search for method references during constructor search (IDEA-92804)

java/java-indexing-impl/src/com/intellij/psi/impl/search/ConstructorReferencesSearchHelper.java

@@ -1,6 +1,7 @@
 package com.intellij.psi.impl.search;
 
 import com.intellij.openapi.util.TextRange;
+import com.intellij.pom.java.LanguageLevel;
 import com.intellij.psi.*;
 import com.intellij.psi.impl.light.LightMemberReference;
 import com.intellij.psi.search.PsiSearchScopeUtil;
@@ -8,6 +9,7 @@ import com.intellij.psi.search.SearchRequestCollector;
 import com.intellij.psi.search.SearchScope;
 import com.intellij.psi.search.searches.ClassInheritorsSearch;
 import com.intellij.psi.search.searches.ReferencesSearch;
+import com.intellij.psi.util.PsiUtil;
 import com.intellij.util.PairProcessor;
 import com.intellij.util.Processor;
 
@@ -72,6 +74,24 @@ public class ConstructorReferencesSearchHelper {
     };
 
     ReferencesSearch.searchOptimized(aClass, searchScope, ignoreAccessScope, collector, true, processor1);
+    if (PsiUtil.getLanguageLevel(aClass).isAtLeast(LanguageLevel.JDK_1_8)) {
+      ReferencesSearch.search(aClass).forEach(new Processor<PsiReference>() {
+        @Override
+        public boolean process(PsiReference reference) {
+          final PsiElement element = reference.getElement();
+          if (element != null) {
+            final PsiElement parent = element.getParent();
+            if (parent instanceof PsiMethodReferenceExpression &&
+                ((PsiMethodReferenceExpression)parent).getReferenceNameElement() instanceof PsiKeyword) {
+              if (((PsiMethodReferenceExpression)parent).isReferenceTo(constructor)) {
+                processor.process(reference);
+              }
+            }
+          }
+          return true;
+        }
+      });
+    }
 
     final boolean constructorCanBeCalledImplicitly = constructor.getParameterList().getParametersCount() == 0;
     // search usages like "this(..)"

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/methodRef/findUsages/ConstructorUsages.java

@@ -0,0 +1,11 @@
+class ConstructorUsages {
+  ConstructorUsages() {
+  }
+
+  void foo() {
+    BlahBlah<ConstructorUsages> blahBlah = ConstructorUsages::new;
+  }
+}
+interface BlahBlah<T> {
+        T foo();
+}

java/java-tests/testSrc/com/intellij/codeInsight/daemon/lambda/MethodReferencesFindUsagesTest.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2000-2012 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.intellij.codeInsight.daemon.lambda;
+
+import com.intellij.codeInsight.daemon.LightDaemonAnalyzerTestCase;
+import com.intellij.psi.PsiClass;
+import com.intellij.psi.PsiMethod;
+import com.intellij.psi.PsiReference;
+import com.intellij.psi.search.searches.MethodReferencesSearch;
+import org.jetbrains.annotations.NonNls;
+
+import java.util.Collection;
+
+/**
+ * User: anna
+ * Date: 10/15/12
+ */
+public class MethodReferencesFindUsagesTest extends LightDaemonAnalyzerTestCase {
+  @NonNls static final String BASE_PATH = "/codeInsight/daemonCodeAnalyzer/lambda/methodRef/findUsages/";
+  
+  
+
+  public void testConstructorUsages() throws Exception {
+    final String testName = getTestName(false);
+    configureByFile(BASE_PATH + testName + ".java");
+
+    final PsiClass aClass = getJavaFacade().findClass(testName);
+    assertNotNull(aClass);
+    final PsiMethod[] constructors = aClass.getConstructors();
+    assertEquals(constructors.length, 1);
+    Collection<PsiReference> references = MethodReferencesSearch.search(constructors[0]).findAll();
+    assertEquals(1, references.size());
+  }
+}