test(tile-data): add tests for finding tiles

Author: ushkinaz

src/tile-data.test.ts

@@ -545,4 +545,49 @@ describe("findTile", () => {
       ty: 0,
     });
   });
+
+  test("matches entries whose id is a string array", () => {
+    const tile = findTile(
+      createTestTileset([
+        {
+          file: "aliases.webp",
+          nx: 2,
+          ny: 1,
+          tiles: [{ id: ["foo", "bar"], fg: 1 }],
+        },
+      ]),
+      "bar",
+    );
+
+    expect(tile?.fg).toMatchObject({
+      file: "aliases.webp",
+      tx: 1,
+      ty: 0,
+    });
+  });
+
+  test("resolves sprite references from fg and bg sprite objects", () => {
+    const tile = findTile(
+      createTestTileset([
+        {
+          file: "sprites.webp",
+          nx: 2,
+          ny: 2,
+          tiles: [{ id: "sprite-ref", fg: { sprite: 2 }, bg: { sprite: 3 } }],
+        },
+      ]),
+      "sprite-ref",
+    );
+
+    expect(tile?.fg).toMatchObject({
+      file: "sprites.webp",
+      tx: 0,
+      ty: 1,
+    });
+    expect(tile?.bg).toMatchObject({
+      file: "sprites.webp",
+      tx: 1,
+      ty: 1,
+    });
+  });
 });

src/tile-data.ts

@@ -688,11 +688,7 @@ function buildTileLookupIndex(tileData: IndexedTilesetData): TileLookupIndex {
   function firstSpriteRef(value: unknown): number | undefined {
     const maybeArrayHead = Array.isArray(value) ? value[0] : value;
     if (typeof maybeArrayHead === "number") return maybeArrayHead;
-    if (
-      typeof maybeArrayHead === "object" &&
-      maybeArrayHead !== null &&
-      typeof maybeArrayHead.sprite === "number"
-    ) {
+    if (isRecord(maybeArrayHead) && typeof maybeArrayHead.sprite === "number") {
       return maybeArrayHead.sprite;
     }
   }