I’m writing this story partly for my future self — so I’ll have this recipe at my fingertips if I ever need to do it again — and partly for others, to hopefully spare some poor souls some of the pain that I just went through.

Prologue

I inherited a task to implement a file upload feature in our Angular 8 app.

What made this task a bit different than a typical file upload was that we weren’t uploading directly to the file storage server, we were uploading to our intermediate Node server (owned by the Frontend team, my team) which…

I recently had a requirement to make sure a PrimeNG Dropdown panel inside a modal with scrolling content was not constrained within the modal, but rather could be seen and interacted with without having to scroll.

Here’s what I’m talking about…

The Scenario

This is the default, and what we don’t want (or, rather, what we shall not deliver):

Writing unit tests can be fun but also tricky, especially if you’re testing code that may not have been written with unit testing in mind.

One scenario that I keep encountering in various ways — my own unit testing tasks, teammates at work asking “How do I test this?”, this StackOverflow question — is how to unit test a module or function that has business logic contained within a callback function being invoked by a nested entity that needs to be mocked for the test.

The Scenario

Here’s an example of app code I’m talking about (Node app code, in this case)…