Incorrect linting for single-expression functions.

saveourtool / diktat

Strict coding standard for Kotlin and a custom set of rules for detecting code smells, code style issues and bugs

MIT License

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Describe the bug

Incorrect [WRONG_NEWLINES] and [WRONG_INDENTATION] lint warnings generated for single-expression functions

Here's an example of the this bug with the reported warnings:

Expected behavior

There should not be any warning.

Observed behavior

[WRONG_NEWLINES] and [WRONG_INDENTATION] lint warnings are generated.

Steps to Reproduce

Copy the following reproducible code:

fun absolute(x: Int) =
if (x > 0) x
else -x

Run the diktat linter with default configurations.

Environment information

diktat version: 0.1.2
build tool (maven/gradle): gradle
how is diktat run (CLI, plugin, etc.): gradle task
kotlin version: 1.4.10
operating system: Windows 10 Build 1909
link to a project (if your project is public): I haven't published the project to any public version control.

Hi @Animeshz , thanks for your feedback!

Regarding indentation errors - could you try to set extendedIndentAfterOperators and extendedIndentBeforeDot to false in indentation configuration, like this:

- name: WRONG_INDENTATION
  enabled: true
  configuration:
    extendedIndentAfterOperators: false
    extendedIndentBeforeDot: false

These parameters are true by default, so diktat expects 8 spaces after = and 8 spaces before each dot-qualified call. Does it help or are there still unexpected errors?

Regarding WRONG_NEWLINES - these errors are correct according to diktat code style, see rule about line breaks. So, .filterIsInstance call should start on a new line because this is a chain of dot-qualified calls, and same goes for the line }.catch { logger.catching(it) } - diktat tells you to insert a line break before .catch too.

saveourtool / diktat