TYPE: implement SelfManagingCommenter

[Kobzol]

This PR solves #5388 with a pretty heavyweight solution of implementing SelfManagingCommenter. The implementation is pretty basic, but it passes all the original RsCommenter tests and some new ones that I have added.

It seems to work for basic use cases, if you can find some counter-examples where it breaks, let me know and I'll add them to the test suite.

Fixes: #5388

[vlad20012]

👍 It looks much simpler than I expected! Thanks!

[Kobzol]

Added test for space after line comment settings and fixed the rest. Should getCommentPrefix respect the space after line comment settings and return // if it's turned on? It seems to work if I just return // everytime.

There's something weird with the test move caret after commenting empty line test. Instead of

//<caret>
fn foo() {}

it returns

//
<caret>fn foo() {}

even though when I try it in the IDE, it behaves correctly.

[vlad20012]

Should getCommentPrefix respect the space after line comment settings and return // if it's turned on?

It looks like no, simple // is enough

There's something weird with the test move caret after commenting empty line test

This was tricky, but I found the reason. There is a mutable state in ActionManagerImpl that outlives a test. It's info about previous run action - myPrevPerformedActionId. Then it's used in CommentByLineCommentHandler.invoke - see startingNewLineComment condition. I don't know is it a bug or a feature of the test framework.

I've changed the code of checkOption like this and looks like it works as expected now:

private fun checkOption(optionProperty: KMutableProperty0<Boolean>,
                            @Language("Rust") before: String,
                            @Language("Rust") afterOn: String,
                            @Language("Rust") afterOff: String,
                            actionId: String,
                            trimIndent: Boolean = true) {
        val initialValue = optionProperty.get()
        optionProperty.set(true)
        try {
            checkEditorAction(before, afterOn, actionId, trimIndent = trimIndent)
            resetActionManagerState()
            optionProperty.set(false)
            checkEditorAction(before, afterOff, actionId, trimIndent = trimIndent)
            resetActionManagerState()
        } finally {
            optionProperty.set(initialValue)
        }
    }

    private fun settings() = CodeStyle.getSettings(project).getCommonSettings(RsLanguage)

    /**
     * Resets [com.intellij.openapi.actionSystem.impl.ActionManagerImpl.myPrevPerformedActionId].
     * Otherwise it affect [com.intellij.codeInsight.generation.CommentByLineCommentHandler.invoke]
     * (see `startingNewLineComment` condition there).
     */
    private fun resetActionManagerState() {
        myFixture.performEditorAction(EMPTY_ACTION_ID)
    }

    override fun setUp() {
        super.setUp()
        ActionManager.getInstance().registerAction(EMPTY_ACTION_ID, EmptyAction.createEmptyAction("empty", null, true))
    }

    override fun tearDown() {
        try {
            super.tearDown()
        } finally {
            ActionManager.getInstance().unregisterAction(EMPTY_ACTION_ID)
        }
    }

    companion object {
        private const val EMPTY_ACTION_ID = "!!!EmptyAction"
    }

[Kobzol]

Thank you! It works locally, but it seems that CI is not happy for some reason..

[vlad20012]

Hmm
bors try

[bors]

try

Build failed:

• continuous-integration/appveyor/branch

[vlad20012]

Let's also add this:

override fun checkEditorAction(before: String, after: String, actionId: String, trimIndent: Boolean, testmark: Testmark?) {
        super.checkEditorAction(before, after, actionId, trimIndent, testmark)
        resetActionManagerState()

    }

Looks like it fails on CI because of different test order when tests are run by Gradle

[vlad20012]

👍
bors r+

[bors]

Build succeeded:

• continuous-integration/appveyor/branch
• continuous-integration/travis-ci/push