photoprism/internal/util/capture.go

package util

import (
	"bytes"
	"io"
	"os"
)

// Returns output to stdout and stderr for testing
func CaptureOutput(f func()) string {
	r, w, err := os.Pipe()
	if err != nil {
		panic(err)
	}

	stdout := os.Stdout
	os.Stdout = w
	defer func() {
		os.Stdout = stdout
	}()

	stderr := os.Stderr
	os.Stderr = w
	defer func() {
		os.Stderr = stderr
	}()

	f()
	w.Close()

	var buf bytes.Buffer
	io.Copy(&buf, r)

	return buf.String()
}