introduce param object: pass substitution around which won't be available after method signature is changed (IDEA-154208)

java/java-tests/testData/refactoring/introduceParameterObject/typeParametersWithSubstitution/after/Param.java

@@ -0,0 +1,13 @@
+import java.util.List;
+
+public class Param<T> {
+    private final List<T> y;
+
+    public Param(List<T> y) {
+        this.y = y;
+    }
+
+    public List<T> getY() {
+        return y;
+    }
+}

java/java-tests/testData/refactoring/introduceParameterObject/typeParametersWithSubstitution/after/Test.java

@@ -0,0 +1,11 @@
+import java.util.List;
+
+public class Test {
+  public static <T> String foo(Param<T> param) {
+    return null;
+  }
+
+  void bar(List<Integer> list) {
+    System.out.println(foo(new Param<>(list)));
+  }
+}

java/java-tests/testData/refactoring/introduceParameterObject/typeParametersWithSubstitution/before/Test.java

@@ -0,0 +1,12 @@
+import java.util.Collection;
+import java.util.List;
+
+public class Test {
+  public static <T> String foo(List<T> y) {
+    return null;
+  }
+
+  void bar(List<Integer> list) {
+    System.out.println(foo(list));
+  }
+}

java/java-tests/testSrc/com/intellij/refactoring/IntroduceParameterObjectTest.java

@@ -22,7 +22,9 @@ package com.intellij.refactoring;
 
 import com.intellij.JavaTestUtil;
 import com.intellij.openapi.fileEditor.FileDocumentManager;
+import com.intellij.openapi.roots.LanguageLevelProjectExtension;
 import com.intellij.openapi.vfs.LocalFileSystem;
+import com.intellij.pom.java.LanguageLevel;
 import com.intellij.psi.*;
 import com.intellij.psi.search.GlobalSearchScope;
 import com.intellij.refactoring.changeSignature.JavaMethodDescriptor;
@@ -132,6 +134,18 @@ public class IntroduceParameterObjectTest extends MultiFileTestCase{
     doTest();
   }
 
+  public void testTypeParametersWithSubstitution() throws Exception {
+    final LanguageLevelProjectExtension projectExtension = LanguageLevelProjectExtension.getInstance(getProject());
+    final LanguageLevel oldLevel = projectExtension.getLanguageLevel();
+    try {
+      projectExtension.setLanguageLevel(LanguageLevel.HIGHEST);
+      doTest();
+    }
+    finally {
+      projectExtension.setLanguageLevel(oldLevel);
+    }
+  }
+
   public void testSameTypeAndVarargs() throws Exception {
     doTest(false, false, method -> {
       final PsiParameter[] parameters = method.getParameterList().getParameters();