[bug] Breaking change for dependent targets in v1.30.0

[dudicoco]

Describe the bug

The behavior of moon ci triggering of affected targets was changed in v1.30.0.

There are two issues here:

1. While this is partially a desired change in my view as it resolves https://github.com/moonrepo/moon/issues/1624, it is nonetheless a breaking change and should have been introduced behind a flag or mentioned in the release notes.
2. It introduced a side effect of affected dependencies of a target triggering their own dependents, which is undesired in my view.

Steps to reproduce

Full reproduction is available in this branch

1. Use moon v1.29.4
2. Make a change to apps/backend/app-01/package.json
3. Commit
4. Run moon ci --base HEAD~1:

   
   $ moon --version        
   moon 1.29.4

$ moon ci --base HEAD~1 ▪▪▪▪ Gathering touched files apps/backend/app-01/package.json ▪▪▪▪ Gathering potential targets app-01:install app-02:install ▪▪▪▪ Generating action graph Target count: 2 Action count: 6 ▪▪▪▪ Running tasks installing ▪▪▪▪ root:install ▪▪▪▪ root:install (11ms) app-01:install | test ▪▪▪▪ app-01:install (cached, 5aba2e13)

SUMMARY

pass SyncWorkspace (46ms) skip SetupToolchain(system) (skipped, 5ms) pass SyncProject(system, root) (5ms) pass SyncProject(system, app-01) (5ms) pass RunTask(root:install) (15ms) pass RunTask(app-01:install) (cached, 40ms, 5aba2e13)

STATS

Actions: 5 completed (1 cached), 1 skipped Time: 113ms

5. Switch to moon v1.30.0
6. Run `moon ci --base HEAD~1`:
```sh
$ moon ci --base HEAD~1
▪▪▪▪ Gathering touched files
  apps/backend/app-01/package.json
▪▪▪▪ Gathering potential targets
  app-01:install
  app-02:install
▪▪▪▪ Generating action graph
Target count: 2
Action count: 8
▪▪▪▪ Running tasks
▪▪▪▪ root:install
  root:install | installing
▪▪▪▪ root:install (9ms)
app-01:install | test
▪▪▪▪ app-01:install (cached, 5aba2e13)
app-02:install | test
▪▪▪▪ app-02:install (cached, 009f8d7a)

 SUMMARY 

pass SyncWorkspace (33ms)
skip SetupToolchain(system) (skipped)
pass SyncProject(system, root) 
pass SyncProject(system, app-02) 
pass SyncProject(system, app-01) 
pass RunTask(root:install) (11ms)
pass RunTask(app-01:install) (cached, 30ms, 5aba2e13)
pass RunTask(app-02:install) (cached, 39ms, 009f8d7a)

 STATS 

Actions: 7 completed (2 cached), 1 skipped
   Time: 86ms

As you can see in the second run with moon v1.30.0, the root:install task which was triggered because it's a dependency of the app-01:install task, triggered its own dependents - app-02:install.

Expected behavior

I would want a way to control if a dependency triggered by upstream tasks wii trigger its own dependents.

[milesj]

@dudicoco We don't run dependents for the dependencies of a task. The logic is here: https://github.com/moonrepo/moon/blob/master/crates/action-graph/src/action_graph_builder.rs#L392

We create a new RunRequirements struct with default values, which sets the dependents field to false.

I think something else may be going on, can you paste the --log trace output? Can you also paste the output of moon task-graph app-01:install --dot?