Add missing CLI and INI options for a consistent API

[astrofrog]

It would be nice to be able to customize the default tolerance and style to use globally as both have defaults set by 'historical reasons' that aren't necessarily sensible.

For style, one of the issues is that actually style could be more than just a string - e.g. a dict and so on. Is there a way to set global options such as these in e.g. conftest.py? (if so I can document that too).

Remaining TODOs (if we go ahead with this):

• Add some documentation about the options
• Add tests

[Cadair]

Is there a way to set global options such as these in e.g. conftest.py?

You can set these options in the pytest config (normally setup.cfg) but I don't know how that interacts with richer python objects? maybe we would need to parse a string in to a python object?

[ConorMacBride]

Is there a way to set global options such as these in e.g. conftest.py?

You can set these options in the pytest config (normally setup.cfg) but I don't know how that interacts with richer python objects? maybe we would need to parse a string in to a python object?

The pytest global options (probably) only supports returning one of these types. So I think it would be best to just recommend adding custom rc params to a new style file within the test directory, whose path (or URL) can just be referred to in the global pytest option as a string.

[ConorMacBride]

These changes should get the tests passing. I think we should do a new major version soon with the default style changed from "classic" to "default", as I think any changes to the Matplotlib default style are outside the scope of this package and should be made apparent by default when testing on different Matplotlib version.

[ConorMacBride]

Hi @astrofrog, there are some other options (noted in #198) which could be added to make the config more consistent. Do you agree we should add these options?

• Add mpl-baseline-path ini option (relative to where pytest was run).
• Add --mpl-use-full-test-name CLI option.
• Add mpl-hash-library ini option (relative to where pytest was run).
• Add --mpl-default-tolerance CLI and mpl-default-tolerance ini options.
• Add --mpl-default-style CLI and mpl-default-style ini options.
• Add --mpl-default-backend CLI and mpl-default-backend ini options.
• Add mpl-generate-summary ini option.

If so, would you like me to open a separate PR, or shall I just add them to this PR?

[astrofrog]

Sounds good - feel free to just add them to this PR if you like!

[astrofrog]

Thanks for all the work on this!