diff --git a/package-lock.json b/package-lock.json
index 832bfd8..c8e4cd4 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -14,7 +14,8 @@
         "dotenv": "^16.4.5",
         "ffmetadata": "^1.7.0",
         "fpcalc": "^1.3.0",
-        "mime-types": "^2.1.35"
+        "mime-types": "^2.1.35",
+        "nock": "^13.5.4"
       },
       "bin": {
         "music-meta-finder": "cli.js"
@@ -3776,6 +3777,12 @@
       "integrity": "sha512-Bdboy+l7tA3OGW6FjyFHWkP5LuByj1Tk33Ljyq0axyzdk9//JSi2u3fP1QSmd1KNwq6VOKYGlAu87CisVir6Pw==",
       "dev": true
     },
+    "node_modules/json-stringify-safe": {
+      "version": "5.0.1",
+      "resolved": "https://registry.npmjs.org/json-stringify-safe/-/json-stringify-safe-5.0.1.tgz",
+      "integrity": "sha512-ZClg6AaYvamvYEE82d3Iyd3vSSIjQ+odgjaTzRuO3s7toCdFKczob2i0zCh7JE8kWn17yvAWhUVxvqGwUalsRA==",
+      "license": "ISC"
+    },
     "node_modules/json5": {
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/json5/-/json5-1.0.2.tgz",
@@ -4091,6 +4098,20 @@
         "@sinonjs/commons": "^3.0.0"
       }
     },
+    "node_modules/nock": {
+      "version": "13.5.4",
+      "resolved": "https://registry.npmjs.org/nock/-/nock-13.5.4.tgz",
+      "integrity": "sha512-yAyTfdeNJGGBFxWdzSKCBYxs5FxLbCg5X5Q4ets974hcQzG1+qCxvIyOo4j2Ry6MUlhWVMX4OoYDefAIIwupjw==",
+      "license": "MIT",
+      "dependencies": {
+        "debug": "^4.1.0",
+        "json-stringify-safe": "^5.0.1",
+        "propagate": "^2.0.0"
+      },
+      "engines": {
+        "node": ">= 10.13"
+      }
+    },
     "node_modules/node-int64": {
       "version": "0.4.0",
       "resolved": "https://registry.npmjs.org/node-int64/-/node-int64-0.4.0.tgz",
@@ -4419,6 +4440,15 @@
       "resolved": "https://registry.npmjs.org/process-nextick-args/-/process-nextick-args-2.0.1.tgz",
       "integrity": "sha512-3ouUOpQhtgrbOa17J7+uxOTpITYWaGP7/AhoR3+A+/1e9skrzelGi/dXzEYyvbxubEF6Wn2ypscTKiKJFFn1ag=="
     },
+    "node_modules/propagate": {
+      "version": "2.0.1",
+      "resolved": "https://registry.npmjs.org/propagate/-/propagate-2.0.1.tgz",
+      "integrity": "sha512-vGrhOavPSTz4QVNuBNdcNXePNdNMaO1xj9yBeH1ScQPjk/rhg9sSlCXPhMkFuaNNW/syTvYqsnbIJxMBfRbbag==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 8"
+      }
+    },
     "node_modules/proxy-from-env": {
       "version": "1.1.0",
       "resolved": "https://registry.npmjs.org/proxy-from-env/-/proxy-from-env-1.1.0.tgz",
diff --git a/package.json b/package.json
index 05ba7bf..c82f6cf 100644
--- a/package.json
+++ b/package.json
@@ -13,7 +13,8 @@
     "dotenv": "^16.4.5",
     "ffmetadata": "^1.7.0",
     "fpcalc": "^1.3.0",
-    "mime-types": "^2.1.35"
+    "mime-types": "^2.1.35",
+    "nock": "^13.5.4"
   },
   "devDependencies": {
     "@eslint/eslintrc": "^3.0.2",
diff --git a/test/utils/deleteDirectoryRecursively.test.js b/test/utils/deleteDirectoryRecursively.test.js
new file mode 100644
index 0000000..4dd991d
--- /dev/null
+++ b/test/utils/deleteDirectoryRecursively.test.js
@@ -0,0 +1,78 @@
+import { expect } from 'chai'
+import sinon from 'sinon';
+import fs from 'fs/promises';
+import path from "path";
+import deleteDirectoryRecursively from "../../src/utils/deleteDirectoryRecursively.js";
+
+describe('DeleteDirectoryRecursively', () => {
+  let readdirStub, unlinkStub, rmdirStub;
+
+  beforeEach(() => {
+    readdirStub = sinon.stub(fs, 'readdir');
+    unlinkStub = sinon.stub(fs, 'unlink');
+    rmdirStub = sinon.stub(fs, 'rmdir');
+  });
+
+  afterEach(() => {
+    readdirStub.restore();
+    unlinkStub.restore();
+    rmdirStub.restore();
+  });
+
+  it('should delete an empty directory', async () => {
+    const dirPath = 'testDir';
+
+    readdirStub.withArgs(dirPath).resolves([]);
+    rmdirStub.withArgs(dirPath).resolves();
+
+    await deleteDirectoryRecursively(dirPath);
+
+    expect(readdirStub.calledOnce).to.be.true;
+    expect(rmdirStub.calledOnceWith(dirPath)).to.be.true;
+  });
+
+  it('should delete a directory with files', async () => {
+    const dirPath = 'dir';
+    const filePath = path.join(dirPath, 'file.txt');
+
+    readdirStub.withArgs(dirPath).resolves([{ name: 'file.txt', isDirectory: () => false }]);
+    unlinkStub.withArgs(filePath).resolves();
+    rmdirStub.withArgs(dirPath).resolves();
+
+    await deleteDirectoryRecursively(dirPath);
+
+    expect(readdirStub.calledOnce).to.be.true;
+    expect(unlinkStub.calledOnceWith(filePath)).to.be.true;
+    expect(rmdirStub.calledOnceWith(dirPath)).to.be.true;
+  });
+
+  it('should delete a nested directory with files', async () => {
+    const dirPath = 'dir';
+    const nestedDirPath = path.join(dirPath, 'nestedDir');
+    const filePath = path.join(dirPath, 'file.txt');
+    const nestedFilePath = path.join(nestedDirPath, 'nestedFile.txt');
+
+    readdirStub.withArgs(dirPath).resolves([
+      { name: 'file.txt', isDirectory: () => false },
+      { name: 'nestedDir', isDirectory: () => true },
+    ]);
+
+    readdirStub.withArgs(nestedDirPath).resolves([
+      { name: 'nestedFile.txt', isDirectory: () => false },
+    ]);
+
+    unlinkStub.withArgs(filePath).resolves();
+    unlinkStub.withArgs(nestedFilePath).resolves();
+    rmdirStub.withArgs(dirPath).resolves();
+    rmdirStub.withArgs(nestedDirPath).resolves();
+
+    await deleteDirectoryRecursively(dirPath);
+
+    expect(readdirStub.calledTwice).to.be.true;
+    expect(unlinkStub.calledTwice).to.be.true;
+    expect(unlinkStub.calledWith(filePath)).to.be.true;
+    expect(unlinkStub.calledWith(nestedFilePath)).to.be.true;
+    expect(rmdirStub.calledWith(nestedDirPath)).to.be.true;
+    expect(rmdirStub.calledWith(dirPath)).to.be.true;
+  });
+})
diff --git a/test/utils/downloadImage.test.js b/test/utils/downloadImage.test.js
new file mode 100644
index 0000000..e69de29
diff --git a/test/utils/ensureDirectoryExists.test.js b/test/utils/ensureDirectoryExists.test.js
new file mode 100644
index 0000000..38fdb01
--- /dev/null
+++ b/test/utils/ensureDirectoryExists.test.js
@@ -0,0 +1,54 @@
+import { expect } from 'chai';
+import esmock from 'esmock';
+import sinon from 'sinon';
+import fs from 'fs';
+
+describe('ensureDirectoryExists', () => {
+  let ensureDirectoryExists;
+  let fsMock;
+  let sandbox;
+
+  beforeEach(async () => {
+    sandbox = sinon.createSandbox();
+    fsMock = {
+      existsSync: sandbox.stub(),
+      mkdirSync: sandbox.stub(),
+    };
+
+    // Dynamically import ensureDirectoryExists and replace fs with a mock
+    ensureDirectoryExists = await esmock(
+      '../../src/utils/ensureDirectoryExists.js',
+      {
+        'fs': fsMock,
+      }
+    );
+  });
+
+  afterEach(() => {
+    sandbox.restore();
+    esmock.purge(ensureDirectoryExists);
+  });
+
+  it('should not create a directory if it already exists', () => {
+    const dirPath = 'path/to/existing/dir';
+
+    fsMock.existsSync.returns(true);
+
+    ensureDirectoryExists(dirPath);
+
+    expect(fsMock.existsSync.calledOnceWith(dirPath)).to.be.true;
+    expect(fsMock.mkdirSync.notCalled).to.be.true;
+  });
+
+  it('should create a directory if it does not exist', () => {
+    const dirPath = 'path/to/new/dir';
+
+    fsMock.existsSync.returns(false);
+
+    ensureDirectoryExists(dirPath);
+
+    expect(fsMock.existsSync.calledOnceWith(dirPath)).to.be.true;
+    expect(fsMock.mkdirSync.calledOnceWith(dirPath, { recursive: true })).to.be.true;
+  });
+});
+
diff --git a/test/utils/fetchFiles.test.js b/test/utils/fetchFiles.test.js
new file mode 100644
index 0000000..4126957
--- /dev/null
+++ b/test/utils/fetchFiles.test.js
@@ -0,0 +1,89 @@
+import path from 'path';
+import { expect } from 'chai';
+import sinon from 'sinon';
+import esmock from 'esmock';
+
+function normalizeToForwardSlash(p) {
+  return p.split(path.sep).join('/');
+}
+
+describe('fetchFiles', () => {
+  let fetchFiles, fsStub;
+
+  beforeEach(async () => {
+    fsStub = {
+      promises: {
+        stat: sinon.stub(),
+        readdir: sinon.stub()
+      }
+    };
+
+    fetchFiles = await esmock('../../src/utils/fetchFiles.js', {
+      fs: fsStub
+    });
+  });
+
+  afterEach(() => {
+    esmock.purge(fetchFiles);
+    sinon.restore();
+  });
+
+  it('should return an array with a single file when given a file path', async () => {
+    const filePath = '/path/to/file.txt';
+
+    fsStub.promises.stat.resolves({ isFile: () => true, isDirectory: () => false });
+
+    const result = await fetchFiles(filePath);
+    expect(result).to.deep.equal([normalizeToForwardSlash(filePath)]);
+  });
+
+  it('should return an array of files when given a directory path', async () => {
+    const dirPath = '/path/to/directory';
+    const subdirPath = path.join(dirPath, 'subdir'); // Use path.join for consistency
+
+    fsStub.promises.stat.withArgs(dirPath).resolves({ isFile: () => false, isDirectory: () => true });
+    fsStub.promises.stat.withArgs(subdirPath).resolves({ isFile: () => false, isDirectory: () => true });
+    fsStub.promises.stat.resolves({ isFile: () => true, isDirectory: () => false }); // Default for files
+
+    fsStub.promises.readdir.withArgs(dirPath, { withFileTypes: true }).resolves([
+      { name: 'file1.txt', isFile: () => true, isDirectory: () => false },
+      { name: 'file2.txt', isFile: () => true, isDirectory: () => false },
+      { name: 'subdir', isFile: () => false, isDirectory: () => true }
+    ]);
+    fsStub.promises.readdir.withArgs(subdirPath, { withFileTypes: true }).resolves([
+      { name: 'file3.txt', isFile: () => true, isDirectory: () => false }
+    ]);
+
+    const result = await fetchFiles(dirPath);
+    console.log('Test Result:', result); // Add logging to debug the result
+    expect(result).to.deep.equal([
+      normalizeToForwardSlash(`${dirPath}/file1.txt`),
+      normalizeToForwardSlash(`${dirPath}/file2.txt`),
+      normalizeToForwardSlash(`${dirPath}/subdir/file3.txt`)
+    ]);
+  });
+
+  it('should throw an error if the path does not exist', async () => {
+    const invalidPath = '/invalid/path';
+
+    fsStub.promises.stat.rejects(new Error('ENOENT: no such file or directory'));
+
+    try {
+      await fetchFiles(invalidPath);
+    } catch (error) {
+      expect(error.message).to.equal('Failed to fetch files: ENOENT: no such file or directory');
+    }
+  });
+
+  it('should throw an error if the path is neither a file nor a directory', async () => {
+    const weirdPath = '/weird/path';
+
+    fsStub.promises.stat.resolves({ isFile: () => false, isDirectory: () => false });
+
+    try {
+      await fetchFiles(weirdPath);
+    } catch (error) {
+      expect(error.message).to.equal('Failed to fetch files: Input path is neither a file nor a directory: /weird/path');
+    }
+  });
+});
diff --git a/test/utils/renameAudioFileTitle.test.js b/test/utils/renameAudioFileTitle.test.js
new file mode 100644
index 0000000..dd10ea9
--- /dev/null
+++ b/test/utils/renameAudioFileTitle.test.js
@@ -0,0 +1,92 @@
+import path from 'path';
+import { expect } from 'chai';
+import sinon from 'sinon';
+import esmock from 'esmock';
+
+// Utility function to normalize paths to use forward slashes
+function normalizeToForwardSlash(p) {
+  return p.split(path.sep).join('/');
+}
+
+describe('renameFile', () => {
+  let renameFile, fsStub, generateUniqueFilenameStub;
+
+  beforeEach(async () => {
+    fsStub = {
+      rename: sinon.stub()
+    };
+
+    generateUniqueFilenameStub = sinon.stub();
+
+    renameFile = await esmock('../../src/utils/renameAudioFileTitle.js', {
+      'fs/promises': fsStub,
+      '../../src/utils/generateUniqueFilename.js': generateUniqueFilenameStub
+    });
+  });
+
+  afterEach(() => {
+    esmock.purge(renameFile);
+    sinon.restore();
+  });
+
+  it('should rename a file successfully with valid artist, title, and filePath', async () => {
+    const artist = 'Artist';
+    const title = 'Title';
+    const filePath = normalizeToForwardSlash('/path/to/file.mp3');
+    const newFilePath = normalizeToForwardSlash('/path/to/Artist - Title.mp3');
+
+    generateUniqueFilenameStub.resolves(newFilePath);
+    fsStub.rename.resolves();
+
+    const result = await renameFile(artist, title, filePath);
+
+    console.log('Arguments passed to generateUniqueFilename:', generateUniqueFilenameStub.args);
+    console.log('Arguments expected for generateUniqueFilename:', [normalizeToForwardSlash('/path/to'), normalizeToForwardSlash('Artist - Title.mp3')]);
+
+    expect(result).to.equal(normalizeToForwardSlash(newFilePath));
+    expect(generateUniqueFilenameStub.calledWith(normalizeToForwardSlash('/path/to'), 'Artist - Title.mp3')).to.be.true;
+    expect(fsStub.rename.calledWith(normalizeToForwardSlash(filePath), normalizeToForwardSlash(newFilePath))).to.be.true;
+  });
+
+  it('should throw an error if filePath, artist, or title are not provided', async () => {
+    try {
+      await renameFile('', 'Title', normalizeToForwardSlash('/path/to/file.mp3'));
+      throw new Error('Test failed - expected error not thrown');
+    } catch (error) {
+      expect(error.message).to.equal('File path, artist, and title must be provided when renaming file.');
+    }
+
+    try {
+      await renameFile('Artist', '', normalizeToForwardSlash('/path/to/file.mp3'));
+      throw new Error('Test failed - expected error not thrown');
+    } catch (error) {
+      expect(error.message).to.equal('File path, artist, and title must be provided when renaming file.');
+    }
+
+    try {
+      await renameFile('Artist', 'Title', '');
+      throw new Error('Test failed - expected error not thrown');
+    } catch (error) {
+      expect(error.message).to.equal('File path, artist, and title must be provided when renaming file.');
+    }
+  });
+
+  it('should throw an error if the file rename operation fails', async () => {
+    const artist = 'Artist';
+    const title = 'Title';
+    const filePath = normalizeToForwardSlash('/path/to/file.mp3');
+    const newFilePath = normalizeToForwardSlash('/path/to/Artist - Title.mp3');
+    const renameError = new Error('Rename failed');
+
+    generateUniqueFilenameStub.resolves(newFilePath);
+    fsStub.rename.rejects(renameError);
+
+    try {
+      await renameFile(artist, title, filePath);
+      throw new Error('Test failed - expected error not thrown');
+    } catch (error) {
+      expect(error).to.equal(renameError);
+    }
+  });
+});
+
diff --git a/test/utils/retryAxios.test.js b/test/utils/retryAxios.test.js
new file mode 100644
index 0000000..d313242
--- /dev/null
+++ b/test/utils/retryAxios.test.js
@@ -0,0 +1,75 @@
+import { expect } from 'chai';
+import nock from 'nock';
+import sinon from 'sinon';
+import esmock from 'esmock';
+
+describe('retryAxios', () => {
+  let axiosInstance, axios, axiosRetry;
+
+  beforeEach(async () => {
+    axios = {
+      create: sinon.stub().returnsThis(),
+      interceptors: {
+        response: {
+          use: sinon.stub()
+        }
+      }
+    };
+
+    axiosRetry = sinon.stub();
+
+    axiosInstance = await esmock('../../src/utils/retryAxios.js', {
+      'axios': axios,
+      'axios-retry': axiosRetry
+    });
+  });
+
+  it('should create an axios instance and configure retry policy', async () => {
+    expect(axios.create.calledOnce).to.be.true;
+    expect(axiosRetry.calledOnce).to.be.true;
+
+    const [instance, config] = axiosRetry.firstCall.args;
+    expect(instance).to.equal(axiosInstance);
+    expect(config.retries).to.equal(3);
+    expect(config.retryDelay(1)).to.equal(2000);
+    expect(config.retryDelay(2)).to.equal(4000);
+    expect(config.retryCondition({ response: { status: 429 }})).to.be.true;
+    expect(config.retryCondition({ response: { status: 500 }})).to.be.true;
+    expect(config.retryCondition({ response: { status: 400 }})).to.be.false;
+  });
+
+  it('should retry 3 times before failing for 500 status code', async () => {
+    nock('https://api.example.com')
+      .get('/resource')
+      .reply(500)
+      .persist();
+
+    let error;
+    try {
+      await axiosInstance.get('https://api.example.com/resource');
+    } catch (err) {
+      error = err;
+    }
+    expect(error).to.exist;
+
+    nock.cleanAll();
+  });
+
+  it('should not retry for 400 status code', async () => {
+    nock('https://api.example.com')
+      .get('/resource')
+      .reply(400);
+
+    let error;
+    try {
+      await axiosInstance.get('https://api.example.com/resource');
+    } catch (err) {
+      error = err;
+    }
+
+    expect(error).to.exist;
+
+    nock.cleanAll();
+  });
+});
+
diff --git a/test/utils/validateAudioFiles.test.js b/test/utils/validateAudioFiles.test.js
new file mode 100644
index 0000000..b6a81d7
--- /dev/null
+++ b/test/utils/validateAudioFiles.test.js
@@ -0,0 +1,78 @@
+import { expect } from 'chai';
+import sinon from 'sinon';
+import esmock from 'esmock';
+
+describe('validateAudioFile', () => {
+  let validateAudioFile, fsStub, mimeStub;
+
+  beforeEach(async () => {
+    fsStub = {
+      lstat: sinon.stub()
+    };
+
+    mimeStub = {
+      lookup: sinon.stub()
+    };
+
+    validateAudioFile = await esmock('../../src/utils/validateAudioFiles.js', {
+      'fs/promises': fsStub,
+      'mime-types': mimeStub
+    });
+  });
+
+  afterEach(() => {
+    esmock.purge(validateAudioFile);
+    sinon.restore();
+  });
+
+  it('should return null and log an error if the path is not a file', async () => {
+    const filePath = '/path/to/directory';
+    const consoleErrorStub = sinon.stub(console, 'error');
+
+    fsStub.lstat.resolves({ isFile: () => false });
+
+    const result = await validateAudioFile(filePath);
+    expect(result).to.be.null;
+    expect(consoleErrorStub.calledWith(`The path ${filePath} is not a file and is ignored.`)).to.be.true;
+
+    consoleErrorStub.restore();
+  });
+
+  it('should return null and log an error if the file is not a recognized audio file type', async () => {
+    const filePath = '/path/to/file.txt';
+    const consoleErrorStub = sinon.stub(console, 'error');
+
+    fsStub.lstat.resolves({ isFile: () => true });
+    mimeStub.lookup.returns('text/plain');
+
+    const result = await validateAudioFile(filePath);
+    expect(result).to.be.null;
+    expect(consoleErrorStub.calledWith(`File ${filePath} is not an audio file and is ignored.`)).to.be.true;
+
+    consoleErrorStub.restore();
+  });
+
+  it('should return the file path if the file is a recognized audio file type', async () => {
+    const filePath = '/path/to/file.mp3';
+
+    fsStub.lstat.resolves({ isFile: () => true });
+    mimeStub.lookup.returns('audio/mpeg');
+
+    const result = await validateAudioFile(filePath);
+    expect(result).to.equal(filePath);
+  });
+
+  it('should return null and log an error if an exception occurs during validation', async () => {
+    const filePath = '/path/to/file.mp3';
+    const error = new Error('Test Error');
+    const consoleErrorStub = sinon.stub(console, 'error');
+
+    fsStub.lstat.rejects(error);
+
+    const result = await validateAudioFile(filePath);
+    expect(result).to.be.null;
+    expect(consoleErrorStub.calledWith(`Error validating file ${filePath}: ${error}`)).to.be.true;
+
+    consoleErrorStub.restore();
+  });
+});