AshCredo

Unofficial static code analysis checks for the Ash Framework, built as a Credo plugin.

AshCredo detects common anti-patterns, security pitfalls, and missing best practices in your Ash resources and domains by analysing unexpanded source AST.

[!WARNING] This project is experimental and might break frequently.

Installation

Add ash_credo to your list of dependencies in mix.exs:

def deps do
  [
    {:ash_credo, github: "leonqadirie/ash_credo", only: [:dev, :test], runtime: false}
  ]
end

Then fetch the dependency:

mix deps.get

Setup

With Igniter

If your project uses Igniter, you can set up AshCredo automatically:

mix ash_credo.install

This will create or update your .credo.exs to include the AshCredo plugin.

Manual

Register the plugin in your .credo.exs configuration:

%{
  configs: [
    %{
      name: "default",
      plugins: [{AshCredo, []}]
    }
  ]
}

That's it. All 18 checks are enabled by default. Run Credo as usual:

mix credo

To also include low-priority checks (such as MissingCodeInterface, ActionMissingDescription, and LargeResource), use strict mode:

mix credo --strict

Checks

Check Category Priority Description
AuthorizerWithoutPolicies Warning High Detects resources with Ash.Policy.Authorizer but no policies defined
MissingChangeWrapper Warning High Flags builtin change functions (manage_relationship, set_attribute, ...) used without change wrapper in actions
MissingPrimaryKey Warning High Ensures resources with data layers have a primary key
OverlyPermissivePolicy Warning High Flags unscoped authorize_if always() policies
PinnedTimeInExpression Warning High Flags ^Date.utc_today() / ^DateTime.utc_now() in Ash expressions (frozen at compile time)
SensitiveAttributeExposed Warning High Flags sensitive attributes (password, token, secret, ...) not marked sensitive?: true
SensitiveFieldInAccept Warning High Flags privilege-escalation fields (is_admin, permissions, ...) in accept lists
WildcardAcceptOnAction Warning High Detects accept :* on create/update actions (mass-assignment risk)
EmptyDomain Warning Normal Flags domains with no resources registered
MissingDomain Warning Normal Ensures non-embedded resources set the domain: option
NoActions Warning Normal Flags resources with data layers but no actions defined
MissingCodeInterface Design Low Suggests adding a code_interface for resources with actions
MissingIdentity Design Normal Suggests identities for attributes like email, username, slug
MissingPrimaryAction Design Normal Flags missing primary?: true when multiple actions of the same type exist
MissingTimestamps Design Normal Suggests adding timestamps() to persisted resources
ActionMissingDescription Readability Low Flags actions without a description
BelongsToMissingAllowNil Readability Normal Flags belongs_to without explicit allow_nil?
LargeResource Refactor Low Flags resource files exceeding 400 lines

Configuration

Checks are registered under the extra category. You can disable individual checks or customise their parameters in .credo.exs:

%{
  configs: [
    %{
      name: "default",
      plugins: [{AshCredo, []}],
      checks: %{
        extra: [
          # Disable a check
          {AshCredo.Check.Design.MissingCodeInterface, false},

          # Set priority (can also be false to disable)
          {AshCredo.Check.Warning.NoActions, [priority: :low]},

          # Customise parameters
          {AshCredo.Check.Refactor.LargeResource, [max_lines: 250]},
          {AshCredo.Check.Warning.SensitiveAttributeExposed, [
            sensitive_names: ~w(password token secret api_key)a
          ]},
          {AshCredo.Check.Warning.SensitiveFieldInAccept, [
            dangerous_fields: ~w(is_admin role permissions)a
          ]},
          {AshCredo.Check.Design.MissingIdentity, [
            identity_candidates: ~w(email username slug)a
          ]}
        ]
      }
    }
  ]
}

Configurable parameters

The following checks accept custom parameters:

Check Parameter Default Description
Design.MissingIdentityidentity_candidates~w(email username slug handle phone)a Attribute names to suggest adding identities for
Refactor.LargeResourcemax_lines400 Maximum line count before triggering
Warning.SensitiveAttributeExposedsensitive_names~w(password hashed_password password_hash token secret api_key private_key ssn)a Attribute names to flag when not marked sensitive?: true
Warning.SensitiveFieldInAcceptdangerous_fields~w(is_admin admin permissions api_key secret_key)a Field names to flag when found in accept lists

Contributing

  1. Fork the repository
  2. Create your feature branch (git switch -c my-new-check)
  3. Apply formatting and make sure tests and lints pass (mix format, mix credo, mix test)
  4. Commit your changes
  5. Open a pull request

License

MIT - see LICENSE for details.