FIR IDE: add remove modifier quick fixes

idea/idea-fir/src/org/jetbrains/kotlin/idea/quickfix/MainKtQuickFixRegistrar.kt

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.idea.quickfix
+
+import com.intellij.psi.PsiElement
+import org.jetbrains.kotlin.idea.frontend.api.fir.diagnostics.KtFirDiagnostic
+import org.jetbrains.kotlin.idea.quickfix.fixes.ChangeTypeQuickFix
+import org.jetbrains.kotlin.lexer.KtToken
+import org.jetbrains.kotlin.lexer.KtTokens
+import org.jetbrains.kotlin.psi.KtCallableDeclaration
+import org.jetbrains.kotlin.psi.KtModifierListOwner
+
+class MainKtQuickFixRegistrar : KtQuickFixRegistrar() {
+    private val modifiers = KtQuickFixesListBuilder.register {
+        register<PsiElement, KtFirDiagnostic.RedundantModifier>(RemoveModifierFix.createRemoveModifierFactory(isRedundant = true))
+        register<PsiElement, KtFirDiagnostic.IncompatibleModifiers>(RemoveModifierFix.createRemoveModifierFactory(isRedundant = false))
+        register<PsiElement, KtFirDiagnostic.RepeatedModifier>(RemoveModifierFix.createRemoveModifierFactory(isRedundant = false))
+        register<PsiElement, KtFirDiagnostic.DeprecatedModifierPair>(RemoveModifierFix.createRemoveModifierFactory(isRedundant = true))
+        register<PsiElement, KtFirDiagnostic.TypeParametersInEnum>(RemoveModifierFix.createRemoveModifierFactory(isRedundant = true))
+        register<KtModifierListOwner, KtFirDiagnostic.RedundantOpenInInterface>(
+            RemoveModifierFix.createRemoveModifierFromListOwnerFactoryByModifierListOwner(
+                modifier = KtTokens.OPEN_KEYWORD,
+                isRedundant = true
+            )
+        )
+    }
+
+    override val list: KtQuickFixesList = KtQuickFixesList.createCombined(
+        modifiers,
+    )
+}

idea/src/org/jetbrains/kotlin/idea/quickfix/RemoveModifierFix.kt

@@ -53,13 +53,17 @@ class RemoveModifierFix(
         fun createRemoveModifierFromListOwnerFactory(
             modifier: KtModifierKeywordToken,
             isRedundant: Boolean = false
-        ): QuickFixesPsiBasedFactory {
-            return object : QuickFixesPsiBasedFactory() {
-                override fun createQuickFix(psiElement: PsiElement): RemoveModifierFix? {
-                    val modifierListOwner = PsiTreeUtil.getParentOfType(psiElement, KtModifierListOwner::class.java, false) ?: return null
-                    return RemoveModifierFix(modifierListOwner, modifier, isRedundant)
-                }
-            }
+        ): QuickFixesPsiBasedFactory<PsiElement> =
+            createRemoveModifierFromListOwnerFactoryByModifierListOwner(
+                modifier,
+                isRedundant
+            ).coMap { PsiTreeUtil.getParentOfType(it, KtModifierListOwner::class.java, false) }
+
+        fun createRemoveModifierFromListOwnerFactoryByModifierListOwner(
+            modifier: KtModifierKeywordToken,
+            isRedundant: Boolean = false
+        ) = quickFixesPsiBasedFactory<KtModifierListOwner> {
+            listOf(RemoveModifierFix(it, modifier, isRedundant))
         }
 
         fun createRemoveModifierFactory(isRedundant: Boolean = false): QuickFixesPsiBasedFactory<PsiElement> {