package ioutils // import "github.com/docker/docker/pkg/ioutils" import ( "bytes" "testing" ) func TestFixedBufferCap(t *testing.T) { buf := &fixedBuffer{buf: make([]byte, 0, 5)} n := buf.Cap() if n != 5 { t.Fatalf("expected buffer capacity to be 5 bytes, got %d", n) } } func TestFixedBufferLen(t *testing.T) { buf := &fixedBuffer{buf: make([]byte, 0, 10)} buf.Write([]byte("hello")) l := buf.Len() if l != 5 { t.Fatalf("expected buffer length to be 5 bytes, got %d", l) } buf.Write([]byte("world")) l = buf.Len() if l != 10 { t.Fatalf("expected buffer length to be 10 bytes, got %d", l) } // read 5 bytes b := make([]byte, 5) buf.Read(b) l = buf.Len() if l != 5 { t.Fatalf("expected buffer length to be 5 bytes, got %d", l) } n, err := buf.Write([]byte("i-wont-fit")) if n != 0 { t.Fatalf("expected no bytes to be written to buffer, got %d", n) } if err != errBufferFull { t.Fatalf("expected errBufferFull, got %v", err) } l = buf.Len() if l != 5 { t.Fatalf("expected buffer length to still be 5 bytes, got %d", l) } buf.Reset() l = buf.Len() if l != 0 { t.Fatalf("expected buffer length to still be 0 bytes, got %d", l) } } func TestFixedBufferString(t *testing.T) { buf := &fixedBuffer{buf: make([]byte, 0, 10)} buf.Write([]byte("hello")) buf.Write([]byte("world")) out := buf.String() if out != "helloworld" { t.Fatalf("expected output to be \"helloworld\", got %q", out) } // read 5 bytes b := make([]byte, 5) buf.Read(b) // test that fixedBuffer.String() only returns the part that hasn't been read out = buf.String() if out != "world" { t.Fatalf("expected output to be \"world\", got %q", out) } } func TestFixedBufferWrite(t *testing.T) { buf := &fixedBuffer{buf: make([]byte, 0, 64)} n, err := buf.Write([]byte("hello")) if err != nil { t.Fatal(err) } if n != 5 { t.Fatalf("expected 5 bytes written, got %d", n) } if string(buf.buf[:5]) != "hello" { t.Fatalf("expected \"hello\", got %q", string(buf.buf[:5])) } n, err = buf.Write(bytes.Repeat([]byte{1}, 64)) if n != 59 { t.Fatalf("expected 59 bytes written before buffer is full, got %d", n) } if err != errBufferFull { t.Fatalf("expected errBufferFull, got %v - %v", err, buf.buf[:64]) } } func TestFixedBufferRead(t *testing.T) { buf := &fixedBuffer{buf: make([]byte, 0, 64)} if _, err := buf.Write([]byte("hello world")); err != nil { t.Fatal(err) } b := make([]byte, 5) n, err := buf.Read(b) if err != nil { t.Fatal(err) } if n != 5 { t.Fatalf("expected 5 bytes read, got %d - %s", n, buf.String()) } if string(b) != "hello" { t.Fatalf("expected \"hello\", got %q", string(b)) } n, err = buf.Read(b) if err != nil { t.Fatal(err) } if n != 5 { t.Fatalf("expected 5 bytes read, got %d", n) } if string(b) != " worl" { t.Fatalf("expected \" worl\", got %s", string(b)) } b = b[:1] n, err = buf.Read(b) if err != nil { t.Fatal(err) } if n != 1 { t.Fatalf("expected 1 byte read, got %d - %s", n, buf.String()) } if string(b) != "d" { t.Fatalf("expected \"d\", got %s", string(b)) } }