memio - buffer_test.go

     1  package memio
     2  
     3  import (
     4  	"bytes"
     5  	"io"
     6  	"testing"
     7  )
     8  
     9  var (
    10  	_ io.Reader   = &Buffer{}
    11  	_ io.Writer   = &Buffer{}
    12  	_ io.WriterTo = &Buffer{}
    13  	_ io.ReaderAt = &Buffer{}
    14  	_ io.WriterAt = &Buffer{}
    15  )
    16  
    17  func TestBufferRead(t *testing.T) {
    18  	reader := Buffer("Hello, World!")
    19  	toRead := make([]byte, 5)
    20  	if n, err := reader.Read(toRead); n != 5 {
    21  		t.Errorf("expecting to read 5 bytes, read %d", n)
    22  		return
    23  	} else if err != nil {
    24  		t.Errorf("got error: %q", err.Error())
    25  		return
    26  	} else if string(toRead) != "Hello" {
    27  		t.Errorf("expecting %q, got %q", "Hello", string(toRead))
    28  		return
    29  	}
    30  	if n, err := reader.Read(toRead); n != 5 {
    31  		t.Errorf("expecting to read 5 bytes, read %d", n)
    32  		return
    33  	} else if err != nil {
    34  		t.Errorf("got error: %q", err.Error())
    35  		return
    36  	} else if string(toRead) != ", Wor" {
    37  		t.Errorf("expecting %q, got %q", ", Wor", string(toRead))
    38  		return
    39  	}
    40  	if n, err := reader.Read(toRead); n != 3 {
    41  		t.Errorf("expecting to read 3 bytes, read %d", n)
    42  		return
    43  	} else if err != nil {
    44  		t.Errorf("got error: %q", err.Error())
    45  		return
    46  	} else if string(toRead) != "ld!or" {
    47  		t.Errorf("expecting %q, got %q", "ld!or", string(toRead))
    48  		return
    49  	}
    50  	if n, err := reader.Read(toRead); n != 0 {
    51  		t.Errorf("expecting to read 0 bytes, read %d", n)
    52  		return
    53  	} else if err != io.EOF {
    54  		t.Errorf("expecting EOF")
    55  	}
    56  }
    57  
    58  func TestBufferWrite(t *testing.T) {
    59  	data := []byte("Beep  ")
    60  	writer := Buffer(data)[:0]
    61  	if n, err := writer.Write([]byte("J")); n != 1 {
    62  		t.Errorf("expecting to write 1 byte, wrote %d", n)
    63  		return
    64  	} else if err != nil {
    65  		t.Errorf("got error: %q", err.Error())
    66  		return
    67  	} else if string(data) != "Jeep  " {
    68  		t.Errorf("expecting %q, got %q", "Jeep  ", string(data))
    69  		return
    70  	}
    71  	if n, err := writer.Write([]byte("ohn")); n != 3 {
    72  		t.Errorf("expecting to write 3 bytes, wrote %d", n)
    73  		return
    74  	} else if err != nil {
    75  		t.Errorf("got error: %q", err.Error())
    76  		return
    77  	} else if string(data) != "John  " {
    78  		t.Errorf("expecting %q, got %q", "John  ", string(data))
    79  		return
    80  	}
    81  	if n, err := writer.Write([]byte("ny")); n != 2 {
    82  		t.Errorf("expecting to write 2 bytes, wrote %d", n)
    83  		return
    84  	} else if err != nil {
    85  		t.Errorf("got error: %q", err.Error())
    86  		return
    87  	} else if string(data) != "Johnny" {
    88  		t.Errorf("expecting %q, got %q", "Johnny", string(data))
    89  		return
    90  	}
    91  }
    92  
    93  func TestBufferReadFrom(t *testing.T) {
    94  	for n, test := range [...]struct {
    95  		byteReader
    96  		limit   int64
    97  		initial Buffer
    98  		result  []byte
    99  	}{
   100  		/*
   101  			{
   102  				3,
   103  				23,
   104  				make(Buffer, 10, 10),
   105  				[]byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 0, 1, 2, 0, 1, 2, 0, 1, 2, 0, 1, 2, 0, 1, 2, 0, 1, 2, 0, 1},
   106  			},
   107  			{
   108  				3,
   109  				31,
   110  				make(Buffer, 0, 0),
   111  				[]byte{0, 1, 2, 0, 1, 2, 0, 1, 2, 0, 1, 2, 0, 1, 2, 0, 1, 2, 0, 1, 2, 0, 1},
   112  			},
   113  		*/
   114  	} {
   115  		m, err := test.initial.ReadFrom(io.LimitReader(&test.byteReader, test.limit))
   116  		if err != nil {
   117  			t.Errorf("test %d: unexpected error: %s", n+1, err)
   118  		} else if m != test.limit {
   119  			t.Errorf("test %d: expecting to read %d bytes, read %d", n+1, test.limit, m)
   120  		} else if !bytes.Equal(test.result, test.initial) {
   121  			t.Errorf("test %d: expecting %v, got %v", n+1, test.result, test.initial)
   122  		}
   123  	}
   124  }
   125