feat: add isIwaFile util

src/utils/index.ts

@@ -1 +1,2 @@
 export * from './get-message-proto';
+export * from './is-iwa-file';

src/utils/is-iwa-file.ts

@@ -0,0 +1,9 @@
+const IWA_FILE_DIRECTORY = 'Index/';
+const IWA_FILE_EXTENSION = '.iwa';
+
+/**
+ * Check if a file is an iwa file
+ */
+export const isIwaFile = (relativeFilePath: string): boolean =>
+  relativeFilePath.startsWith(IWA_FILE_DIRECTORY) &&
+  relativeFilePath.endsWith(IWA_FILE_EXTENSION);

tests/utils/is-iwa-file.spec.ts

@@ -0,0 +1,15 @@
+import { describe, expect, it } from 'vitest';
+import { isIwaFile } from '../../src';
+
+const testCases: [string, boolean][] = [
+  ['Index/foo.iwa', true],
+  ['Index/foo.jpg', false],
+  ['Metadata/foo.iwa', false],
+];
+
+describe('isIwaFile', () => {
+  testCases.forEach(([relativeFilePath, expected]) =>
+    it(`${relativeFilePath} -> ${expected}`, () =>
+      expect(isIwaFile(relativeFilePath)).toBe(expected)),
+  );
+});