalInput[1:]...)
if !got.Equal(expectedDecimal) {
t.Errorf("Expected %v, got %v, input=%+v", expectedDecimal, got,
decimalInput)
}
}
}
func TestDecimal_Max(t *testing.T) {
// the first element in the array is the expected answer, rest are inputs
testCases := [][]float64{
{0, 0},
{1, 1},
{-1, -1},
{2, 1, 2},
{2, 1, 2, -2},
{3, 0, 3, -2},
{-2, -3, -2},
}
for _, test := range testCases {
expected, input := test[0], test[1:]
expectedDecimal := NewFromFloat(expected)
decimalInput := []Decimal{}
for _, inp := range input {
d := NewFromFloat(inp)
decimalInput = append(decimalInput, d)
}
got := Max(decimalInput[0], decimalInput[1:]...)
if !got.Equal(expectedDecimal) {
t.Errorf("Expected %v, got %v, input=%+v", expectedDecimal, got,
decimalInput)
}
}
}
func TestDecimal_Scan(t *testing.T) {
// test the Scan method that implements the
// sql.Scanner interface
// check for the for different type of values
// that are possible to be received from the database
// drivers
// in normal operations the db driver (sqlite at least)
// will return an int64 if you specified a numeric format
a := Decimal{}
dbvalue := float64(54.33)
expected := NewFromFloat(dbvalue)
err := a.Scan(dbvalue)
if err != nil {
// Scan failed... no need to test result value
t.Errorf("a.Scan(54.33) failed with message: %s", err)
} else {
// Scan succeeded... test resulting values
if !a.Equal(expected) {
t.Errorf("%s does not equal to %s", a, expected)
}
}
// at least SQLite returns an int64 when 0 is stored in the db
// and you specified a numeric format on the schema
dbvalue_int := int64(0)
expected = New(dbvalue_int, 0)
err = a.Scan(dbvalue_int)
if err != nil {
// Scan failed... no need to test result value
t.Errorf("a.Scan(0) failed with message: %s", err)
} else {
// Scan succeeded... test resulting values
if !a.Equal(expected) {
t.Errorf("%s does not equal to %s", a, expected)
}
}
// in case you specified a varchar in your SQL schema,
// the database driver will return byte slice []byte
value_str := "535.666"
dbvalue_str := []byte(value_str)
expected, err = NewFromString(value_str)
if err != nil {
t.Fatal(err)
}
err = a.Scan(dbvalue_str)
if err != nil {
// Scan failed... no need to test result value
t.Errorf("a.Scan('535.666') failed with message: %s", err)
} else {
// Scan succeeded... test resulting values
if !a.Equal(expected) {
t.Errorf("%s does not equal to %s", a, expected)
}
}
// lib/pq can also return strings
expected, err = NewFromString(value_str)
if err != nil {
t.Fatal(err)
}
err = a.Scan(value_str)
if err != nil {
// Scan failed... no need to test result value
t.Errorf("a.Scan('535.666') failed with message: %s", err)
} else {
// Scan succeeded... test resulting values
if !a.Equal(expected) {
t.Errorf("%s does not equal to %s", a, expected)
}
}
}
func TestDecimal_Value(t *testing.T) {
// check that nil is handled appropriately
var decimalPtr *Decimal
value, err := decimalPtr.Value()
if err != nil {
t.Errorf("(*Decimal)(<nil>).Value() failed with message: %s", err)
} else if value != nil {
t.Errorf("%v is not nil", value)
}
// check that normal case is handled appropriately
a := New(1234, -2)
expected := "12.34"
value, err = a.Value()
if err != nil {
t.Errorf("Decimal(12.34).Value() failed with message: %s", err)
} else if value.(string) != expected {
t.Errorf("%s does not equal to %s", a, expected)
}
}
// old tests after this line
func TestDecimal_Scale(t *testing.T) {
a := New(1234, -3)
if a.Exponent() != -3 {
t.Errorf("error")
}
}
func TestDecimal_Abs1(t *testing.T) {
a := New(-1234, -4)
b := New(1234, -4)
c := a.Abs()
if c.Cmp(b) != 0 {
t.Errorf("error")
}
}
func TestDecimal_Abs2(t *testing.T) {
a := New(-1234, -4)
b := New(1234, -4)
c := b.Abs()
if c.Cmp(a) == 0 {
t.Errorf("error")
}
}
func TestDecimal_Equal(t *testing.T) {
a := New(1234, 3)
b := New(1234, 3)
if !a.Equal(b) {
t.Errorf("%q should equal %q", a, b)
}
}
func TestDecimal_ScalesNotEqual(t *testing.T) {
a := New(1234, 2)
b := New(1234, 3)
if a.Equal(b) {
t.Errorf("%q should not equal %q", a, b)
}
}
func TestDecimal_Cmp1(t *testing.T) {
a := New(123, 3)
b := New(-1234, 2)
if a.Cmp(b) != 1 {
t.Errorf("Error")
}
}
func TestDecimal_Cmp2(t *testing.T) {
a := New(123, 3)
b := New(1234, 2)
if a.Cmp(b) != -1 {
t.Errorf("Error")
}
}
func TestPow(t *testing.T) {
a := New(4, 0)
b := New(2, 0)
x := a.Pow(b)
if x.String() != "16" {
t.Errorf("Error, saw %s", x.String())
}
}
func didPanic(f func()) bool {
ret := false
func() {
defer func() {
if message := recover(); message != nil {
ret = true
}
}()
// call the target function
f()
}()
return ret
}
type DecimalSlice []Decimal
func (p DecimalSlice) Len() int { return len(p) }
func (p DecimalSlice) Swap(i, j int) { p[i], p[j] = p[j], p[i] }
func (p DecimalSlice) Less(i, j int) bool { return p[i].Cmp(p[j]) < 0 }
func Benchmark_Cmp(b *testing.B) {
decimals := DecimalSlice([]Decimal{})
for i := 0; i < 1000000; i++ {
decimals = append(decimals, New(int64(i), 0))
}
b.ResetTimer()
for i := 0; i < b.N; i++ {
sort.Sort(decimals)
}
}
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