semaphoreci/book-monorepo-cicd

Effectively build, test, and deploy code with monorepos.

book-monorepo-cicd's Issues

Change detection in monorepos with common libraries

Hi,

Thanks for writing and publishing the e-book. I enjoyed reading it.
One of the challenges I've faced when implementing CI/CD in monorepos is change detection in repos that have common source code packages. For example, imagine a repository that looks like this:

backend/
frontend/
common/lib1
common/lib2
common/lib3

Where backend and frontend are both dependent on packages that are under the common library and import their build artifacts using package managers' monorepo tooling such as yarn workspaces.

In this case I would like to build backend and frontend whenever there's a change in them or in any of the packages they depend on. If some packages in common also depend on other packages in common then it becomes a lot more complex.

Using file-path based change detection is cumbersome since you'd need to manually maintain a list of each deployable's deep dependencies in the repository.

Unfortunately, this is a very common use case in monorepos. I'd go as far as saying it's one of the biggest advantages monorepos give us (you even mention it in the book- easier dependency management).

Luckily, tools such as pnpm have CLI commands that make it easy to create a list of files that should trigger a change detection.

What would your recommendation be to make use of such tooling?
This is going into "feature request" territory, but is it possible to configure the change detection to take the file list from an environment variable? That way I can always run a job that populates the env variable with the more sophisticated tooling and only then would the change detection triggers be checked.

Thank you!

Please provide a direct link to download the PDF within README.md

To avoid a few turns in your favorite search engine or having to build the PDF manually.

Thanks!