chore(ci): pick better which packages should compile and test

[david-luna]

ref: #3136

This is an alternative to using a cache for speeding up the CI time spent in PRs.

This approach uses a different way to resolve which packages need to be compiled and tested. The result is we get only the list of packages which sources are modified and this is what we pass to the nx run-many command.

Why nx affected -t compile compiles so many packages?

The reason is because internally the command takes in consideration nx.json dependencies on tasks. The script iterates over each package and runs the "compile" task if:

• the package itself is modified
• the compile task depends on another compile task in another package that has been modified

So nx.json is expanding the dependency graph. Now we know a bit more about the behaviour of the command.

Which solution is proposed?

The command nx affected if called without params gives a list with only the changed packages (which is what we want). Then we can pass that list to nx run-many command to narrow the list of packages that should run the given task (compile, test). Here is an example

npx nx run-many -t compile -p "@opentelemetry/instrumentation-aws-sdk" "@opentelemetry/instrumentation-undici"
   ✔  nx run @opentelemetry/instrumentation-aws-sdk:version:update (923ms)
   ✔  nx run @opentelemetry/instrumentation-undici:version:update (926ms)
   ✔  nx run @opentelemetry/contrib-test-utils:compile (3s)
   ✔  nx run @opentelemetry/instrumentation-undici:compile (3s)
   ✔  nx run @opentelemetry/instrumentation-aws-sdk:compile (3s)

you can see that the command takes care of dependencies like @opentelemetry/contrib-test-utils

[david-luna]

In https://github.com/open-telemetry/opentelemetry-js-contrib/actions/runs/19137279065/job/54692601282?pr=3208 some of the test fails because network issues in npm ci. But the list of packages on compilation and test are what I think we're looking for.

Commit 20e7409 added a change in pg instrumentation and the contrib-test-utils package has been compiled since its a dependency of the instrumentation.

[trentm]

nit: mismerge? (Same thing below)

[david-luna]

Did this change on purpose to validate the workflow was picking correctly. Will remove it before merging. Thanks for the heads up

[david-luna]

In a conversation with @trentm we agreed that this approach is not what we want in some situations. An example is if @opentelemetry/contrib-test-utils package is changed and no other then we need to run the tests for all packages that are depending on it because that change may break tests.

After that discussion I think the only packages we may want to skip compiling/testing if not changed is @opentelemetry/auto-instrumentations-node and @opentelemetry/auto-instrumentations-web so I think we could tell nx to ignore them if not modified