Ruby: Add test case for view without ERB template

ruby/ql/test/library-tests/dataflow/erb/main.rb

@@ -16,4 +16,10 @@ class App
         view = View3.new(x)
         render(view)
     end
+
+    def run4
+        x = source(5)
+        view = View4.new(x)
+        render(view)
+    end
 end

ruby/ql/test/library-tests/dataflow/erb/view4.rb

@@ -0,0 +1,15 @@
+# This component has no corresponding template file, because it defines a `call` method instead.
+
+class View4 < ViewComponent::Base
+    def initialize(x)
+        @x = x
+    end
+
+    def get
+        @x
+    end
+
+    def call
+        "hi"
+    end
+end