Java: do not change too much on migrating expression type used in compound string assignment (IDEA-310441)

GitOrigin-RevId: d0c2bb8d47427f266c1b87c36bccb8e500dea366

java/typeMigration/test/com/intellij/refactoring/TypeMigrationTest.java

@@ -1,3 +1,4 @@
+// Copyright 2000-2023 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.intellij.refactoring;
 
 import com.intellij.application.options.CodeStyle;
@@ -39,6 +40,10 @@ public class TypeMigrationTest extends TypeMigrationTestBase {
     super.tearDown();
   }
 
+  public void testStringCompoundAssignment() {
+    doTestFirstParamType("x", PsiTypes.longType());
+  }
+
   public void testT07() {
     doTestFieldType("f",
                     myFactory.createTypeFromText("java.lang.Integer", null).createArrayType());

java/typeMigration/testData/refactoring/typeMigration/stringCompoundAssignment/after/Test.items

@@ -0,0 +1,8 @@
+Types:
+PsiParameter:i : long
+PsiReferenceExpression:i : long
+
+Conversions:
+
+New expression type changes:
+Fails:

java/typeMigration/testData/refactoring/typeMigration/stringCompoundAssignment/after/Test.java

@@ -0,0 +1,7 @@
+class Test {
+
+  public void x(long i) {
+    String s = "";
+    s += i;
+  }
+}

java/typeMigration/testData/refactoring/typeMigration/stringCompoundAssignment/before/Test.java

@@ -0,0 +1,7 @@
+class Test {
+
+  public void x(int i) {
+    String s = "";
+    s += i;
+  }
+}