Add printers to the command line runner

[arturdryomov]

A bit of context to understand the motivation behind the change.

Me and @artem-zinnatullin are working on the Bazel rule for Detekt. One of the features of the rule is the persistent workers support.

• The thing with workers is that standard inputs and outputs are reserved for the Bazel / worker communication. Since there is no API to limit Detekt standard output usage we were forced to create a workaround which replaces system standard output streams with file-based ones.
• This worked fine (though a bit hacky) until we thought about multiplexing. The multiplexing will change the flow, essentially we’ll be calling multiple Detekt runners in parallel. Unfortunately, the replace-system-streams workaround will not work in a multi-thread environment since it will be almost impossible to understand which runner printed which output to a singleton system stream.

If this change is accepted (and eventually published) we’ll be able to make Detekt invocations more or less hermetic. At the same time, the API change is backwards-compatible (arguments fall back to default values) and kinda makes sense abstracting from our personal needs (there is no way to change printers since ProcessingSettings in Runner are not accessible).

[codecov-io]

Codecov Report

Merging #2188 into master will increase coverage by 0.36%.
The diff coverage is 100%.

@@             Coverage Diff              @@
##             master    #2188      +/-   ##
============================================
+ Coverage     80.75%   81.12%   +0.36%     
- Complexity     2032     2055      +23     
============================================
  Files           338      339       +1     
  Lines          5841     5874      +33     
  Branches       1066     1070       +4     
============================================
+ Hits           4717     4765      +48     
+ Misses          554      536      -18     
- Partials        570      573       +3

Impacted Files	Coverage Δ	Complexity Δ
...ain/kotlin/io/gitlab/arturbosch/detekt/cli/Main.kt	50% <100%> (+50%)	7 <1> (+7)	⬆️
.../io/gitlab/arturbosch/detekt/cli/runners/Runner.kt	88.88% <100%> (+1.08%)	10 <2> (+1)	⬆️
...b/arturbosch/detekt/rules/style/ForbiddenImport.kt	95% <0%> (-0.66%)	9% <0%> (ø)
...bosch/detekt/rules/providers/StyleGuideProvider.kt	100% <0%> (ø)	3% <0%> (ø)	⬇️
...sch/detekt/rules/style/ForbiddenPublicDataClass.kt	90.47% <0%> (ø)	13% <0%> (?)
...gitlab/arturbosch/detekt/cli/runners/AstPrinter.kt	77.14% <0%> (+2.85%)	1% <0%> (+1%)	⬆️
...in/io/gitlab/arturbosch/detekt/api/SplitPattern.kt	85.18% <0%> (+6.23%)	17% <0%> (ø)	⬇️
.../kotlin/io/gitlab/arturbosch/detekt/cli/CliArgs.kt	100% <0%> (+7.4%)	6% <0%> (ø)	⬇️
...ab/arturbosch/detekt/cli/runners/ConfigExporter.kt	20% <0%> (+20%)	1% <0%> (+1%)	⬆️

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[schalkms]

Fine for me, since this PR is backwards compatible.

[schalkms]

@arturdryomov the bazel detekt plugin is cool. Thanks for doing this! +1 star

[arturdryomov]

@schalkms, sure — expanded the test suite a bit.

[schalkms]

Thanks! 🥇