mirror of https://github.com/docker/cli.git
31 lines
961 B
Go
31 lines
961 B
Go
|
package test
|
||
|
|
|
||
|
|
import (
|
||
|
|
"io"
|
||
|
|
)
|
||
|
|
|
||
|
|
// WriterWithHook is an io.Writer that calls a hook function
|
||
|
|
// after every write.
|
||
|
|
// This is useful in testing to wait for a write to complete,
|
||
|
|
// or to check what was written.
|
||
|
|
// To create a WriterWithHook use the NewWriterWithHook function.
|
||
|
|
type WriterWithHook struct {
|
||
|
|
actualWriter io.Writer
|
||
|
|
hook func([]byte)
|
||
|
|
}
|
||
|
|
|
||
|
|
// Write writes p to the actual writer and then calls the hook function.
|
||
|
|
func (w *WriterWithHook) Write(p []byte) (n int, err error) {
|
||
|
|
defer w.hook(p)
|
||
|
|
return w.actualWriter.Write(p)
|
||
|
|
}
|
||
|
|
|
||
|
|
var _ io.Writer = (*WriterWithHook)(nil)
|
||
|
|
|
||
|
|
// NewWriterWithHook returns a new WriterWithHook that still writes to the actualWriter
|
||
|
|
// but also calls the hook function after every write.
|
||
|
|
// The hook function is useful for testing, or waiting for a write to complete.
|
||
|
|
func NewWriterWithHook(actualWriter io.Writer, hook func([]byte)) *WriterWithHook {
|
||
|
|
return &WriterWithHook{actualWriter: actualWriter, hook: hook}
|
||
|
|
}
|