fix: assert index as typeof solution in shape-of-types (#184)

Author: JoshuaKGoldberg

projects/classes/the-shape-of-types/src/index.test.ts

@@ -5,7 +5,10 @@ import * as solution from "./solution";
 
 const { Demon, Horror, Sorcerer } = process.env.TEST_SOLUTIONS
 	? solution
-	: index;
+	: // In theory, it would be nice to not have to apply this cast
+	  // In practice, TypeScript's structural typing does not play well with # privates
+	  // See https://github.com/LearningTypeScript/projects/issues/183
+	  (index as unknown as typeof solution);
 
 class MockHorror extends Horror {
 	name = "";