IDEA-179490 "Can be replaced with single expression in functional style" in Java fails when field name matches class name

java/java-impl/src/com/intellij/codeInspection/OptionalIsPresentInspection.java

@@ -32,6 +32,8 @@ import com.intellij.psi.impl.PsiDiamondTypeUtil;
 import com.intellij.psi.util.PsiTreeUtil;
 import com.intellij.psi.util.PsiTypesUtil;
 import com.intellij.psi.util.PsiUtil;
+import com.intellij.util.ArrayUtil;
+import com.intellij.util.ObjectUtils;
 import com.siyeh.ig.psiutils.BoolUtils;
 import com.siyeh.ig.psiutils.CommentTracker;
 import com.siyeh.ig.psiutils.ControlFlowUtils;
@@ -206,10 +208,8 @@ public class OptionalIsPresentInspection extends BaseJavaBatchLocalInspectionToo
     PsiType type = optionalVariable.getType();
     JavaCodeStyleManager javaCodeStyleManager = JavaCodeStyleManager.getInstance(trueValue.getProject());
     SuggestedNameInfo info = javaCodeStyleManager.suggestVariableName(VariableKind.PARAMETER, null, null, type);
-    if (info.names.length == 0) {
-      info = javaCodeStyleManager.suggestVariableName(VariableKind.PARAMETER, "value", null, type);
-    }
-    String paramName = javaCodeStyleManager.suggestUniqueVariableName(info, trueValue, true).names[0];
+    String baseName = ObjectUtils.coalesce(ArrayUtil.getFirstElement(info.names), "value");
+    String paramName = javaCodeStyleManager.suggestUniqueVariableName(baseName, trueValue, true);
     if(trueValue instanceof PsiExpressionStatement) {
       trueValue = ((PsiExpressionStatement)trueValue).getExpression();
     }

java/java-psi-api/src/com/intellij/psi/codeStyle/JavaCodeStyleManager.java

@@ -179,7 +179,8 @@ public abstract class JavaCodeStyleManager {
   public abstract String propertyNameToVariableName(@NonNls @NotNull String propertyName, @NotNull VariableKind variableKind);
 
   /**
-   * Suggests a unique name for the variable used at the specified location.
+   * Suggests a unique name for the variable used at the specified location. The returned name is guaranteed to not shadow
+   * the existing name.
    *
    * @param baseName    the base name for the variable.
    * @param place       the location where the variable will be used.
@@ -190,12 +191,13 @@ public abstract class JavaCodeStyleManager {
   public abstract String suggestUniqueVariableName(@NonNls @NotNull String baseName, PsiElement place, boolean lookForward);
 
   /**
-   * Suggests a unique name for the variable used at the specified location.
+   * Suggests a unique names for the variable used at the specified location. The resulting name info may contain names which
+   * shadow existing names.
    *
    * @param baseNameInfo the base name info for the variable.
    * @param place        the location where the variable will be used.
    * @param lookForward  if true, the existing variables are searched in both directions; if false - only backward
-   * @return the generated unique name
+   * @return the generated unique name info.
    */
   @NotNull
   public SuggestedNameInfo suggestUniqueVariableName(@NotNull SuggestedNameInfo baseNameInfo,

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/optionalIsPresent/afterFieldNameConflict.java

@@ -0,0 +1,18 @@
+// "Replace Optional.isPresent() condition with functional style expression" "true"
+
+import java.util.Optional;
+
+public class Test {
+  private Power power;
+
+  interface Power {
+    static Optional<Power> parseValue(String value) {
+      return Optional.empty();
+    }
+  }
+
+  void testOpt(String powerValue) {
+    Optional<Power> optPower = Power.parseValue(powerValue);
+      optPower.ifPresent(power1 -> power = power1);
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/optionalIsPresent/beforeFieldNameConflict.java

@@ -0,0 +1,20 @@
+// "Replace Optional.isPresent() condition with functional style expression" "true"
+
+import java.util.Optional;
+
+public class Test {
+  private Power power;
+
+  interface Power {
+    static Optional<Power> parseValue(String value) {
+      return Optional.empty();
+    }
+  }
+
+  void testOpt(String powerValue) {
+    Optional<Power> optPower = Power.parseValue(powerValue);
+    if (optPower<caret>.isPresent()) {
+      power = optPower.get();
+    }
+  }
+}