moby/pkg/ioutils/buffer_test.go
Sebastiaan van Stijn 392ece2239
Improve coverage of pkg/ioutils/buffer
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
2017-02-28 14:11:15 +01:00

153 lines
3 KiB
Go

package 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))
}
}