pytest-asptest 0.1.0

test Answer Set Programming programs

# ASP test
[pytest](https://docs.pytest.org) plugin to test ASP source code.

The principle is simple: you write inputs and outputs in a dedicated file, you run pytest,
pytest tells you which outputs are missing or unexpected.


## Installation

pip install pytest-asptest

Obviously, in order to run ASP, a solver must be installed. The only one handled for now is [clingo](https://github.com/potassco/clingo/releases)
from [potassco labs](https://potassco.org).


## simple example
Let's consider `dumbasp.lp`, an ASP code we want to be tested:

```asp
p(1..3).
q(X): p(X).
```

We want to test the rule in second line. We therefore put it into a block (consecutive lines without blank lines)
and give it a tag, `rule-q`:

```asp
p(1..3).

% TEST: rule-q
q(X): p(X).
```

Now we fill `test-rule-q.lp` with multiple tests:

```asp
% INPUT
% empty test: no input, no output
% INSATISFIABLE

% INPUT
p(1).
% OUTPUT
q(1).
% OUTPUT
q(2). % This will lead to an error : there is no such answer set.
```

Now, we can run again asptest:

pytest dumbasp.lp

It will report the testing process, indicating which tests are passed, and which are not.

More examples are available in the [Makefile](Makefile), or in [examples/](examples/)




## features
- multiple files support ; tags are shared
- handle generation of multiple answer sets, and strict keyword

### strict output
By default, the atoms given in output parts must be a *subset* of the atoms present in the answer set.
However, if you want to explicitely give *all* atoms that must appear in a given answer set,
you can write `% STRICT OUTPUT` instead of `% OUTPUT` in the test file.

### file uid
The file uid is given by default to all blocks of a file, and is the basename of the file.
You can therefore implement `test-queens.lp` to test all the blocks found in file `queens.lp`,
without having to manually tag all your blocks with it.

### CLI options
asptest add one option to pytest: `--uid-tests-dir`, allowing user to give to asptest the directory in which the `test-*.lp` files are.
For instance, `pytest . -vv --uid-tests-dir asp-test` would allow you to test all ASP files in the current directory, using the test files in `asp-test/` dir.

## TODO
- auto include input code into output with flag *with-output* on OUTPUT lines in test files