Starting Ember 5.8.x with a blank `rootURL` throws an error because `baseURL` is `undefined` and so has no `replace` method

[BillyRayPreachersSon]

We're upgrading from Ember 3.28.x to 5.8.x, and have found an issue when starting our Ember server.

We've got no liveReloadBaseUrl config and no baseURL config, but we do have an empty string for our rootURL config.

The problem is that https://github.com/ember-cli/ember-cli-inject-live-reload/blob/master/lib/index.js#L51 checks as follows:

let baseURL = options.liveReloadBaseUrl || options.rootURL || options.baseURL;
...
let baseURLWithoutHost = baseURL.replace(/^https?:\/\/[^/]+/, '');

This is problematic because with an undefined value for both options.liveReloadBaseUrl and options.baseURL, baseURL resolves to undefined and so the .replace call is failing, even though we have a defined value of '' for options.rootURL.

I've added a temporary workaround (setting baseURL to '' in .ember-cli), and that appears to work... however, it would be nice to not have to add this workaround.

Would it be possible to use ?? instead of || for the falsey check?

[BillyRayPreachersSon]

Interesting... it looks like I have to set baseURL to '/' instead, otherwise the ember-cli-live-reload.js file gets a 404 when it tries to load.

Hopefully that doesn't cause issues when our app is deployed... I guess I will find out!

[Frank3K]

This pnpm patch works for us:

diff --git a/CHANGELOG.md b/CHANGELOG.md
deleted file mode 100644
index 6b246174165e3519b57dbb1fdd16a05731175763..0000000000000000000000000000000000000000
diff --git a/lib/index.js b/lib/index.js
index f28830e01df9778fcef712ccd546566bfc34a0cc..4779ee18a02417d8f9f0bfbe832762910cc709b4 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -48,7 +48,7 @@ module.exports = {
 
     let self = this;
     // maintaining `baseURL` for backwards compatibility. See: http://emberjs.com/blog/2016/04/28/baseURL.html
-    let baseURL = options.liveReloadBaseUrl || options.rootURL || options.baseURL;
+    let baseURL = options.liveReloadBaseUrl ?? options.rootURL ?? options.baseURL ?? '/';
     if (this.parent) {
       let checker = new VersionChecker(this.parent);
       let depedency = checker.for('ember-cli');
@@ -60,6 +60,8 @@ module.exports = {
     process.env.EMBER_CLI_INJECT_LIVE_RELOAD_BASEURL = baseURL;
 
     let baseURLWithoutHost = baseURL.replace(/^https?:\/\/[^/]+/, '');
+    if (!baseURLWithoutHost.startsWith('/')) { baseURLWithoutHost = '/' + baseURLWithoutHost; }
+    if (!baseURLWithoutHost.endsWith('/')) { baseURLWithoutHost = baseURLWithoutHost + '/'; }
     app.use(baseURLWithoutHost + 'ember-cli-live-reload.js', function(request, response) {
       response.contentType('text/javascript');
       response.send(self.dynamicScript(options));