check if constructor already contains field assignment before add new one (IDEA-69792)

java/java-impl/src/com/intellij/codeInsight/daemon/impl/quickfix/CreateConstructorParameterFromFieldFix.java

@@ -15,7 +15,6 @@
  */
 package com.intellij.codeInsight.daemon.impl.quickfix;
 
-import com.intellij.codeInsight.CodeInsightBundle;
 import com.intellij.codeInsight.CodeInsightUtilBase;
 import com.intellij.codeInsight.daemon.QuickFixBundle;
 import com.intellij.codeInsight.daemon.impl.analysis.HighlightControlFlowUtil;
@@ -30,12 +29,17 @@ import com.intellij.openapi.util.Comparing;
 import com.intellij.openapi.util.Computable;
 import com.intellij.psi.*;
 import com.intellij.psi.impl.source.jsp.jspJava.JspClass;
+import com.intellij.psi.search.LocalSearchScope;
+import com.intellij.psi.search.searches.ReferencesSearch;
+import com.intellij.psi.util.PsiTreeUtil;
 import com.intellij.psi.util.PsiTypesUtil;
+import com.intellij.psi.util.PsiUtil;
 import com.intellij.refactoring.util.RefactoringUtil;
 import com.intellij.util.ArrayUtil;
 import com.intellij.util.IncorrectOperationException;
 import org.jetbrains.annotations.NotNull;
 
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Comparator;
 import java.util.List;
@@ -99,11 +103,12 @@ public class CreateConstructorParameterFromFieldFix implements IntentionAction {
         }
       }
     });
-    if (constructors.length > 1) {
-
-      final PsiMethodMember[] members = new PsiMethodMember[constructors.length];
-      for (int i = 0, constructorsLength = constructors.length; i < constructorsLength; i++) {
-        members[i] = new PsiMethodMember(constructors[i]);
+    final ArrayList<PsiMethod> constrs = filterConstructorsIfFieldAlreadyAssigned(constructors);
+    if (constrs.size() > 1) {
+      final PsiMethodMember[] members = new PsiMethodMember[constrs.size()];
+      int i = 0;
+      for (PsiMethod constructor : constrs) {
+        members[i++] = new PsiMethodMember(constructor);
       }
       final List<PsiMethodMember> elements;
       if (ApplicationManager.getApplication().isUnitTestMode()) {
@@ -120,11 +125,25 @@ public class CreateConstructorParameterFromFieldFix implements IntentionAction {
         if (!addParameterToConstructor(project, file, editor, member.getElement())) break;
       }
 
-    } else {
-      addParameterToConstructor(project, file, editor, constructors[0]);
+    } else if (!constrs.isEmpty()) {
+      addParameterToConstructor(project, file, editor, constrs.get(0));
     }
   }
 
+  private ArrayList<PsiMethod> filterConstructorsIfFieldAlreadyAssigned(PsiMethod[] constructors) {
+    final ArrayList<PsiMethod> result = new ArrayList<PsiMethod>(Arrays.asList(constructors));
+    for (PsiReference reference : ReferencesSearch.search(getField(), new LocalSearchScope(constructors))) {
+      final PsiElement element = reference.getElement();
+      if (element instanceof PsiReferenceExpression && PsiUtil.isOnAssignmentLeftHand((PsiExpression)element)) {
+        final PsiExpression rExpression = ((PsiAssignmentExpression)element.getParent()).getRExpression();
+        if (rExpression instanceof PsiReferenceExpression && ((PsiReferenceExpression)rExpression).resolve() instanceof PsiParameter) {
+          result.remove(PsiTreeUtil.getParentOfType(element, PsiMethod.class));
+        }
+      }
+    }
+    return result;
+  }
+
   private boolean addParameterToConstructor(final Project project, final PsiFile file, final Editor editor, PsiMethod constructor) throws IncorrectOperationException {
     final PsiParameter[] parameters = constructor.getParameterList().getParameters();
     PsiExpression[] expressions = new PsiExpression[parameters.length+1];

java/java-impl/src/com/intellij/codeInsight/intention/impl/AssignFieldFromParameterAction.java

@@ -102,7 +102,7 @@ public class AssignFieldFromParameterAction extends BaseIntentionAction {
     PsiClass targetClass = method.getContainingClass();
 
     String stmtText = fieldName + " = " + parameterName + ";";
-    if (Comparing.strEqual(fieldName, parameterName)) {
+    if (Comparing.strEqual(fieldName, parameterName) || JavaPsiFacade.getInstance(project).getResolveHelper().resolveReferencedVariable(fieldName, methodBody) != field) {
       @NonNls String prefix = isMethodStatic ? targetClass.getName() == null ? "" : targetClass.getName() + "." : "this.";
       stmtText = prefix + stmtText;
     }

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/createConstructorParameterFromField/afterAlreadyAssigned.java

@@ -0,0 +1,12 @@
+// "Add constructor parameter" "true"
+class A {
+  private final String text;
+
+  public Foo(String text) {
+    this.text = text;
+  }
+
+  public Foo(int i, String text) {
+      this.text = text;
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/createConstructorParameterFromField/beforeAlreadyAssigned.java

@@ -0,0 +1,11 @@
+// "Add constructor parameter" "true"
+class A {
+  private final String te<caret>xt;
+
+  public Foo(String text) {
+    this.text = text;
+  }
+
+  public Foo(int i) {
+  }
+}