Add tests, including issue failing on main branch

spec/type_checker/levels/strict_spec.rb

@@ -376,6 +376,53 @@ def bar(baz)
       expect(checker.problems.first.message).to include('Not enough arguments')
     end
 
+    it 'reports solo missing kwarg' do
+      checker = type_checker(%(
+        class Foo
+          def bar(baz:)
+          end
+        end
+        Foo.new.bar
+      ))
+      expect(checker.problems).to be_one
+      expect(checker.problems.first.message).to include('Missing keyword arguments')
+    end
+
+    it 'reports not enough kwargs' do
+      checker = type_checker(%(
+        class Foo
+          def bar(foo:, baz:)
+          end
+        end
+        Foo.new.bar(foo: 100)
+      ))
+      expect(checker.problems).to be_one
+      expect(checker.problems.first.message).to include('Missing keyword argument')
+      expect(checker.problems.first.message).to include('baz')
+    end
+
+    it 'accepts passed kwargs' do
+      checker = type_checker(%(
+        class Foo
+          def bar(baz:)
+          end
+        end
+        Foo.new.bar(baz: 123)
+      ))
+      expect(checker.problems).to be_empty
+    end
+
+    it 'accepts multiple passed kwargs' do
+      checker = type_checker(%(
+        class Foo
+          def bar(baz:, bing:)
+          end
+        end
+        Foo.new.bar(baz: 123, bing: 456)
+      ))
+      expect(checker.problems).to be_empty
+    end
+
     it 'requires strict return tags' do
       checker = type_checker(%(
         class Foo