From 22a45175bfa5dd2c827c8f38f6c9b5408d7573ff Mon Sep 17 00:00:00 2001
From: Louis Vignier <louis.vignier@jetbrains.com>
Date: Tue, 19 Jul 2022 19:15:42 +0200
Subject: [PATCH] [codeInspection] JoinDeclarationAndAssignmentFix: support
 preview

GitOrigin-RevId: ec78d6ebcd51dddc2c0516f12f3f6ee92dcef9bd
---
 ...JoinDeclarationAndAssignmentJavaInspection.java | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/java/java-impl-inspections/src/com/intellij/codeInspection/JoinDeclarationAndAssignmentJavaInspection.java b/java/java-impl-inspections/src/com/intellij/codeInspection/JoinDeclarationAndAssignmentJavaInspection.java
index fde4d544cac9..937a93c39d80 100644
--- a/java/java-impl-inspections/src/com/intellij/codeInspection/JoinDeclarationAndAssignmentJavaInspection.java
+++ b/java/java-impl-inspections/src/com/intellij/codeInspection/JoinDeclarationAndAssignmentJavaInspection.java
@@ -1,8 +1,9 @@
-// Copyright 2000-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+// Copyright 2000-2022 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.intellij.codeInspection;
 
 import com.intellij.codeInsight.FileModificationService;
 import com.intellij.codeInsight.editorActions.DeclarationJoinLinesHandler;
+import com.intellij.codeInsight.intention.preview.IntentionPreviewInfo;
 import com.intellij.java.JavaBundle;
 import com.intellij.openapi.application.WriteAction;
 import com.intellij.openapi.project.Project;
@@ -229,6 +230,17 @@ public class JoinDeclarationAndAssignmentJavaInspection extends AbstractBaseJava
         WriteAction.run(() -> DeclarationJoinLinesHandler.joinDeclarationAndAssignment(context.myVariable, context.myAssignment));
       }
     }
+
+    @Override
+    public @NotNull IntentionPreviewInfo generatePreview(@NotNull Project project, @NotNull ProblemDescriptor previewDescriptor) {
+      Context context = getContext(previewDescriptor.getPsiElement());
+      if (context != null) {
+        DeclarationJoinLinesHandler.joinDeclarationAndAssignment(context.myVariable, context.myAssignment);
+        return IntentionPreviewInfo.DIFF;
+      } else {
+        return IntentionPreviewInfo.EMPTY;
+      }
+    }
   }
 
   private static class Context {