Fix KNPE in different "Generate members" for expect class

#KT-27595 Fixed

idea/src/org/jetbrains/kotlin/idea/actions/generate/KotlinGenerateEqualsAndHashcodeAction.kt

@@ -250,7 +250,7 @@ class KotlinGenerateEqualsAndHashcodeAction : KotlinGenerateMemberActionBase<Kot
                 append("return true")
             }
 
-            equalsFun.bodyExpression!!.replace(KtPsiFactory(project).createBlock(bodyText))
+            equalsFun.replaceBody { KtPsiFactory(project).createBlock(bodyText) }
 
             return equalsFun
         }
@@ -311,7 +311,7 @@ class KotlinGenerateEqualsAndHashcodeAction : KotlinGenerateMemberActionBase<Kot
                 }.toString()
             } else "return $initialValue"
 
-            hashCodeFun.bodyExpression!!.replace(KtPsiFactory(project).createBlock(bodyText))
+            hashCodeFun.replaceBody { KtPsiFactory(project).createBlock(bodyText) }
 
             return hashCodeFun
         }

idea/src/org/jetbrains/kotlin/idea/actions/generate/KotlinGenerateMemberActionBase.kt

@@ -24,14 +24,17 @@ import com.intellij.openapi.fileEditor.FileDocumentManager
 import com.intellij.openapi.project.Project
 import com.intellij.psi.PsiFile
 import org.jetbrains.kotlin.idea.util.application.executeWriteCommand
-import org.jetbrains.kotlin.psi.KtClassOrObject
-import org.jetbrains.kotlin.psi.KtDeclaration
+import org.jetbrains.kotlin.psi.*
 
 abstract class KotlinGenerateMemberActionBase<Info : Any> : KotlinGenerateActionBase() {
     protected abstract fun prepareMembersInfo(klass: KtClassOrObject, project: Project, editor: Editor?): Info?
 
     protected abstract fun generateMembers(project: Project, editor: Editor?, info: Info): List<KtDeclaration>
 
+    protected fun KtNamedFunction.replaceBody(generateBody: () -> KtExpression) {
+        bodyExpression?.replace(generateBody())
+    }
+
     override fun invoke(project: Project, editor: Editor, file: PsiFile) {
         if (!CodeInsightUtilBase.prepareEditorForWrite(editor)) return
         if (!FileDocumentManager.getInstance().requestWriting(editor.document, project)) return

idea/src/org/jetbrains/kotlin/idea/actions/generate/KotlinGenerateToStringAction.kt

@@ -181,7 +181,9 @@ class KotlinGenerateToStringAction : KotlinGenerateMemberActionBase<KotlinGenera
     private fun generateToString(targetClass: KtClassOrObject, info: Info): KtNamedFunction? {
         val superToString = info.classDescriptor.getSuperClassOrAny().findDeclaredToString(true)!!
         return generateFunctionSkeleton(superToString, targetClass).apply {
-            bodyExpression!!.replace(KtPsiFactory(targetClass).createExpression("{\n${info.generator.generate(info)}\n}"))
+            replaceBody {
+                KtPsiFactory(targetClass).createExpression("{\n${info.generator.generate(info)}\n}")
+            }
         }
     }
 

idea/testData/multiModuleQuickFix/generateEqualsInExpect/common/common.kt

@@ -0,0 +1,9 @@
+// "Generate 'equals()'" "true"
+// TOOL: org.jetbrains.kotlin.idea.inspections.EqualsOrHashCodeInspection
+
+expect class With<caret>Constructor(x: Int, s: String) {
+    val x: Int
+    val s: String
+
+    override fun hashCode(): Int
+}

idea/testData/multiModuleQuickFix/generateEqualsInExpect/common/common.kt.after

@@ -0,0 +1,10 @@
+// "Generate 'equals()'" "true"
+// TOOL: org.jetbrains.kotlin.idea.inspections.EqualsOrHashCodeInspection
+
+expect class With<caret>Constructor(x: Int, s: String) {
+    val x: Int
+    val s: String
+
+    override fun hashCode(): Int
+    override fun equals(other: Any?): Boolean
+}

idea/testData/multiModuleQuickFix/generateEqualsInExpect/jvm/jvm.kt

@@ -0,0 +1 @@
+actual class WithConstructor(actual val x: Int, actual val s: String)

idea/testData/multiModuleQuickFix/generateEqualsInExpect/jvm/jvm.kt.after

@@ -0,0 +1 @@
+actual class WithConstructor(actual val x: Int, actual val s: String)

idea/testData/multiModuleQuickFix/generateHashCodeInExpect/common/common.kt

@@ -0,0 +1,9 @@
+// "Generate 'hashCode()'" "true"
+// TOOL: org.jetbrains.kotlin.idea.inspections.EqualsOrHashCodeInspection
+
+expect class With<caret>Constructor(x: Int, s: String) {
+    val x: Int
+    val s: String
+
+    override fun equals(other: Any?): Boolean
+}

idea/testData/multiModuleQuickFix/generateHashCodeInExpect/common/common.kt.after

@@ -0,0 +1,10 @@
+// "Generate 'hashCode()'" "true"
+// TOOL: org.jetbrains.kotlin.idea.inspections.EqualsOrHashCodeInspection
+
+expect class With<caret>Constructor(x: Int, s: String) {
+    val x: Int
+    val s: String
+
+    override fun equals(other: Any?): Boolean
+    override fun hashCode(): Int
+}

idea/testData/multiModuleQuickFix/generateHashCodeInExpect/jvm/jvm.kt

@@ -0,0 +1 @@
+actual class WithConstructor(actual val x: Int, actual val s: String)

idea/testData/multiModuleQuickFix/generateHashCodeInExpect/jvm/jvm.kt.after

@@ -0,0 +1 @@
+actual class WithConstructor(actual val x: Int, actual val s: String)

idea/tests/org/jetbrains/kotlin/idea/quickfix/QuickFixMultiModuleTestGenerated.java

@@ -259,6 +259,16 @@ public class QuickFixMultiModuleTestGenerated extends AbstractQuickFixMultiModul
         runTest("idea/testData/multiModuleQuickFix/functionTypeReceiverToParameterByImpl/");
     }
 
+    @TestMetadata("generateEqualsInExpect")
+    public void testGenerateEqualsInExpect() throws Exception {
+        runTest("idea/testData/multiModuleQuickFix/generateEqualsInExpect/");
+    }
+
+    @TestMetadata("generateHashCodeInExpect")
+    public void testGenerateHashCodeInExpect() throws Exception {
+        runTest("idea/testData/multiModuleQuickFix/generateHashCodeInExpect/");
+    }
+
     @TestMetadata("implementAbstractExpectMemberInheritedFromInterface")
     public void testImplementAbstractExpectMemberInheritedFromInterface() throws Exception {
         runTest("idea/testData/multiModuleQuickFix/implementAbstractExpectMemberInheritedFromInterface/");