README
¶
fakeio pacakge for Go
fakeio is a small library to fake stdout/stderr/stdin.
This is mainly for unit testing of CLI applications. Please see documentation
for more details.
Installation
$ go get github.com/rhysd/go-fakeio
Usage
Basic usage:
import (
"bufio"
"github.com/rhysd/go-fakeio"
)
// Fake stdout and input 'hello' to stdin
fake := fakeio.Stdout().Stdin("hello!")
defer fake.Restore()
// Do something...
// "hello!" is stored to variable `i`
i, err := bufio.NewReader(os.Stdin).ReadString('!')
// At this point, this line outputs nothing
fmt.Print("bye")
// "bye" is stored to variable `o`
o, err := fake.String()
Faking stdout/stderr/stdin
Faking stderr:
fake := fakeio.Stderr()
defer fake.Restore()
Faking stdin:
fake, err := fakeio.Stdin("hello")
defer fake.Restore()
Faking stderr/stdout/stdin
fake := fakeio.Stderr().Stdout().Stdin("Faked input to stdin")
defer fake.Restore()
Read bufferred stdout/stderr
Reading as string:
s, err := fake.String()
if err != nil {
// Faking IO failed
panic(err)
}
fmt.Println(s)
Reading as bytes:
b, err := fake.Bytes()
if err != nil {
// Faking IO failed
panic(err)
}
fmt.Println(b)
Reading via io.Reader interface:
s := bufio.NewScanner(fake)
for s.Scan() {
// Reading line by line
line := s.Text()
fmt.Println(line)
}
if s.Err() != nil {
// Error happened while reading
panic(s.Err)
}
Shortcut
.Do() is a shortcut
s, err := fakeio.Stderr().Stdout().Do(func () {
// Do something
// Faked stderr and stdout are restored at exit of this scope
})
if err != nil {
// Faking IO failed
panic(err)
}
fmt.Println(s)
Examples
Please see examples for actual examples.
Repository
https://github.com/rhysd/go-fakeio
License
Documentation
¶
Overview ¶
Package fakeio is a small library to fake stdout/stderr/stdin mainly for unit testing.
Following example fakes stdout/stderr/stdin. Set 'from stdin!' as stdin and get output from both stdout and stderr as string.
f := fakeio.Stdout().Stderr().Stdin("from stdin!")
fromInput, err := bufio.NewReader(os.Stdin).ReadString('!')
if err != nil {
f.Restore()
panic(err)
}
fmt.Println("from stdout!")
fmt.Fprintln(os.Stderr, "from stderr!")
fromOutput, err := f.String()
if err != nil {
f.Restore()
panic(err)
}
// 'defer' is better, but here it's unavailable due to output test
f.Restore()
// Output: from stdin!
fmt.Println(fromInput)
// Output:
// from stdout!
// from stderr!
fmt.Println(fromOutput)
Please read example/example_test.go to see live examples.
If you find some bugs, please report it to repository page: https://github.com/rhysd/go-fakeio
Index ¶
- type FakedIO
- func (fake *FakedIO) Bytes() ([]byte, error)
- func (fake *FakedIO) CloseStdin() *FakedIO
- func (fake *FakedIO) Do(f func()) (string, error)
- func (fake *FakedIO) Err() error
- func (fake *FakedIO) Read(p []byte) (int, error)
- func (fake *FakedIO) Restore()
- func (fake *FakedIO) Stderr() *FakedIO
- func (fake *FakedIO) Stdin(in string) *FakedIO
- func (fake *FakedIO) StdinBytes(in []byte) *FakedIO
- func (fake *FakedIO) Stdout() *FakedIO
- func (fake *FakedIO) String() (string, error)
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type FakedIO ¶
type FakedIO struct {
// contains filtered or unexported fields
}
FakedIO represents state of faking stdout/stderr/stdin. Restore() must be called finally to restore the state.
func Stderr ¶
func Stderr() *FakedIO
Stderr starts to fake stderr and returns fakedIO object to restore input/output finally
func Stdin ¶
Stdin sets given string as faked stdin input and returns fakedIO object to restore input/output finally
func StdinBytes ¶
StdinBytes sets given bytes as faked stdin input and returns fakedIO object to restore input/output finally
func Stdout ¶
func Stdout() *FakedIO
Stdout starts to fake stdout and returns fakedIO object to restore input/output finally
func (*FakedIO) CloseStdin ¶
CloseStdin closes faked stdin
func (*FakedIO) Restore ¶
func (fake *FakedIO) Restore()
Restore restores faked stdin/stdout/stderr. This must be called finally.
func (*FakedIO) StdinBytes ¶
StdinBytes sets input buffer for stdin with bytes
Source Files