1// Copyright 2015 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5package big
6
7import (
8	"bytes"
9	"encoding/gob"
10	"encoding/json"
11	"io"
12	"testing"
13)
14
15var floatVals = []string{
16	"0",
17	"1",
18	"0.1",
19	"2.71828",
20	"1234567890",
21	"3.14e1234",
22	"3.14e-1234",
23	"0.738957395793475734757349579759957975985497e100",
24	"0.73895739579347546656564656573475734957975995797598589749859834759476745986795497e100",
25	"inf",
26	"Inf",
27}
28
29func TestFloatGobEncoding(t *testing.T) {
30	var medium bytes.Buffer
31	enc := gob.NewEncoder(&medium)
32	dec := gob.NewDecoder(&medium)
33	for _, test := range floatVals {
34		for _, sign := range []string{"", "+", "-"} {
35			for _, prec := range []uint{0, 1, 2, 10, 53, 64, 100, 1000} {
36				for _, mode := range []RoundingMode{ToNearestEven, ToNearestAway, ToZero, AwayFromZero, ToNegativeInf, ToPositiveInf} {
37					medium.Reset() // empty buffer for each test case (in case of failures)
38					x := sign + test
39
40					var tx Float
41					_, _, err := tx.SetPrec(prec).SetMode(mode).Parse(x, 0)
42					if err != nil {
43						t.Errorf("parsing of %s (%dbits, %v) failed (invalid test case): %v", x, prec, mode, err)
44						continue
45					}
46
47					// If tx was set to prec == 0, tx.Parse(x, 0) assumes precision 64. Correct it.
48					if prec == 0 {
49						tx.SetPrec(0)
50					}
51
52					if err := enc.Encode(&tx); err != nil {
53						t.Errorf("encoding of %v (%dbits, %v) failed: %v", &tx, prec, mode, err)
54						continue
55					}
56
57					var rx Float
58					if err := dec.Decode(&rx); err != nil {
59						t.Errorf("decoding of %v (%dbits, %v) failed: %v", &tx, prec, mode, err)
60						continue
61					}
62
63					if rx.Cmp(&tx) != 0 {
64						t.Errorf("transmission of %s failed: got %s want %s", x, rx.String(), tx.String())
65						continue
66					}
67
68					if rx.Prec() != prec {
69						t.Errorf("transmission of %s's prec failed: got %d want %d", x, rx.Prec(), prec)
70					}
71
72					if rx.Mode() != mode {
73						t.Errorf("transmission of %s's mode failed: got %s want %s", x, rx.Mode(), mode)
74					}
75
76					if rx.Acc() != tx.Acc() {
77						t.Errorf("transmission of %s's accuracy failed: got %s want %s", x, rx.Acc(), tx.Acc())
78					}
79				}
80			}
81		}
82	}
83}
84
85func TestFloatCorruptGob(t *testing.T) {
86	var buf bytes.Buffer
87	tx := NewFloat(4 / 3).SetPrec(1000).SetMode(ToPositiveInf)
88	if err := gob.NewEncoder(&buf).Encode(tx); err != nil {
89		t.Fatal(err)
90	}
91	b := buf.Bytes()
92
93	var rx Float
94	if err := gob.NewDecoder(bytes.NewReader(b)).Decode(&rx); err != nil {
95		t.Fatal(err)
96	}
97
98	if err := gob.NewDecoder(bytes.NewReader(b[:10])).Decode(&rx); err != io.ErrUnexpectedEOF {
99		t.Errorf("got %v want EOF", err)
100	}
101
102	b[1] = 0
103	if err := gob.NewDecoder(bytes.NewReader(b)).Decode(&rx); err == nil {
104		t.Fatal("got nil want version error")
105	}
106}
107
108func TestFloatJSONEncoding(t *testing.T) {
109	for _, test := range floatVals {
110		for _, sign := range []string{"", "+", "-"} {
111			for _, prec := range []uint{0, 1, 2, 10, 53, 64, 100, 1000} {
112				if prec > 53 && testing.Short() {
113					continue
114				}
115				x := sign + test
116				var tx Float
117				_, _, err := tx.SetPrec(prec).Parse(x, 0)
118				if err != nil {
119					t.Errorf("parsing of %s (prec = %d) failed (invalid test case): %v", x, prec, err)
120					continue
121				}
122				b, err := json.Marshal(&tx)
123				if err != nil {
124					t.Errorf("marshaling of %v (prec = %d) failed: %v", &tx, prec, err)
125					continue
126				}
127				var rx Float
128				rx.SetPrec(prec)
129				if err := json.Unmarshal(b, &rx); err != nil {
130					t.Errorf("unmarshaling of %v (prec = %d) failed: %v", &tx, prec, err)
131					continue
132				}
133				if rx.Cmp(&tx) != 0 {
134					t.Errorf("JSON encoding of %v (prec = %d) failed: got %v want %v", &tx, prec, &rx, &tx)
135				}
136			}
137		}
138	}
139}
140