Support diktat - Kotlin code style analyzer

[Cheshiriks]

Diktat is a strict coding standard for Kotlin and a custom set of rules for detecting code smells, code style issues and bugs.

https://github.com/cqfn/diKTat/blob/master/README.md

• add DiktatStep
• add tests for diktat

[nedtwigg]

Thanks, great PR! Few minor changes required before merging.

[nedtwigg]

• Oh! Also all three CHANGES.md

[Cheshiriks]

Thanks, great PR! Few minor changes required before merging.

Thanks! Added changes to the CHANGES.md files and made the necessary edits.

[akuleshov7]

I guess it should be linked with #409

[nedtwigg]

Thanks very much, great PR! One minor question left. Don't worry about changing it, just answer the question and I can change it (I've got a few other tiny nits which are easier if I just do them).

Btw, I find it easier to review PRs if you push up new commits, rather than force-pushing over old-ones. We can always squash down if things get messy, but we can't unsquash :)

[nedtwigg]

Thanks for a great PR @Cheshiriks! Published in plugin-gradle 5.10.0 and plugin-maven 2.8.0.

[nedtwigg]

• Btw, we should definitely add links to the diKTat docs for gradle and maven.

[petertrr]

Hey @nedtwigg, we have added description of spotless integration in diktat readme in saveourtool/diktat#762, you can check it out here 👍

[nedtwigg]

Great, thanks! It might be worth linking directly to the gradle and maven pages rather than the Spotless root docs, but it looks great as-is. Spotless is glad to have another formatter, hopefully the formatter is glad to have a Spotless :)

[lyharrietbui]

Hi @nedtwigg I am trying to integrate diktat with spotless. Does Spotless read the diktat config at configuration-time? It seems like I have to add the diktat-analysis.yml at configuration time during the build process for it to be available for

configure<SpotlessExtension> {
        kotlin {
           diktat("1.0.3").configFile(diktat-analysis.yml)
       }
}

[nedtwigg]

Does Spotless read the diktat config at configuration-time?

Yes, because it's needed for up-to-date checks. If you want to download a config from a remote URL, I recommend https://github.com/diffplug/blowdryer

[akuleshov7]

Does Spotless read the diktat config at configuration-time?

Yes, because it's needed for up-to-date checks. If you want to download a config from a remote URL, I recommend https://github.com/diffplug/blowdryer

@lyharrietbui I do not think that you need to download config file from the remote URL, you can put it to your project folder. Gradle will automatically calculate paths from the rootDir and you will override the default configuration with the custom one.