implement custom config dir arg

closes #1956

cli.md

@@ -37,6 +37,7 @@ LosslessCut --settings-json '{captureFormat:"jpeg", "keyframeCut":true}'
 - `--disable-networking` Turn off all network requests.
 - `--http-api` Start the [HTTP server with an API](./api.md) to control LosslessCut, optionally specifying a port (default `8080`).
 - `--keyboard-action` Run a keyboard action (see below.)
+- `--custom-config-dir` Path to a directory where the `config.json` file will be stored and loaded from.
 
 ## Controlling a running instance (experimental)
 

src/main/configStore.ts

@@ -145,17 +145,18 @@ const defaults: Config = {
   invertTimelineScroll: undefined,
 };
 
+// look for a config.json file next to the executable
 // For portable app: https://github.com/mifi/lossless-cut/issues/645
-async function getCustomStoragePath() {
+async function lookForCustomStoragePath() {
   try {
-    if (!isWindows || process.windowsStore) return undefined;
-
     // https://github.com/mifi/lossless-cut/issues/645#issuecomment-1001363314
     // https://stackoverflow.com/questions/46307797/how-to-get-the-original-path-of-a-portable-electron-app
     // https://github.com/electron-userland/electron-builder/blob/master/docs/configuration/nsis.md
+    if (!isWindows || process.windowsStore) return undefined;
     const customStorageDir = process.env['PORTABLE_EXECUTABLE_DIR'] || dirname(app.getPath('exe'));
     const customConfigPath = join(customStorageDir, 'config.json');
     if (await pathExists(customConfigPath)) return customStorageDir;
+
     return undefined;
   } catch (err) {
     logger.error('Failed to get custom storage path', err);
@@ -196,8 +197,8 @@ async function tryCreateStore({ customStoragePath }: { customStoragePath: string
   throw new Error('Timed out while creating config store');
 }
 
-export async function init() {
-  const customStoragePath = await getCustomStoragePath();
+export async function init({ customConfigDir }: { customConfigDir: string | undefined }) {
+  const customStoragePath = customConfigDir ?? await lookForCustomStoragePath();
   if (customStoragePath) logger.info('customStoragePath', customStoragePath);
 
   await tryCreateStore({ customStoragePath });

src/main/index.ts

@@ -231,7 +231,10 @@ function parseCliArgs(rawArgv = process.argv) {
   // dev: First 2 args are electron and the index.js
   const argsWithoutAppName = rawArgv.length > ignoreFirstArgs ? rawArgv.slice(ignoreFirstArgs) : [];
 
-  return yargsParser(argsWithoutAppName, { boolean: ['allow-multiple-instances', 'disable-networking'], string: ['settings-json'] });
+  return yargsParser(argsWithoutAppName, {
+    boolean: ['allow-multiple-instances', 'disable-networking'],
+    string: ['settings-json', 'custom-config-dir'],
+  });
 }
 
 const argv = parseCliArgs();
@@ -330,7 +333,7 @@ const readyPromise = app.whenReady();
 (async () => {
   try {
     logger.info('Initializing config store');
-    await configStore.init();
+    await configStore.init({ customConfigDir: argv['customConfigDir'] });
 
     const allowMultipleInstances = configStore.get('allowMultipleInstances');