Add Tabular Diff for CSV files

[KN4CK3R]

Implements request #14320 The rendering of csv files does match the diff style.

A simple change:

Changes in different areas (note the jumping line numbers):

A removed column is rendered without marking all rows as changed:

Toggle view:

[KN4CK3R]

File sizes are now restricted to 512kb.

This is a problem for the old csv markup renderer because there is no way to return errors from the rendering process and fall back to the normal text rendering. If the file is too large the content is now rendered without styling:

With a fallback to the normal rendering combined with an error message from the markup renderer it could be displayed like on GitHub:

Additionaly the csv parser errors are now propagated to the ui:

[kdumontnu]

Awesome. Thanks for adding unit tests! 💯

[kdumontnu]

The problem is the empty line which is not handled as expected by the Go CSV reader (golang/go#39119). I don't think this PR could and should support all variations in CSV files out there. For usual field,field,field files it works as itended and that should be the majority of CSV files.

Agreed. I've added some support to the issue/PR you linked, but it appears that the go maintainers are not interested in extending the encode/csv library and suggest using other libraries. I might investigate other csv reader libraries.

[lunny]

@zeripath need your review.

concerns addressed

[6543]

looks ok, just found one dark-theme issue and one render issue:

on the Diff View the ® dont get displayed correctly, while on normal file-view it is ...
both views have an collor issue (white line), whitch should be hidden at all ...

[KN4CK3R]

on the Diff View the ® dont get displayed correctly, while on normal file-view it is ...

Could you please provide the sample file? Looks like an encoding issue. I have added a call to charset.ToUTF8WithFallback like in view.go. There is an unneeded call too (line 485 and 498):

gitea/routers/repo/view.go

Lines 485 to 498 in 2b9e0b4

	buf = charset.ToUTF8WithFallback(append(buf, d...))
	readmeExist := markup.IsReadmeFile(blob.Name())
	ctx.Data["ReadmeExist"] = readmeExist
	if markupType := markup.Type(blob.Name()); markupType != "" {
	ctx.Data["IsMarkup"] = true
	ctx.Data["MarkupType"] = markupType
	ctx.Data["FileContent"] = string(markup.Render(blob.Name(), buf, path.Dir(treeLink), ctx.Repo.Repository.ComposeDocumentMetas()))
	} else if readmeExist {
	ctx.Data["IsRenderedHTML"] = true
	ctx.Data["FileContent"] = strings.ReplaceAll(
	gotemplate.HTMLEscapeString(string(buf)), "\n", `<br>`,
	)
	} else {
	buf = charset.ToUTF8WithFallback(buf)

Edit: I found the file and it looks good with the change.

[lafriks]

Sorry accidentally requested review 😸