Added WebStorage tests

.github/workflows/ci.yaml

@@ -41,3 +41,6 @@ jobs:
 
             - name: Unit tests (IndexedDB)
               run: npx zenfs-test tests/setup-idb.ts
+
+            - name: Unit tests (WebStorage)
+              run: npx zenfs-test tests/setup-storage.ts

package.json

@@ -43,7 +43,6 @@
 	"devDependencies": {
 		"@eslint/js": "^9.12.0",
 		"eslint": "^9.12.0",
-		"fake-indexeddb": "^6.0.0",
 		"globals": "^15.10.0",
 		"prettier": "^3.2.5",
 		"typedoc": "^0.26.10",
@@ -53,6 +52,9 @@
 	"peerDependencies": {
 		"@zenfs/core": "^1.2.0"
 	},
+	"optionalDependencies": {
+		"fake-indexeddb": "^6.0.0"
+	},
 	"keywords": [
 		"filesystem",
 		"node",

src/Storage.ts

@@ -76,6 +76,9 @@ const _WebStorage = {
 		},
 	},
 
+	/**
+	 * @todo Consider replacing `instanceof` with a duck-typing check?
+	 */
 	isAvailable(storage: Storage = globalThis.localStorage): boolean {
 		return storage instanceof globalThis.Storage;
 	},

tests/setup-storage.ts

@@ -0,0 +1,39 @@
+import { configureSingle } from '@zenfs/core';
+import { WebStorage } from '../src/Storage.js';
+import { copy, data } from '@zenfs/core/tests/setup/common.js';
+
+const storage = {
+	_: new Map<string, string>(),
+
+	get length(): number {
+		return this._.size;
+	},
+
+	clear(): void {
+		this._.clear();
+	},
+
+	getItem(key: string): string | null {
+		return this._.get(key) ?? null;
+	},
+
+	key(index: number): string | null {
+		return Array.from(this._.keys())[index];
+	},
+
+	removeItem(key: string): void {
+		this._.delete(key);
+	},
+
+	setItem(key: string, value: string): void {
+		this._.set(key, value);
+	},
+};
+
+// @ts-expect-error 2322
+globalThis.Storage = Object; // Bypass `instanceof` check in `WebStorage` is available
+globalThis.localStorage = storage;
+
+await configureSingle({ backend: WebStorage, storage });
+
+copy(data);