[Feature] Dialyzer plugin option to save raw output to the dialyzer warnings file

[srijan]

Dialyzer supports the --raw flag to:

... output the raw analysis results (Erlang terms) instead of the formatted result. The raw format is easier to post-process (for example, to filter warnings or to output HTML pages).

This will let us process the result file using Erlang code to output an HTML page.

Suggested option name: output_format, with possible values: formatted and raw, with default as formatted.

If people are okay with this, I can raise a PR with a cleaned up version of greyorange@9e65394

[ferd]

yeah that sounds like something that would require an absolute minimal amount of code and should be no problem to support by just dropping the format_warnings internal call to just go for the default format. One thing you'll probably find annoying is that the file paths require custom formatting to be in the format you expect, and that is done based on the Opts term we have internally since we use paths in _build/ when analyzing.

[srijan]

I found that the Source reported in the raw data has the actual source path, not _build/* (except for deps).

But, I still wanted paths relative to project root, and also wanted to extract app names (for multi-app projects). So, went with a custom rebar plugin approach to generate the HTML.

Another benefit of running as a plugin: I can use the rebar_dialyzer_format:format_warnings/2 function. I used a frontend JS library to convert the ansi color codes to HTML span definitions.

Report looks like this:

Will raise the PR for raw output format.

[paulo-ferraz-oliveira]

Oh, that's nice.

@srijan, if you share details on what JS lib. you used I/we could work on a plugin for this - what say you?
(sorry for hijacking the issue - feel free to hit me up on the Erlanger Slack)

[srijan]

@paulo-ferraz-oliveira - this is the plugin: https://github.com/srijan/rebar3_dialyzer_html (still work in progress, so ignore the bad code).

I'm using ansi_up to convert the warning text after page load.

One potential improvement is to actually do the conversion in Erlang side to remove the dependency on JS.

[paulo-ferraz-oliveira]

Ah, it's already a plugin. Good 😄 Don't forget to announce when 0.1.0 (or whatever you choose comes out) on Slack. Will take a look. Great stuff, thanks.