# doctest
An OTP library to test `-doc` attributes.
## Requirements
OTP >= 27.
## Installation
```erlang
% rebar.config
{profiles, [
{test, [
{deps, [{doctest, "0.2.0"}]}
]}
]}.
```
## Usage
### Via parse_transform
Take this module:
````erlang
-module(math).
-export([add/2]).
-ifdef(TEST).
-include_lib("doctest/include/doctest.hrl").
% -doctest <see the options section>.
-endif.
-doc """
Adds two numbers together.
_Example_:
```erlang
1> math:add(0, 1).
1
2> math:add(
.. 1,
.. 1
.. ).
2
```
""".
add(A, B) ->
A+B.
````
> Note that the code is defined like the Erlang shell, starting with `N> `, where `N` is a number, and continues in multiple lines with `.. `. The result is a value without starting with those shell symbols.
Now, by running `rebar3 eunit`:
```shell
Finished in 0.018 seconds
2 tests, 0 failures
```
By changing the first test to:
```erlang
1> math:add(1, 1).
1
```
And running `rebar3 eunit` again:
```shell
Failures:
1) doctest_parse_transform:-parse/4-fun-0-/0:26
Failure/Error: ?assertEqual(1, math:add(1, 1))
expected: 1
got: 2
%% eunit_proc.erl:583:in `eunit_proc:run_group/2`
Output:
Output:
Finished in 0.010 seconds
2 tests, 1 failures
```
### Options
Options are defined via the `-doctest` attribute and can be defined multiple times.
#### Available options
- `boolean()`: enable or disable tests.
```erlang
-doctest true.
```
- `[{atom(), arity()}]` | `all`: define the functions to be tested.
```erlang
-doctest [add/2].
```
- `map()`: define all or partial options.
```erlang
-doctest #{
enabled => true,
funs => [add/2]
}.
```
### Important
Currently, only exported functions can be tested.
## TODO
- [ ] More tests;
- [ ] Ability to test modules via function and not only via `parse_transform`;
- [ ] Maybe add a mechanism to test non-exported functions, but probably this makes no sense;
- [ ] Improve docs;
- [ ] Implement `-moduledoc` tests in the same way that for `-doc`.
## Sponsors
If you like this tool, please consider [sponsoring me](https://github.com/sponsors/williamthome).
I'm thankful for your never-ending support :heart:
I also accept coffees :coffee:
[!["Buy Me A Coffee"](https://www.buymeacoffee.com/assets/img/custom_images/orange_img.png)](https://www.buymeacoffee.com/williamthome)
## Contributing
### Issues
Feel free to [submit an issue on Github](https://github.com/williamthome/doctest/issues/new).
## License
Copyright (c) 2024 [William Fank Thomé](https://github.com/williamthome)
`doctest` is 100% open source and community-driven. All components are available under the Apache 2 License on [GitHub](https://github.com/williamthome/doctest).
See [LICENSE.md](LICENSE.md) for more information.