Docs
Getting started
CLI
Plugins
Community
Nx Cloud
Nx Consulting
Tutorial total points: 0 / 92

Step 11: Test Affected Projects

Video of this Lesson

Because Nx understands the dependency graph of your workspace, Nx can be efficient at retesting and rebuilding your projects.

Commit all the changes in the repo:

git add .
git commit -am 'init'
git checkout -b testbranch

Open libs/ui/src/lib/todos/todos.component.html and change the template:

<ul>
  <li *ngFor="let t of todos">{{ t.title }}!</li>
</ul>

Run npm run affected:apps, and you should see todos printed out. The affected:apps looks at what you have changed and uses the dependency graph to figure out which apps can be affected by this change.

Run npm run affected:libs, and you should see ui printed out. This command works similarly, but instead of printing the affected apps, it prints the affected libs.

Test Affected Projects

Printing the affected projects can be handy, but usually you want to do something with them. For instance, you may want to test everything that has been affected.

Run npx nx affected:test to retest only the projects affected by the change.

You will see the following:

>  NX  Running target test for projects:

  - ui
  - todos

...

  Failed projects:

  - todos
  - ui

Note that Nx only tried to retest ui and todos. It didn't retest api or data because there is no way that could be affected by the changes in this branch.

Run npm run affected:test -- --only-failed to retest the failed projects.

Affected:*

You can run any target against the affected projects in the graph like this:

# The following are equivalent
npx nx affected --target=build
npx nx affected:build

Quiz

Run "npx nx affected --target=invalid --base=master". What do you see?

  • No projects to run test

  • The todos project failed as before

  • Cannot run tests against master error