---
title: "**echo**(1) acceptance tests"
author: The Subplot project
template: bash
bindings: echo.yaml
functions: echo.sh
bibliography: echo.bib
...
Introduction
=============================================================================
**echo**(1) is a Unix command line tool, which writes its command line
arguments to the standard output. This is a simple acceptance test
suite for the `/bin/echo` implementation.
For more information, see [@foo2020].
No arguments
=============================================================================
Run `/bin/echo` without arguments.
```scenario
when user runs echo without arguments
then exit code is 0
then standard output contains a newline
then standard error is empty
```
Hello, world
=============================================================================
This scenario runs `/bin/echo` to produce the output "hello, world".
```scenario
when user runs echo with arguments hello, world
then exit code is 0
then standard output contains "hello, world"
then standard error is empty
```
Test file
~~~~{.file #foo.dat}
This is a test file.
Two lines.
~~~~
# References