HighlightVisitorImpl: add standard quick-fixes for lambda return value

java/java-analysis-impl/src/com/intellij/codeInsight/daemon/impl/analysis/HighlightUtil.java

@@ -1479,6 +1479,19 @@ public class HighlightUtil extends HighlightUtilBase {
     return null;
   }
 
+  static void addLambdaReturnTypeFixes(HighlightInfo info, PsiLambdaExpression lambda, PsiExpression expression) {
+    PsiType type = LambdaUtil.getFunctionalInterfaceReturnType(lambda);
+    if (type != null) {
+      PsiType exprType = expression.getType();
+      if (exprType != null && TypeConversionUtil.areTypesConvertible(exprType, type)) {
+        QuickFixAction.registerQuickFixAction(info, QUICK_FIX_FACTORY.createAddTypeCastFix(type, expression));
+      }
+      QuickFixAction.registerQuickFixAction(info, QUICK_FIX_FACTORY.createWrapWithOptionalFix(type, expression));
+      QuickFixAction.registerQuickFixAction(info, QUICK_FIX_FACTORY.createWrapExpressionFix(type, expression));
+      QuickFixAction.registerQuickFixAction(info, QUICK_FIX_FACTORY.createWrapWithAdapterFix(type, expression));
+    }
+  }
+
   private enum SelectorKind { INT, ENUM, STRING }
 
   private static SelectorKind getSwitchSelectorKind(@NotNull PsiType type) {

java/java-analysis-impl/src/com/intellij/codeInsight/daemon/impl/analysis/HighlightVisitorImpl.java

@@ -376,6 +376,10 @@ public class HighlightVisitorImpl extends JavaElementVisitor implements Highligh
             .range(entry.getKey())
             .descriptionAndTooltip(entry.getValue()).create();
           QuickFixAction.registerQuickFixAction(info, AdjustFunctionContextFix.createFix(entry.getKey()));
+          if (entry.getKey() instanceof PsiExpression) {
+            PsiExpression expr = (PsiExpression)entry.getKey();
+            HighlightUtil.addLambdaReturnTypeFixes(info, expression, expr);
+          }
           myHolder.add(info);
         }
       }

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/addTypeCast/afterInLambda.java

@@ -0,0 +1,9 @@
+// "Cast to 'int'" "true"
+import java.util.*;
+import java.util.function.*;
+
+class Test {
+  void test() {
+    IntSupplier i = () -> (int) Math.PI;
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/addTypeCast/beforeInLambda.java

@@ -0,0 +1,9 @@
+// "Cast to 'int'" "true"
+import java.util.*;
+import java.util.function.*;
+
+class Test {
+  void test() {
+    IntSupplier i = () -> Math.<caret>PI;
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/wrapLongWithMathToIntExact/afterInLambda.java

@@ -0,0 +1,17 @@
+// "Wrap using 'Math.toIntExact()'" "true"
+import java.util.function.*;
+
+public class Test {
+
+    void m() {
+
+      LongToIntFunction fn = x -> {
+        if(x > 0) {
+          return Math.toIntExact(x * 2);
+        }
+        return 0;
+      };
+
+    }
+
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/wrapLongWithMathToIntExact/beforeInLambda.java

@@ -0,0 +1,17 @@
+// "Wrap using 'Math.toIntExact()'" "true"
+import java.util.function.*;
+
+public class Test {
+
+    void m() {
+
+      LongToIntFunction fn = x -> {
+        if(x > 0) {
+          return x<caret>*2;
+        }
+        return 0;
+      };
+
+    }
+
+}