StaticPseudoFunctionalStyleMethodInspection: doesn't throw exception when lambda is variable

java/java-impl/src/com/intellij/codeInspection/java18StreamApi/PseudoLambdaReplaceTemplate.java

@@ -449,6 +449,12 @@ class PseudoLambdaReplaceTemplate {
       final String methodName = functionalInterfaceMethod.getName();
       return JavaPsiFacade.getElementFactory(expression.getProject()).createExpressionFromText(expression.getText() + "::" + methodName, null);
     }
+    if (expression instanceof PsiReferenceExpression) {
+      final PsiType expressionType = expression.getType();
+      final PsiMethod method = LambdaUtil.getFunctionalInterfaceMethod(expressionType);
+      LOG.assertTrue(method != null);
+      return JavaPsiFacade.getElementFactory(expression.getProject()).createExpressionFromText(expression.getText() + "::" + method.getName(), null);
+    }
     return AnonymousCanBeLambdaInspection.replacePsiElementWithLambda(expression, true);
   }
 

java/java-tests/testData/inspection/lambdaLibsStatic/lambdaIsVariable/test.java

@@ -0,0 +1,24 @@
+import com.google.common.collect.Iterables;
+import com.google.common.base.Function;
+
+import java.lang.String;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.stream.Collectors;
+
+class c {
+  void m() {
+    final Function<String, String> function = (Function<String, String>)new Function<String, String>() {
+      @Override
+      public String apply(String input) {
+        Collectors c;
+        ArrayList l;
+        System.out.println(input);
+        //do something
+        int i = 1;
+        return input;
+      }
+    };
+    Iterables.transfo<caret>rm(Collections.emptyList(), function);
+  }
+}

java/java-tests/testData/inspection/lambdaLibsStatic/lambdaIsVariable/test_after.java

@@ -0,0 +1,24 @@
+import com.google.common.collect.Iterables;
+import com.google.common.base.Function;
+
+import java.lang.String;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.stream.Collectors;
+
+class c {
+  void m() {
+    final Function<String, String> function = (Function<String, String>)new Function<String, String>() {
+      @Override
+      public String apply(String input) {
+        Collectors c;
+        ArrayList l;
+        System.out.println(input);
+        //do something
+        int i = 1;
+        return input;
+      }
+    };
+    Collections.<String>emptyList().stream().map(function::apply).collect(Collectors.toList());
+  }
+}

java/java-tests/testSrc/com/intellij/codeInspection/StaticPseudoFunctionalStyleMethodTest.java

@@ -108,6 +108,10 @@ public class StaticPseudoFunctionalStyleMethodTest extends JavaCodeInsightFixtur
     doTest();
   }
 
+  public void testLambdaIsVariable() {
+    doTest();
+  }
+
   public void _testReplaceWithMethodReference() {
     doTest();
   }