diff --git a/jest.config.js b/jest.config.js
index e3b34b8..0524f52 100644
--- a/jest.config.js
+++ b/jest.config.js
@@ -1,4 +1,7 @@
 module.exports = {
+    setupFilesAfterEnv: [
+        './src/__test__/setup_jest.js'
+    ],
     moduleNameMapper: {
         '@/(.*)': '<rootDir>/src/$1'
     }
diff --git a/package-lock.json b/package-lock.json
index baed5be..4fed9de 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -12,7 +12,7 @@
       "dependencies": {
         "@babel/preset-typescript": "^7.16.5",
         "@jixun/qmc2-crypto": "^0.0.5-R4",
-        "@unlock-music/joox-crypto": "^0.0.1-R4",
+        "@unlock-music/joox-crypto": "^0.0.1-R5",
         "base64-js": "^1.5.1",
         "browser-id3-writer": "^4.4.0",
         "core-js": "^3.16.0",
@@ -3487,9 +3487,9 @@
       "dev": true
     },
     "node_modules/@unlock-music/joox-crypto": {
-      "version": "0.0.1-R4",
-      "resolved": "https://registry.npmjs.org/@unlock-music/joox-crypto/-/joox-crypto-0.0.1-R4.tgz",
-      "integrity": "sha512-5UScjXtH9J3mAy9sRBjNn5kkEuT7dHvH3YQYKRyOfF3EKxLkWsJP0Fuw/tZtylLPL5beI3qDBzyHf5mVrpdH4A==",
+      "version": "0.0.1-R5",
+      "resolved": "https://registry.npmjs.org/@unlock-music/joox-crypto/-/joox-crypto-0.0.1-R5.tgz",
+      "integrity": "sha512-+FhGT4bjzfb1Q7dAwHps/XqbqXrRA6Qg7pkDPzyXfeRmQocAySQ/dekojxkaFBf7ZX5ToIAopwxkKZ5NFt5bFw==",
       "dependencies": {
         "crypto-js": "^4.1.1"
       },
@@ -23635,9 +23635,9 @@
       "dev": true
     },
     "@unlock-music/joox-crypto": {
-      "version": "0.0.1-R4",
-      "resolved": "https://registry.npmjs.org/@unlock-music/joox-crypto/-/joox-crypto-0.0.1-R4.tgz",
-      "integrity": "sha512-5UScjXtH9J3mAy9sRBjNn5kkEuT7dHvH3YQYKRyOfF3EKxLkWsJP0Fuw/tZtylLPL5beI3qDBzyHf5mVrpdH4A==",
+      "version": "0.0.1-R5",
+      "resolved": "https://registry.npmjs.org/@unlock-music/joox-crypto/-/joox-crypto-0.0.1-R5.tgz",
+      "integrity": "sha512-+FhGT4bjzfb1Q7dAwHps/XqbqXrRA6Qg7pkDPzyXfeRmQocAySQ/dekojxkaFBf7ZX5ToIAopwxkKZ5NFt5bFw==",
       "requires": {
         "crypto-js": "^4.1.1"
       }
diff --git a/package.json b/package.json
index f6295bb..12644ef 100644
--- a/package.json
+++ b/package.json
@@ -22,7 +22,7 @@
   "dependencies": {
     "@babel/preset-typescript": "^7.16.5",
     "@jixun/qmc2-crypto": "^0.0.5-R4",
-    "@unlock-music/joox-crypto": "^0.0.1-R4",
+    "@unlock-music/joox-crypto": "^0.0.1-R5",
     "base64-js": "^1.5.1",
     "browser-id3-writer": "^4.4.0",
     "core-js": "^3.16.0",
diff --git a/src/__test__/setup_jest.js b/src/__test__/setup_jest.js
new file mode 100644
index 0000000..c7b47bf
--- /dev/null
+++ b/src/__test__/setup_jest.js
@@ -0,0 +1,2 @@
+// Polyfill for node.
+global.Blob = global.Blob || require("node:buffer").Blob;
diff --git a/src/decrypt/__test__/fixture/joox_1.bin b/src/decrypt/__test__/fixture/joox_1.bin
new file mode 100644
index 0000000..5ffe376
Binary files /dev/null and b/src/decrypt/__test__/fixture/joox_1.bin differ
diff --git a/src/decrypt/__test__/joox.test.ts b/src/decrypt/__test__/joox.test.ts
new file mode 100644
index 0000000..dd0af1d
--- /dev/null
+++ b/src/decrypt/__test__/joox.test.ts
@@ -0,0 +1,52 @@
+import fs from 'fs';
+import { storage } from '@/utils/storage';
+
+import { Decrypt as decryptJoox } from '../joox';
+import { extractQQMusicMeta as extractQQMusicMetaOrig } from '@/utils/qm_meta';
+
+jest.mock('@/utils/storage');
+jest.mock('@/utils/qm_meta');
+
+const loadJooxUUID = storage.loadJooxUUID as jest.MockedFunction<typeof storage.loadJooxUUID>;
+const extractQQMusicMeta = extractQQMusicMetaOrig as jest.MockedFunction<typeof extractQQMusicMetaOrig>;
+
+const TEST_UUID_ZEROS = ''.padStart(32, '0');
+const encryptedFile1 = fs.readFileSync(__dirname + '/fixture/joox_1.bin');
+
+describe('decrypt/joox', () => {
+  it('should be able to decrypt sample file (v4)', async () => {
+    loadJooxUUID.mockResolvedValue(TEST_UUID_ZEROS);
+    extractQQMusicMeta.mockImplementationOnce(async (blob: Blob) => {
+      return {
+        title: 'unused',
+        album: 'unused',
+        blob: blob,
+        artist: 'unused',
+        imgUrl: 'https://github.com/unlock-music',
+      };
+    });
+
+    const result = await decryptJoox(new Blob([encryptedFile1]), 'test.bin', 'bin');
+    const resultBuf = await result.blob.arrayBuffer();
+    expect(resultBuf).toEqual(Buffer.from('Hello World', 'utf-8').buffer);
+  });
+
+  it('should reject E!99 files', async () => {
+    loadJooxUUID.mockResolvedValue(TEST_UUID_ZEROS);
+
+    const input = new Blob([Buffer.from('E!99....')]);
+    await expect(decryptJoox(input, 'test.bin', 'bin')).rejects.toThrow('不支持的 joox 加密格式');
+  });
+
+  it('should reject empty uuid', async () => {
+    loadJooxUUID.mockResolvedValue('');
+    const input = new Blob([encryptedFile1]);
+    await expect(decryptJoox(input, 'test.bin', 'bin')).rejects.toThrow('UUID');
+  });
+
+  it('should reject invalid uuid', async () => {
+    loadJooxUUID.mockResolvedValue('hello!');
+    const input = new Blob([encryptedFile1]);
+    await expect(decryptJoox(input, 'test.bin', 'bin')).rejects.toThrow('UUID');
+  });
+});
diff --git a/src/utils/__mocks__/qm_meta.ts b/src/utils/__mocks__/qm_meta.ts
new file mode 100644
index 0000000..99c3cec
--- /dev/null
+++ b/src/utils/__mocks__/qm_meta.ts
@@ -0,0 +1 @@
+export const extractQQMusicMeta = jest.fn();
diff --git a/src/utils/__mocks__/storage.ts b/src/utils/__mocks__/storage.ts
new file mode 100644
index 0000000..af9fd67
--- /dev/null
+++ b/src/utils/__mocks__/storage.ts
@@ -0,0 +1,4 @@
+export const storage = {
+  loadJooxUUID: jest.fn(),
+  saveJooxUUID: jest.fn(),
+};