memio - readwrite_test.go

     1  package memio
     2  
     3  import (
     4  	"io"
     5  	"testing"
     6  )
     7  
     8  var (
     9  	_ io.Reader     = new(ReadMem)
    10  	_ io.Closer     = new(ReadMem)
    11  	_ io.Seeker     = new(ReadMem)
    12  	_ io.WriterTo   = new(ReadMem)
    13  	_ io.ByteReader = new(ReadMem)
    14  	_ io.ReaderAt   = new(ReadMem)
    15  
    16  	_ io.Writer     = new(WriteMem)
    17  	_ io.Closer     = new(WriteMem)
    18  	_ io.Seeker     = new(WriteMem)
    19  	_ io.ReaderFrom = new(WriteMem)
    20  	_ io.ByteWriter = new(WriteMem)
    21  	_ io.WriterAt   = new(WriteMem)
    22  )
    23  
    24  func TestReadWriteRead(t *testing.T) {
    25  	data := []byte("Hello, World!")
    26  	reader := OpenMem(&data)
    27  	toRead := make([]byte, 5)
    28  	if n, err := reader.Read(toRead); n != 5 {
    29  		t.Errorf("expecting to read 5 bytes, read %d", n)
    30  		return
    31  	} else if err != nil {
    32  		t.Errorf("got error: %q", err.Error())
    33  		return
    34  	} else if string(toRead) != "Hello" {
    35  		t.Errorf("expecting %q, got %q", "Hello", string(toRead))
    36  		return
    37  	}
    38  	if n, err := reader.Read(toRead); n != 5 {
    39  		t.Errorf("expecting to read 5 bytes, read %d", n)
    40  		return
    41  	} else if err != nil {
    42  		t.Errorf("got error: %q", err.Error())
    43  		return
    44  	} else if string(toRead) != ", Wor" {
    45  		t.Errorf("expecting %q, got %q", ", Wor", string(toRead))
    46  		return
    47  	}
    48  	if n, err := reader.Read(toRead); n != 3 {
    49  		t.Errorf("expecting to read 3 bytes, read %d", n)
    50  		return
    51  	} else if err != nil {
    52  		t.Errorf("got error: %q", err.Error())
    53  		return
    54  	} else if string(toRead) != "ld!or" {
    55  		t.Errorf("expecting %q, got %q", "ld!or", string(toRead))
    56  		return
    57  	}
    58  	if n, err := reader.Read(toRead); n != 0 {
    59  		t.Errorf("expecting to read 0 bytes, read %d", n)
    60  		return
    61  	} else if err != io.EOF {
    62  		t.Errorf("expecting EOF")
    63  	}
    64  	if pos, err := reader.Seek(2, 0); pos != 2 {
    65  		t.Errorf("expected to be at position 2, got %d", pos)
    66  		return
    67  	} else if err != nil {
    68  		t.Errorf("got error: %q", err.Error())
    69  		return
    70  	} else if n, err := reader.Read(toRead); n != 5 {
    71  		t.Errorf("expecting to read 5 bytes, read %d", n)
    72  		return
    73  	} else if err != nil {
    74  		t.Errorf("got error: %q", err.Error())
    75  		return
    76  	} else if string(toRead) != "llo, " {
    77  		t.Errorf("expecting %q, got %q", "llo, ", string(toRead))
    78  		return
    79  	}
    80  	if pos, err := reader.Seek(2, 1); pos != 9 {
    81  		t.Errorf("expected to be at position 9, got %d", pos)
    82  		return
    83  	} else if err != nil {
    84  		t.Errorf("got error: %q", err.Error())
    85  		return
    86  	} else if n, err := reader.Read(toRead); n != 4 {
    87  		t.Errorf("expecting to read 4 bytes, read %d", n)
    88  		return
    89  	} else if err != nil {
    90  		t.Errorf("got error: %q", err.Error())
    91  		return
    92  	} else if string(toRead) != "rld! " {
    93  		t.Errorf("expecting %q, got %q", "rld! ", string(toRead))
    94  		return
    95  	}
    96  	if pos, err := reader.Seek(-6, 2); pos != 7 {
    97  		t.Errorf("expected to be at position 7, got %d", pos)
    98  		return
    99  	} else if err != nil {
   100  		t.Errorf("got error: %q", err.Error())
   101  		return
   102  	} else if n, err := reader.Read(toRead); n != 5 {
   103  		t.Errorf("expecting to read 5 bytes, read %d", n)
   104  		return
   105  	} else if err != nil {
   106  		t.Errorf("got error: %q", err.Error())
   107  		return
   108  	} else if string(toRead) != "World" {
   109  		t.Errorf("expecting %q, got %q", "World", string(toRead))
   110  		return
   111  	}
   112  	if _, err := reader.Seek(1, 0); err != nil {
   113  		t.Errorf("got error: %q", err.Error())
   114  		return
   115  	}
   116  	reader.Close()
   117  }
   118  
   119  func TestReadWriteWrite(t *testing.T) {
   120  	data := []byte("Beep")
   121  	writer := OpenMem(&data)
   122  	if n, err := writer.Write([]byte("J")); n != 1 {
   123  		t.Errorf("expecting to write 1 byte, wrote %d", n)
   124  		return
   125  	} else if err != nil {
   126  		t.Errorf("got error: %q", err.Error())
   127  		return
   128  	} else if string(data) != "Jeep" {
   129  		t.Errorf("expecting %q, got %q", "Jeep", string(data))
   130  		return
   131  	}
   132  	if n, err := writer.Write([]byte("ohn")); n != 3 {
   133  		t.Errorf("expecting to write 3 bytes, wrote %d", n)
   134  		return
   135  	} else if err != nil {
   136  		t.Errorf("got error: %q", err.Error())
   137  		return
   138  	} else if string(data) != "John" {
   139  		t.Errorf("expecting %q, got %q", "John", string(data))
   140  		return
   141  	}
   142  	if n, err := writer.Write([]byte("ny")); n != 2 {
   143  		t.Errorf("expecting to write 2 bytes, wrote %d", n)
   144  		return
   145  	} else if err != nil {
   146  		t.Errorf("got error: %q", err.Error())
   147  		return
   148  	} else if string(data) != "Johnny" {
   149  		t.Errorf("expecting %q, got %q", "Johnny", string(data))
   150  		return
   151  	}
   152  	if pos, err := writer.Seek(0, 0); pos != 0 {
   153  		t.Errorf("expected to be at position 0, got %d", pos)
   154  	} else if err != nil {
   155  		t.Errorf("got error: %q", err.Error())
   156  		return
   157  	} else if n, err := writer.Write([]byte("Edmund")); n != 6 {
   158  		t.Errorf("expecting to write 6 bytes, wrote %d", n)
   159  		return
   160  	} else if err != nil {
   161  		t.Errorf("got error: %q", err.Error())
   162  		return
   163  	} else if string(data) != "Edmund" {
   164  		t.Errorf("expecting %q, got %q", "Edmund", string(data))
   165  		return
   166  	}
   167  	if pos, err := writer.Seek(-4, 2); pos != 2 {
   168  		t.Errorf("expected to be at position 0, got %d", pos)
   169  	} else if err != nil {
   170  		t.Errorf("got error: %q", err.Error())
   171  		return
   172  	} else if n, err := writer.Write([]byte("war")); n != 3 {
   173  		t.Errorf("expecting to write 3 bytes, wrote %d", n)
   174  		return
   175  	} else if err != nil {
   176  		t.Errorf("got error: %q", err.Error())
   177  		return
   178  	} else if string(data) != "Edward" {
   179  		t.Errorf("expecting %q, got %q", "Edward", string(data))
   180  		return
   181  	}
   182  	if pos, err := writer.Seek(1, 1); pos != 6 {
   183  		t.Errorf("expected to be at position 6, got %d", pos)
   184  	} else if err != nil {
   185  		t.Errorf("got error: %q", err.Error())
   186  		return
   187  	} else if n, err := writer.Write([]byte("o")); n != 1 {
   188  		t.Errorf("expecting to write 1 bytes, wrote %d", n)
   189  		return
   190  	} else if err != nil {
   191  		t.Errorf("got error: %q", err.Error())
   192  		return
   193  	} else if string(data) != "Edwardo" {
   194  		t.Errorf("expecting %q, got %q", "Edwardo", string(data))
   195  		return
   196  	}
   197  	writer.Close()
   198  	_, err := writer.Seek(0, 0)
   199  	if err != ErrClosed {
   200  		t.Errorf("expecting close error")
   201  		return
   202  	}
   203  	_, err = writer.Write([]byte("Beep"))
   204  	if err != ErrClosed {
   205  		t.Errorf("expecting close error")
   206  		return
   207  	}
   208  }