Requests not handled after hot-code replacement

[danielwiehl]

Describe the bug

It turned out that after reloading the application due to hot code replacement, requests sent from a microfrontend to its activator may not be handled. This applies to both, intent- and topic-based requests.

When a micro application reloads during development, e.g., due to a code change, both its activators and regular microfrontends will reload at the same time. When the microfrontend initiates a request-reply communication with its activator, the handler may not yet be installed in the activator.

This problem does not exist for regular startups since the host app waits for all activators to complete initialization. However, in the process of hot code replacement, the host app is already operational and activators and regular microfrontends will boot simultaneously, causing the described bug.

There are several ways to address this problem:

• Add support for retained intents
• Wait to dispatch intents and messages to activator clients until they signal readiness
• ...

Environment

Please complete the following information:

• SCION Microfrontend Platform version: 1.0.0-beta.15

[danielwiehl]

We added support for retained intents in issue #142.

[k-genov]

Solved by #142.