ratmarsh_test.go

Documentation: math/big

     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  
     5  package big
     6  
     7  import (
     8  	"bytes"
     9  	"encoding/gob"
    10  	"encoding/json"
    11  	"encoding/xml"
    12  	"testing"
    13  )
    14  
    15  func TestRatGobEncoding(t *testing.T) {
    16  	var medium bytes.Buffer
    17  	enc := gob.NewEncoder(&medium)
    18  	dec := gob.NewDecoder(&medium)
    19  	for _, test := range encodingTests {
    20  		medium.Reset() // empty buffer for each test case (in case of failures)
    21  		var tx Rat
    22  		tx.SetString(test + ".14159265")
    23  		if err := enc.Encode(&tx); err != nil {
    24  			t.Errorf("encoding of %s failed: %s", &tx, err)
    25  			continue
    26  		}
    27  		var rx Rat
    28  		if err := dec.Decode(&rx); err != nil {
    29  			t.Errorf("decoding of %s failed: %s", &tx, err)
    30  			continue
    31  		}
    32  		if rx.Cmp(&tx) != 0 {
    33  			t.Errorf("transmission of %s failed: got %s want %s", &tx, &rx, &tx)
    34  		}
    35  	}
    36  }
    37  
    38  // Sending a nil Rat pointer (inside a slice) on a round trip through gob should yield a zero.
    39  // TODO: top-level nils.
    40  func TestGobEncodingNilRatInSlice(t *testing.T) {
    41  	buf := new(bytes.Buffer)
    42  	enc := gob.NewEncoder(buf)
    43  	dec := gob.NewDecoder(buf)
    44  
    45  	var in = make([]*Rat, 1)
    46  	err := enc.Encode(&in)
    47  	if err != nil {
    48  		t.Errorf("gob encode failed: %q", err)
    49  	}
    50  	var out []*Rat
    51  	err = dec.Decode(&out)
    52  	if err != nil {
    53  		t.Fatalf("gob decode failed: %q", err)
    54  	}
    55  	if len(out) != 1 {
    56  		t.Fatalf("wrong len; want 1 got %d", len(out))
    57  	}
    58  	var zero Rat
    59  	if out[0].Cmp(&zero) != 0 {
    60  		t.Fatalf("transmission of (*Int)(nil) failed: got %s want 0", out)
    61  	}
    62  }
    63  
    64  var ratNums = []string{
    65  	"-141592653589793238462643383279502884197169399375105820974944592307816406286",
    66  	"-1415926535897932384626433832795028841971",
    67  	"-141592653589793",
    68  	"-1",
    69  	"0",
    70  	"1",
    71  	"141592653589793",
    72  	"1415926535897932384626433832795028841971",
    73  	"141592653589793238462643383279502884197169399375105820974944592307816406286",
    74  }
    75  
    76  var ratDenoms = []string{
    77  	"1",
    78  	"718281828459045",
    79  	"7182818284590452353602874713526624977572",
    80  	"718281828459045235360287471352662497757247093699959574966967627724076630353",
    81  }
    82  
    83  func TestRatJSONEncoding(t *testing.T) {
    84  	for _, num := range ratNums {
    85  		for _, denom := range ratDenoms {
    86  			var tx Rat
    87  			tx.SetString(num + "/" + denom)
    88  			b, err := json.Marshal(&tx)
    89  			if err != nil {
    90  				t.Errorf("marshaling of %s failed: %s", &tx, err)
    91  				continue
    92  			}
    93  			var rx Rat
    94  			if err := json.Unmarshal(b, &rx); err != nil {
    95  				t.Errorf("unmarshaling of %s failed: %s", &tx, err)
    96  				continue
    97  			}
    98  			if rx.Cmp(&tx) != 0 {
    99  				t.Errorf("JSON encoding of %s failed: got %s want %s", &tx, &rx, &tx)
   100  			}
   101  		}
   102  	}
   103  }
   104  
   105  func TestRatXMLEncoding(t *testing.T) {
   106  	for _, num := range ratNums {
   107  		for _, denom := range ratDenoms {
   108  			var tx Rat
   109  			tx.SetString(num + "/" + denom)
   110  			b, err := xml.Marshal(&tx)
   111  			if err != nil {
   112  				t.Errorf("marshaling of %s failed: %s", &tx, err)
   113  				continue
   114  			}
   115  			var rx Rat
   116  			if err := xml.Unmarshal(b, &rx); err != nil {
   117  				t.Errorf("unmarshaling of %s failed: %s", &tx, err)
   118  				continue
   119  			}
   120  			if rx.Cmp(&tx) != 0 {
   121  				t.Errorf("XML encoding of %s failed: got %s want %s", &tx, &rx, &tx)
   122  			}
   123  		}
   124  	}
   125  }
   126  
   127  func TestRatGobDecodeShortBuffer(t *testing.T) {
   128  	for _, tc := range [][]byte{
   129  		[]byte{0x2},
   130  		[]byte{0x2, 0x0, 0x0, 0x0, 0xff},
   131  		[]byte{0x2, 0xff, 0xff, 0xff, 0xff},
   132  	} {
   133  		err := NewRat(1, 2).GobDecode(tc)
   134  		if err == nil {
   135  			t.Error("expected GobDecode to return error for malformed input")
   136  		}
   137  	}
   138  }
   139
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