:CoverageShowDiff is not implemented?!

[blueyed]

It looks like diff_path is not being added to the data anywhere!? (

vim-coverage/autoload/coverage.vim

Line 130 in 88d0204

if has_key(l:data, 'diff_path')

)

And (although mentioned in

vim-coverage/autoload/coverage.vim

Lines 184 to 185 in 88d0204

	" function(coverage_data) prototype. Coverage data format is as described in
	" the general help for this plugin.

) the coverage data format is not described in the help, is it?

[blueyed]

Ping @stgpetrovic (who committed this initially for "Goran Petrovic").

As it currently stands I would just remove it.

[dbarnett]

Aha, I found we actually have private shared coverage provider that patches this 'diff_path' key into the coverage data. I agree it shouldn't be there and we can be somewhat aggressive ripping it out on that end too, but could we get a sketch of how we'd want caching/reloading to work for #27 before proceeding here?

[blueyed]

Sure. The general idea would be to not use caching at all at first.

Can you share how it is used internally (in an abstract way)?

[dbarnett]

Sure, had to look up what it was doing… It says "diff_path" but it's actually not a diff but a snapshot of the file as it was at the time coverage was evaluated, used for diffing with the current version. The common case for this tool is to render server-side coverage data on submitted files, and it can actually be kind of awkward getting fresh coverage results from modified versions of the file. I filed #34 to discuss how to handle this kind of snapshotted coverage data functionality long term, since there's some complexity to getting it right.

[dbarnett]

Overall it makes sense coverage providers should be able to capture the snapshotted file contents. We could just rename it to something like file_snapshot and add it to the docs for the coverage provider interface. It should probably also support storing file contents as a list of strings and not just a file path since there won't always be a file snapshot on disk.