Axn

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RuboCop Integration ​

Axn provides a custom RuboCop cop to help enforce proper result handling when calling Actions.

What It Does ​

The Axn/UncheckedResult cop detects when you call another Action from within an Action but don't properly handle the result. This helps prevent silent failures and ensures consistent error handling patterns.

⚠️ Warning: This cop uses static analysis and cannot distinguish between actual Axn classes and other classes that happen to have a call method. If you're using legacy services or other service patterns alongside Axn, you may encounter false positives. Use RuboCop disable comments for intentional violations.

💡 Tip: If you're using the Actions namespace (see Rails Integration), you can configure the cop to only check Actions::* classes, eliminating false positives from other service objects.

Setup ​

1. Add to Your .rubocop.yml ​

yaml
require:
  - axn/rubocop

Axn/UncheckedResult:
  Enabled: true
  Severity: warning

2. Verify Installation ​

bash
bundle exec rubocop --show-cops | grep Axn

You should see Axn/UncheckedResult in the output.

Basic Usage ​

✅ Good - Using call! ​

ruby
class OuterAction
  include Axn
  def call
    InnerAction.call!(param: "value")  # Exceptions bubble up
  end
end

✅ Good - Checking the result ​

ruby
class OuterAction
  include Axn
  def call
    result = InnerAction.call(param: "value")
    return result unless result.ok?
    # Process successful result...
  end
end

❌ Bad - Ignoring the result ​

ruby
class OuterAction
  include Axn
  def call
    InnerAction.call(param: "value")  # Will trigger offense
    # This continues even if InnerAction fails
  end
end

Configuration ​

The cop supports flexible configuration:

yaml
Axn/UncheckedResult:
  Enabled: true
  CheckNested: true      # Check nested Axn calls (default: true)
  CheckNonNested: true   # Check non-nested Axn calls (default: true)
  ActionsNamespace: "Actions"  # Only check Actions::* classes (optional)
  Severity: warning      # or error

ActionsNamespace Configuration ​

When using the Actions namespace, you can configure the cop to only check calls on Actions::* classes:

yaml
Axn/UncheckedResult:
  ActionsNamespace: "Actions"

This eliminates false positives from other service objects while still catching unchecked Axn action calls:

ruby
class OuterAction
  include Axn
  def call
    SomeService.call(param: "value")        # Won't trigger cop
    Actions::InnerAction.call(param: "value")  # Will trigger cop
  end
end

For detailed configuration options, usage patterns, and troubleshooting, see the technical documentation.