test: reformat and expand test coverage

tests/core/game.test.ts

@@ -63,7 +63,10 @@ describe("createGameContext", () => {
     registry.register(
       "test <value>",
       async function (this: CommandRunnerContext<IGameContext>, _ctx, value) {
-        return this.prompt(createPromptDef("prompt <answer>"), () => "ok");
+        return this.prompt(
+          createPromptDef("prompt <answer>"),
+          (answer) => answer,
+        );
       },
     );
 

tests/samples/slay-the-spire-like/grid-inventory.test.ts

@@ -23,7 +23,7 @@ function createTestItem(
   id: string,
   shapeStr: string,
   transform = IDENTITY_TRANSFORM,
-): InventoryItem {
+): InventoryItem<Record<string, never>> {
   const shape = parseShapeString(shapeStr);
   return {
     id,