Containerise robota-core

[tcassar]

Running tests causes three skips if graphviz is not installed. To circumvent these problems, containerising the application with Docker would be useful and so I shall do it.

[suzanneEmbury]

Sounds good, @tcassar . I guess most of the tests don't need graphviz, though?

Can you point me at the tests that need it?

[SauravMaheshkar]

Another viable option might be to create a decorator which checks if a particular package is installed. There are some versions of this available online, my personal favourite is source :

def has_package(package: str) -> bool:
    r"""Returns :obj:`True` in case :obj:`package` is installed."""
    if '|' in package:
        return any(has_package(p) for p in package.split('|'))

    req = Requirement(package)
    if find_spec(req.name) is None:
        return False
    module = import_module(req.name)
    if not hasattr(module, '__version__'):
        return True

    version = module.__version__
    # `req.specifier` does not support `.dev` suffixes, e.g., for
    # `pyg_lib==0.1.0.dev*`, so we manually drop them:
    if '.dev' in version:
        version = '.'.join(version.split('.dev')[:-1])

    return version in req.specifier

def withPackage(*args: str) -> Callable:
    r"""A decorator to skip tests if certain packages are not installed.
    Also supports version specification.
    """
    na_packages = set(package for package in args if not has_package(package))

    if len(na_packages) == 1:
        reason = f"Package {list(na_packages)[0]} not found"
    else:
        reason = f"Packages {na_packages} not found"

    def decorator(func: Callable) -> Callable:
        import pytest
        return pytest.mark.skipif(len(na_packages) > 0, reason=reason)(func)

    return decorator

[suzanneEmbury]

Thanks @SauravMaheshkar - this is an interesting approach that we can keep in mind for the future, once we have dealt with some of the bigger problems.

In checking over the PR ( #13 ) I realised we had some of our commit visualisation code packaged along with robota-core, and that was why graphviz was needed. We should look at whether this is the best place for this code at some point, but in terms of this issue, I now at least understand why it needs to be installed.