proposal: cmd/cover: add HTML summary page for files and respective coverage percentages

[Apoorvgarg-creator]

Proposal Details

I propose to improve the HTML test coverage reports by:

• a new summary page listing all files with their corresponding coverage percentages
• adding line numbers in the file view for easier debugging and a better user experience
• Adding total test coverage for the project
• If Backward compatibility is required, make the summary page and line numbers optional and configurable through CLI arguments.

Updates:

• We can also add support for line number toggle in the HTML.

Pull Request Change - https://go-review.googlesource.com/c/go/+/709375
This change currently doesn't handle backward compatibility as of now, but this is upto discussion.

[gopherbot]

Change https://go.dev/cl/709375 mentions this issue: cmd/cover: add HTML summary page for files and respective coverage percentages

[gabyhelp]

Related Issues

• cmd/cover: add number of uncovered lines #31519
• proposal: cmd/cover: add flags to print coverage percentages over packages or files #45846
• cmd/test: make it easy to -cover and browse #16768 (closed)
• proposal: cmd/covdata: html subcommand #71299 (closed)
• cmd/cover: improve html coverage report #25368 (closed)
• cmd/go: add test -coverhtml #22964
• proposal: cmd/cover: support branch coverage #70306
• cmd/cover: add total (statements) coverage to HTML output #16888 (closed)

Related Code Changes

• cmd/cover: add HTML summary page for files and respective coverage percentages
• cmd/cover: show covered and total line counts

_{(Emoji vote if this was helpful or unhelpful; more detailed feedback welcome in this discussion.)}

[seankhliao]

I personally think this is scope creep for cmd/cover.
Reporting as a whole like a summary page and "total" coverage should be left to other tools.