par - Modules can leave it a mess

[AugustT]

Some modules, like PrintMap, change the values of par() without resetting them at the end. This is naughty and could be caught in module tests (check original par values against values returned after the module is run). We could also force them to be returned to defaults by capturing the values at the beginning of the workflow and resetting them at the end.

[timcdlucas]

Yes think getting workflow to do that is sensible.

As always, low bar to module contribution is useful. Even though getting modules to catch and reset par isn't that hard, it's more that we don't want the documentation for what modules must do to be long.

Having to read the whole CRAN guidelines just in case there's something you hadn't thought of that's not allowed is a pain for example. We want to avoid that.