IDEA-CR-20904 fixes after review (IDEA-123301 Show a warning if 'List<@Nullable X>' is passed to a place where 'List<@NotNull X'> is expected)

supported maps, inheritance, returns, functional expressions

java/java-tests/testData/inspection/nullableProblems/NotNullCollectionItemWithNullableSuperType.java

@@ -0,0 +1,8 @@
+import typeUse.*;
+import java.util.*;
+
+class MyList<T extends @NotNull Number> extends ArrayList<T> {}
+
+class SubList extends <warning descr="Nullable type arguments where non-null ones are expected">MyList</warning><@Nullable Integer> {
+  <warning descr="Nullable type arguments where non-null ones are expected">MyList</warning><@Nullable Integer> myList;
+}

java/java-tests/testData/inspection/nullableProblems/PassingNullableCollectionWhereNotNullIsExpected.java

@@ -1,21 +1,46 @@
 import typeUse.*;
 import java.util.*;
+import java.util.function.*;
 
 class JC {
 
-  public static void main(String[] args) {
-    List<@Nullable String> list = new ArrayList<>();
-    print(<warning descr="Assigning a collection of nullable elements into a collection of non-null elements">list</warning>);
+  void testList() {
+    List<@Nullable String> nullableList = new ArrayList<>();
+    print(<warning descr="Assigning a collection of nullable elements into a collection of non-null elements">nullableList</warning>);
 
-    List<@NotNull String> <warning descr="Assigning a collection of nullable elements into a collection of non-null elements">list2</warning> = list;
+    List<@NotNull String> <warning descr="Assigning a collection of nullable elements into a collection of non-null elements">list2</warning> = nullableList;
 
     List<@NotNull String> list3;
-    list2 <warning descr="Assigning a collection of nullable elements into a collection of non-null elements">=</warning> list;
-  }
+    list2 <warning descr="Assigning a collection of nullable elements into a collection of non-null elements">=</warning> nullableList;
 
+    List<? super @NotNull String> list4 = nullableList;
+    List<? extends @NotNull String> <warning descr="Assigning a collection of nullable elements into a collection of non-null elements">list5</warning> = nullableList;
+  }
+  
   private static void print(List<@NotNull String> list) {
     for (String s : list) {
       System.out.println(s.length());
     }
   }
+
+  List<@Nullable String> getNullableList() {return new ArrayList<>();}
+
+  List<@NotNull String> testReturnValue() {
+    List<@Nullable String> list = new ArrayList<>();
+
+    Supplier<List<@NotNull String>> supplier = () -> <warning descr="Assigning a collection of nullable elements into a collection of non-null elements">list</warning>;
+    Supplier<List<@NotNull String>> supplierRef = <warning descr="Assigning a collection of nullable elements into a collection of non-null elements">this::getNullableList</warning>;
+
+    Supplier<List<@NotNull String>> supplier3 = () -> { return <warning descr="Assigning a collection of nullable elements into a collection of non-null elements">list</warning>;};
+
+    return <warning descr="Assigning a collection of nullable elements into a collection of non-null elements">list</warning>;
+  }
+  
+}
+
+class Test<T extends @Nullable CharSequence> {
+  public void test() {
+    List<T> nullableList = new ArrayList<>();
+    List<? extends @NotNull CharSequence> <warning descr="Assigning a collection of nullable elements into a collection of non-null elements">list2</warning> = nullableList;
+  }
 }

java/java-tests/testData/inspection/nullableProblems/PassingNullableMapWhereNotNullIsExpected.java

@@ -0,0 +1,14 @@
+import typeUse.*;
+import java.util.*;
+
+class JC {
+
+  void testMap() {
+    Map<@NotNull String, @NotNull String> <warning descr="Assigning a collection of nullable elements into a collection of non-null elements">m1</warning> = new HashMap<@Nullable String, String>();
+    m1 <warning descr="Assigning a collection of nullable elements into a collection of non-null elements">=</warning> new HashMap<String, @Nullable String>();
+    m1 = new HashMap<String, String>();
+
+    Map<@NotNull String, ? extends @NotNull String> <warning descr="Assigning a collection of nullable elements into a collection of non-null elements">m2</warning> = new HashMap<@Nullable String, String>();
+  }
+
+}