How can I write a Go test that writes to stdin?

Question

Say that I have a simple application that reads lines from stdin and simply echoes it back to stdout. For example:

package main

import (
    \"bufio\"
    \         


        

Answer 1

Here is an example that writes to stdin and reads from stdout. Note that it does not work because the output contains "> " at first. Still, you can modify it to suit your needs.

func TestInput(t *testing.T) {
    subproc := exec.Command("yourCmd")
    input := "abc\n"
    subproc.Stdin = strings.NewReader(input)
    output, _ := subproc.Output()

    if input != string(output) {
        t.Errorf("Wanted: %v, Got: %v", input, string(output))
    }
    subproc.Wait()
}