[new rule] VerticalWhitespace rule

[masters3d]

closes #548

@brentleyjones @Noobish1

[codecov-io]

Current coverage is 89.49% (diff: 89.90%)

Merging #747 into master will increase coverage by 0.01%

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[freak4pc]

I'm not a fan of the naming. Seems a bit too complex for something that is practically a 'single_newlines' or just a 'newlines' rule perhaps. Not sure if my name her is any good but vertical spacing is pretty confusing imho.

[proth]

Same here. I had to read to code to get an idea what this rule is for.

[masters3d]

@freak4pc Yeah, I am not in love with the name either but I didn't want to conflict with TrailingNewlineRule so I didn't want newLine in the name.

I really didn't find a consensus between these
*blank lines
*empty lines
*new lines
*blank space

so I picked vertical whitespace, another option could be vertical blank space

What about :
single_blank_line ?

[freak4pc]

'newline_spacing' that perhaps could expect min and max but default to 1,1?

Or 'single_newlines' also seems fitting imo.

Thoughts on naming @jpsim ?

[masters3d]

I am going to rename it to single_newline . Naming is hard.

[jpsim]

Thanks for your work on this @masters3d and your feedback @freak4pc!

I have two small suggestions: I think this should be named VerticalWhitespaceRule/vertical_whitespace and be configurable with a maxEmptyLines parameter that defaults to 1.

I don't think SingleNewLine is appropriate because for one empty line, there are two newline characters:

a

b

is actually a\n\nb.

[masters3d]

I changed back the name. I'd like to add maxEmptyLines configuration as another PR after this one lands.

[jpsim]

comma should go on previous line

[jpsim]

@masters3d I have some comments.

I'd like to add maxEmptyLines configuration as another PR after this one lands.

Fine by me.

[jpsim]

Thanks for driving this forward @masters3d!