lambda: infer from return type; cyclic inference stop

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/inference/FunctionalInterfaceShouldHaveExactlyOneMethod.java

@@ -0,0 +1,48 @@
+public class NotAFIT {
+  static class First {
+    static interface A<T> {
+      void foo1();
+      void foo2();
+    }
+    static <T> void foo(A<T> a) {
+    }
+
+    void bar() {
+        foo(<error descr="Multiple non-overriding abstract methods found">() ->{}</error>);
+    }
+  }
+
+  static class WithInheritance {
+    static interface A<T> {
+      void foo1();
+    }
+
+    static interface B<M> extends A<M> {
+      void foo2();
+    }
+
+    static <T> void foo(B<T> a) {
+    }
+
+    void bar() {
+      foo(<error descr="Multiple non-overriding abstract methods found">()->{}</error>);
+    }
+  }
+
+  static class WithInheritanceOverrideSameMethod {
+    static interface A<T> {
+      void foo1();
+    }
+
+    static interface B<M> extends A<M> {
+      void foo1();
+    }
+
+    static <T> void foo(B<T> a) {
+    }
+
+    void bar() {
+      foo(()->{});
+    }
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/inference/SimpleCyclicInference.java

@@ -0,0 +1,20 @@
+class NoLambda {
+    interface I<T> {
+        void f(T t);
+    }
+
+    <Z> void bar(I<Z> iz) {
+    }
+
+    void bazz() {
+        bar(null);
+        bar(<error descr="Cyclic inference">(z)-> {System.out.println();}</error>);
+    }
+  
+    static <T> T id(T i2) {return i2;}
+
+    {
+       id(<error descr="Cyclic inference">() -> {System.out.println("hi");}</error>);
+       NoLambda.<Runnable>id(() -> {System.out.println("hi");});
+    }
+}