diff --git a/app/lib/encoding/encodingMain.js b/app/lib/encoding/encodingMain.js
index 394c5c8..5512139 100644
--- a/app/lib/encoding/encodingMain.js
+++ b/app/lib/encoding/encodingMain.js
@@ -79,7 +79,7 @@ exports.ENCODINGS = [
 exports.init = (mainMenu, storageDir, electronMock) => {
     electron = electronMock ?? require("electron")
     _mainMenu = mainMenu
-    _storageDir = storageDir ?? storage.getDefaultDir()
+    _storageDir = storageDir ?? storage.dataDir
 
     electron.ipcMain.on(ipc.messages.changeEncoding, (_, filePath, encoding) =>
         changeEncoding(filePath, encoding)
diff --git a/app/lib/main/cli.js b/app/lib/main/cli.js
new file mode 100644
index 0000000..f307acc
--- /dev/null
+++ b/app/lib/main/cli.js
@@ -0,0 +1,58 @@
+const path = require("path")
+
+let electron
+
+const DEFAULT_FILE = path.join(__dirname, "..", "..", "..", "README.md")
+
+function extractInternalTarget(args) {
+    return args.find(arg => arg.startsWith("#"))
+}
+
+function extractFilePath(args, storageDirArgIndex) {
+    return (
+        args.find(
+            arg =>
+                arg !== process.execPath &&
+                arg !== "." &&
+                arg !== electron.app.getAppPath() &&
+                arg !== "data:," &&
+                !arg.startsWith("-") &&
+                !arg.startsWith("#") &&
+                args.indexOf(arg) !== storageDirArgIndex
+        ) ?? DEFAULT_FILE
+    )
+}
+
+function parseTestArgs(args) {
+    const testArgIndex = args.indexOf("--test")
+    const isTest = testArgIndex >= 0
+
+    let storageDirArgIndex = -1
+    if (isTest && testArgIndex < args.length - 1) {
+        storageDirArgIndex = testArgIndex + 1
+    }
+
+    return {
+        isTest: isTest,
+        storageDir:
+            storageDirArgIndex >= 0
+                ? args[storageDirArgIndex]
+                : path.join(electron.app.getPath("userData"), "storage"),
+        storageDirArgIndex: storageDirArgIndex,
+    }
+}
+
+exports.init = electronMock => (electron = electronMock ?? require("electron"))
+
+exports.parse = args => {
+    console.debug(args)
+    const { isTest, storageDir, storageDirArgIndex } = parseTestArgs(args)
+    const parsedArgs = {
+        filePath: extractFilePath(args, storageDirArgIndex),
+        internalTarget: extractInternalTarget(args),
+        isTest: isTest,
+        storageDir: storageDir,
+    }
+    console.debug(parsedArgs)
+    return parsedArgs
+}
diff --git a/app/lib/main/storage.js b/app/lib/main/storage.js
index c138ea4..10534f7 100644
--- a/app/lib/main/storage.js
+++ b/app/lib/main/storage.js
@@ -6,6 +6,8 @@ let electron
 const APPLICATION_SETTINGS_FILE = "app-settings.json"
 const DOCUMENT_SETTINGS_FILE = "doc-settings.json"
 
+let _dataDir
+
 let _applicationSettings
 let _documentSettings = {}
 
@@ -28,7 +30,7 @@ class StorageBase {
     }
 
     static _initStorageDir(storageDir) {
-        fs.mkdirSync(storageDir ?? getDefaultDir(), { recursive: true })
+        fs.mkdirSync(storageDir ?? _dataDir, { recursive: true })
     }
 
     static _initData(storagePath) {
@@ -127,16 +129,14 @@ class DocumentSettings extends StorageBase {
     }
 }
 
-function getDefaultDir() {
-    // electron.app.getPath does not work in tests
-    return path.join(electron.app.getPath("userData"), "storage")
-}
-
 exports.APPLICATION_SETTINGS_FILE = APPLICATION_SETTINGS_FILE
 
 exports.DOCUMENT_SETTINGS_FILE = DOCUMENT_SETTINGS_FILE
 
-exports.init = electronMock => (electron = electronMock ?? require("electron"))
+exports.init = (dataDir, electronMock) => {
+    electron = electronMock ?? require("electron")
+    exports.dataDir = _dataDir = dataDir
+}
 
 exports.loadApplicationSettings = (storageDir, storageFile) =>
     _applicationSettings ??
@@ -145,5 +145,3 @@ exports.loadApplicationSettings = (storageDir, storageFile) =>
 exports.loadDocumentSettings = (storageDir, storageFile, documentPath) =>
     _documentSettings[documentPath] ??
     (_documentSettings[documentPath] = new DocumentSettings(storageDir, storageFile, documentPath))
-
-exports.getDefaultDir = getDefaultDir
diff --git a/app/main.js b/app/main.js
index 5a7ec01..005daec 100644
--- a/app/main.js
+++ b/app/main.js
@@ -8,6 +8,7 @@ const childProcess = require("child_process")
 const electron = require("electron")
 const remote = require("@electron/remote/main")
 
+const cli = require("./lib/main/cli")
 const common = require("./lib/common")
 const contentBlocking = require("./lib/contentBlocking/contentBlockingMain")
 const encodingLib = require("./lib/encoding/encodingMain")
@@ -21,6 +22,7 @@ const UPDATE_INTERVAL = 1000 // ms
 const UPDATE_FILE_TIME_NAV_ID = "update-file-time"
 const ZOOM_STEP = 0.1
 
+let _cliArgs
 let _isTest = false
 
 let _mainWindow
@@ -82,22 +84,10 @@ function openFile(filePath, internalTarget, encoding) {
     }
 }
 
-function extractInternalTarget(args) {
-    return args.find(arg => arg.startsWith("#"))
-}
-
-function determineCurrentFilePath(args) {
+function determineCurrentFilePath() {
     return navigation.hasCurrentLocation()
         ? navigation.getCurrentLocation().filePath
-        : args.find(
-              arg =>
-                  arg !== process.execPath &&
-                  arg !== "." &&
-                  arg !== electron.app.getAppPath() &&
-                  arg !== "data:," &&
-                  !arg.startsWith("-") &&
-                  !arg.includes("spectron-menu-addon-v2")
-          ) ?? DEFAULT_FILE
+        : _cliArgs.filePath
 }
 
 function createChildWindow(filePath, internalTarget) {
@@ -145,9 +135,9 @@ function resetZoom() {
 
 function createWindow() {
     const windowPosition = storage.loadDocumentSettings(
-        storage.getDefaultDir(),
+        storage.dataDir,
         storage.DOCUMENT_SETTINGS_FILE,
-        determineCurrentFilePath(process.argv)
+        determineCurrentFilePath()
     ).windowPosition
 
     const mainWindow = new electron.BrowserWindow({
@@ -164,9 +154,9 @@ function createWindow() {
     })
     mainWindow.on("close", () => {
         const documentSettings = storage.loadDocumentSettings(
-            storage.getDefaultDir(),
+            storage.dataDir,
             storage.DOCUMENT_SETTINGS_FILE,
-            determineCurrentFilePath(process.argv)
+            determineCurrentFilePath()
         )
         documentSettings.windowPosition = mainWindow.getBounds()
     })
@@ -369,11 +359,12 @@ function createWindow() {
 }
 
 electron.app.on("ready", () => {
-    _isTest = process.argv.includes("--test")
+    cli.init()
+    _cliArgs = cli.parse(process.argv)
 
-    storage.init()
+    storage.init(_cliArgs.storageDir)
     _applicationSettings = storage.loadApplicationSettings(
-        storage.getDefaultDir(),
+        storage.dataDir,
         storage.APPLICATION_SETTINGS_FILE
     )
 
@@ -403,11 +394,8 @@ electron.app.on("activate", () => {
 })
 
 electron.ipcMain.on(ipc.messages.finishLoad, () => {
-    const args = process.argv
-    console.debug(args)
-
-    const filePath = determineCurrentFilePath(args)
-    if (openFile(filePath, extractInternalTarget(args), encodingLib.load(filePath))) {
+    const filePath = _cliArgs.filePath
+    if (openFile(filePath, _cliArgs.internalTarget, encodingLib.load(filePath))) {
         setZoom(_applicationSettings.zoom)
     }
 })
diff --git a/test/integrationSpec.js b/test/integrationSpec.js
index 4897532..f9d1932 100644
--- a/test/integrationSpec.js
+++ b/test/integrationSpec.js
@@ -98,7 +98,7 @@ describe("Integration tests with single app instance", () => {
 
             beforeEach(() => {
                 mocking.resetElectron()
-                storage.init(mocking.electron)
+                storage.init(mocking.dataDir, mocking.electron)
                 applicationSettings = storage.loadApplicationSettings(
                     mocking.dataDir,
                     storage.APPLICATION_SETTINGS_FILE