Inline method: use StatementExtractor when removing unused parameters

IDEA-215429 Inline method with unused parameter causes uncompilable or unintended code

GitOrigin-RevId: d701c4a49b64202144c4d5ba80047d8f846f1767

java/java-impl/src/com/intellij/refactoring/inline/InlineMethodProcessor.java

@@ -33,6 +33,7 @@ import com.intellij.psi.search.LocalSearchScope;
 import com.intellij.psi.search.searches.OverridingMethodsSearch;
 import com.intellij.psi.search.searches.ReferencesSearch;
 import com.intellij.psi.util.*;
+import com.intellij.psi.util.InheritanceUtil;
 import com.intellij.refactoring.BaseRefactoringProcessor;
 import com.intellij.refactoring.RefactoringBundle;
 import com.intellij.refactoring.introduceParameter.Util;
@@ -47,10 +48,7 @@ import com.intellij.util.IncorrectOperationException;
 import com.intellij.util.JavaPsiConstructorUtil;
 import com.intellij.util.ObjectUtils;
 import com.intellij.util.containers.MultiMap;
-import com.siyeh.ig.psiutils.CommentTracker;
-import com.siyeh.ig.psiutils.ExpressionUtils;
-import com.siyeh.ig.psiutils.SideEffectChecker;
-import com.siyeh.ig.psiutils.VariableAccessUtils;
+import com.siyeh.ig.psiutils.*;
 import org.jetbrains.annotations.NonNls;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -989,12 +987,14 @@ public class InlineMethodProcessor extends BaseRefactoringProcessor {
 
     PsiExpression initializer = variable.getInitializer();
     if (firstRef == null) {
-      if (initializer != null && SideEffectChecker.mayHaveSideEffects(initializer)) {
-        RemoveUnusedVariableUtil.replaceElementWithExpression(initializer, PsiElementFactory.getInstance(myProject), variable);
-      }
-      else {
-        variable.getParent().delete();
+      PsiDeclarationStatement declaration = (PsiDeclarationStatement)variable.getParent();
+      if (initializer != null) {
+        List<PsiExpression> sideEffects = SideEffectChecker.extractSideEffectExpressions(initializer);
+        for (PsiStatement statement : StatementExtractor.generateStatements(sideEffects, initializer)) {
+          declaration.getParent().addBefore(statement, declaration);
+        }
       }
+      declaration.delete();
       return;
     }
 

java/java-tests/testData/refactoring/inlineMethod/UnusedParameter.java

@@ -0,0 +1,16 @@
+
+import java.util.Set;
+import java.util.Map;
+
+class Temp {
+  public Object foo(Set<String> bar) {
+    if (bar.size() < 2)
+      return <caret>abortWithCorruptDataError("" + bar.size()); // Inline this
+
+    return bar;
+  }
+
+  public static Map<String, Object> abortWithCorruptDataError(Object message) { // or online this
+    return null;
+  }
+}

java/java-tests/testData/refactoring/inlineMethod/UnusedParameter.java.after

@@ -0,0 +1,15 @@
+
+import java.util.Set;
+
+class Temp {
+  public Object foo(Set<String> bar) {
+    if (bar.size() < 2) {
+// Inline this
+        bar.size(); // or online this
+        return null;
+    }
+
+    return bar;
+  }
+
+}

java/java-tests/testSrc/com/intellij/java/refactoring/inline/InlineMethodTest.java

@@ -526,6 +526,10 @@ public class InlineMethodTest extends LightRefactoringTestCase {
   public void testInvertMethod() {
     doTest();
   }
+  
+  public void testUnusedParameter() {
+    doTest();
+  }
 
   @Override
   protected Sdk getProjectJDK() {