FunctionalExpressionUtils#getFunctionalExpressionType

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

@@ -1601,9 +1601,7 @@ public class SimplifyStreamApiCallChainsInspection extends AbstractBaseJavaLocal
             reversed = true;
           } else {
             if (maybeComparator == null) return null;
-            PsiType comparatorType = maybeComparator instanceof PsiFunctionalExpression
-                             ? ((PsiFunctionalExpression)maybeComparator).getFunctionalInterfaceType()
-                             : maybeComparator.getType();
+            PsiType comparatorType = FunctionalExpressionUtils.getFunctionalExpressionType(maybeComparator);
             if (!InheritanceUtil.isInheritor(comparatorType, JAVA_UTIL_COMPARATOR)) return null;
             comparator = maybeComparator.getText();
           }

java/java-impl/src/com/intellij/codeInspection/streamToLoop/FunctionHelper.java

@@ -15,6 +15,7 @@ import com.intellij.refactoring.util.LambdaRefactoringUtil;
 import com.intellij.util.ArrayUtil;
 import com.siyeh.ig.psiutils.EquivalenceChecker;
 import com.siyeh.ig.psiutils.ExpressionUtils;
+import com.siyeh.ig.psiutils.FunctionalExpressionUtils;
 import com.siyeh.ig.psiutils.MethodCallUtils;
 import one.util.streamex.EntryStream;
 import one.util.streamex.StreamEx;
@@ -133,9 +134,7 @@ abstract class FunctionHelper {
   @Nullable
   static FunctionHelper create(PsiExpression expression, int paramCount, boolean allowReturns) {
     if(expression == null) return null;
-    PsiType type = expression instanceof PsiFunctionalExpression
-                   ? ((PsiFunctionalExpression)expression).getFunctionalInterfaceType()
-                   : expression.getType();
+    PsiType type = FunctionalExpressionUtils.getFunctionalExpressionType(expression);
     if(!(type instanceof PsiClassType)) return null;
     PsiMethod interfaceMethod = LambdaUtil.getFunctionalInterfaceMethod(type);
     if (interfaceMethod == null || interfaceMethod.getParameterList().getParametersCount() != paramCount) return null;

plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/bugs/SuspiciousToArrayCallInspection.java

@@ -22,6 +22,7 @@ import com.intellij.psi.util.PsiUtil;
 import com.siyeh.InspectionGadgetsBundle;
 import com.siyeh.ig.BaseInspection;
 import com.siyeh.ig.BaseInspectionVisitor;
+import com.siyeh.ig.psiutils.FunctionalExpressionUtils;
 import com.siyeh.ig.psiutils.StreamApiUtil;
 import com.siyeh.ig.psiutils.TypeUtils;
 import org.jetbrains.annotations.NonNls;
@@ -97,13 +98,7 @@ public class SuspiciousToArrayCallInspection extends BaseInspection {
     }
 
     private static PsiType getIntFunctionParameterType(PsiExpression argument) {
-      PsiType argumentType;
-      if (argument instanceof PsiFunctionalExpression) {
-        argumentType = ((PsiFunctionalExpression)argument).getFunctionalInterfaceType();
-      }
-      else {
-        argumentType = argument.getType();
-      }
+      PsiType argumentType = FunctionalExpressionUtils.getFunctionalExpressionType(argument);
       return PsiUtil.substituteTypeParameter(argumentType, "java.util.function.IntFunction", 0, false);
     }
 

plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/psiutils/FunctionalExpressionUtils.java

@@ -106,4 +106,22 @@ public class FunctionalExpressionUtils {
     }
     return null;
   }
+
+  /**
+   * Returns the type of functional expression (not {@link PsiLambdaExpressionType} or {@link PsiMethodReferenceType},
+   * but actual functional interface type).
+   *
+   * @param expression expression to find the type of.
+   * @return type of functional expression.
+   */
+  public static PsiType getFunctionalExpressionType(PsiExpression expression) {
+    PsiType argumentType;
+    if (expression instanceof PsiFunctionalExpression) {
+      argumentType = ((PsiFunctionalExpression)expression).getFunctionalInterfaceType();
+    }
+    else {
+      argumentType = expression.getType();
+    }
+    return argumentType;
+  }
 }

plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/psiutils/TypeUtils.java

@@ -133,9 +133,7 @@ public class TypeUtils {
     if (expression == null) {
       return null;
     }
-    final PsiType type = expression instanceof PsiFunctionalExpression
-                         ? ((PsiFunctionalExpression)expression).getFunctionalInterfaceType()
-                         : expression.getType();
+    final PsiType type = FunctionalExpressionUtils.getFunctionalExpressionType(expression);
     if (type == null) {
       return null;
     }