---
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 `echo` implementation.

For more information, see [@foo2020].

No arguments
=============================================================================

Run `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 `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