Java: Ignore bare method expression (without parentheses) when matching potential parameters of extracted method (IDEA-194264)

java/java-analysis-impl/src/com/intellij/refactoring/util/duplicates/Match.java

@@ -126,6 +126,8 @@ public final class Match {
     final List<PsiElement> currentValue = myParameterValues.get(psiVariable);
     final boolean isVararg = psiVariable instanceof PsiParameter && ((PsiParameter)psiVariable).isVarArgs();
     if (!(value instanceof PsiExpression)) return false;
+    final PsiElement parent = value.getParent();
+    if (parent instanceof PsiMethodCallExpression && value == ((PsiMethodCallExpression)parent).getMethodExpression()) return false;
     final PsiType type = ((PsiExpression)value).getType();
     final PsiType parameterType = parameter.getType();
     if (type == null) return false;

java/java-tests/testData/refactoring/extractMethod/OneVariableExpression.java

@@ -0,0 +1,12 @@
+import java.util.List;
+
+class C {
+    void m(List<String> list) {
+        int i = 0;
+        System.out.println(<selection>i</selection>);
+
+        if (list.size() > 0) {
+            System.out.println(list.size());
+        }
+    }
+}

java/java-tests/testData/refactoring/extractMethod/OneVariableExpression_after.java

@@ -0,0 +1,16 @@
+import java.util.List;
+
+class C {
+    void m(List<String> list) {
+        int i = 0;
+        System.out.println(newMethod(i));
+
+        if (list.size() > 0) {
+            System.out.println(list.size());
+        }
+    }
+
+    private int newMethod(int i) {
+        return i;
+    }
+}

java/java-tests/testData/refactoring/extractMethod15/CodeDuplicatesWithMultOccurences_after.java

@@ -1,7 +1,7 @@
 class Test {
     void t(java.util.Map<String, String> m) {
         String f = "";
-        System.out.println("f = " + newMethod(f) + ", " + newMethod(newMethod(f)));
+        System.out.println("f = " + newMethod(f) + ", " + m.get(newMethod(f)));
     }
 
     private String newMethod(String f) {

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

@@ -1321,6 +1321,10 @@ public class ExtractMethodTest extends LightCodeInsightTestCase {
     doDuplicatesTest();
   }
 
+  public void testOneVariableExpression() throws Exception {
+    doDuplicatesTest();
+  }
+
   public void testInterfaceMethodVisibility() throws Exception {
     final String doesNotExist = "foo.bar.baz.DoesNotExist";
     final NullableNotNullManager nullManager = NullableNotNullManager.getInstance(getProject());