| name | ash-testing |
| description | Testing Ash resources, avoiding deadlocks, and using test generators |
Testing
When testing resources:
- Test your domain actions through the code interface
- Use test utilities in
Ash.Test - Test authorization policies work as expected using
Ash.can? - Use
authorize?: falsein tests where authorization is not the focus - Write generators using
Ash.Generator - Prefer to use raising versions of functions whenever possible, as opposed to pattern matching
Preventing Deadlocks in Concurrent Tests
When running tests concurrently, using fixed values for identity attributes can cause deadlock errors. Multiple tests attempting to create records with the same unique values will conflict.
Use Globally Unique Values
Always use globally unique values for identity attributes in tests:
# BAD - Can cause deadlocks in concurrent tests
%{email: "test@example.com", username: "testuser"}
# GOOD - Use globally unique values
%{
email: "test-#{System.unique_integer([:positive])}@example.com",
username: "user_#{System.unique_integer([:positive])}",
slug: "post-#{System.unique_integer([:positive])}"
}
Creating Reusable Test Generators
For better organization, create a generator module:
defmodule MyApp.TestGenerators do
use Ash.Generator
def user(opts \\ []) do
changeset_generator(
User,
:create,
defaults: [
email: "user-#{System.unique_integer([:positive])}@example.com",
username: "user_#{System.unique_integer([:positive])}"
],
overrides: opts
)
end
end
# In your tests
test "concurrent user creation" do
users = MyApp.TestGenerators.generate_many(user(), 10)
# Each user has unique identity attributes
end
This applies to ANY field used in identity constraints, not just primary keys. Using globally unique values prevents frustrating intermittent test failures in CI environments.