Bylaw.Credo

Custom Credo checks.

Installation

Downstream applications should typically include this package only in development and test:

{:bylaw_credo, "== 0.3.0", only: [:dev, :test], runtime: false}

Usage

Configure Bylaw Credo checks through Credo's normal .credo.exs API. Add each check you want by listing its fully qualified module in the checks: list:

%{
  configs: [
    %{
      name: "default",
      plugins: [
        {Bylaw.Credo.Plugin.HEExSources, []}
      ],
      checks: [
        {Bylaw.Credo.Check.Elixir.DocBeforeSpec, []},
        {Bylaw.Credo.Check.Elixir.NoRemoteCallsInModuleAttributes, []},
        {Bylaw.Credo.Check.Elixir.PreferEmptyListChecks, []},
        {Bylaw.Credo.Check.HEEx.DesignSystem.NoArbitrarySpacing, []},
        {Bylaw.Credo.Check.Elixir.PreferBlockIf, []},
        {Bylaw.Credo.Check.Elixir.SimpleTaggedTupleValues, []},
        {Bylaw.Credo.Check.Ecto.NoDataChangesInSchemaMigrations, []},
        {Bylaw.Credo.Check.Ecto.PreferRepoOneOverAllFirst, []},
        {Bylaw.Credo.Check.HEEx.NoDuplicateStaticIds, []},
        {Bylaw.Credo.Check.HEEx.NoIndirectAssignAccess, []},
        {Bylaw.Credo.Check.HEEx.NoElementSpacing, []},
        {Bylaw.Credo.Check.HEEx.PreferNativeInteractiveElement, []},
        {Bylaw.Credo.Check.HEEx.PreferLinkForNavigation, []},
        {Bylaw.Credo.Check.HEEx.RequireAccessibleButtonText, []},
        {Bylaw.Credo.Check.HEEx.NoJavascriptHref, []},
        {Bylaw.Credo.Check.HEEx.RequireButtonType, []},
        {Bylaw.Credo.Check.HEEx.RequireImageAlt, []},
        {Bylaw.Credo.Check.HEEx.RequireLabelForInput, []},
        {Bylaw.Credo.Check.HEEx.RequireLoadingStateForSubmit, []},
        {Bylaw.Credo.Check.HEEx.RequireLinkHref, []},
        {Bylaw.Credo.Check.HEEx.RequireLinkText, []},
        {Bylaw.Credo.Check.HEEx.RequireTargetBlankRel, []},
        {Bylaw.Credo.Check.PhoenixLiveView.RequireFunctionComponentAttrs, []},
        {Bylaw.Credo.Check.Elixir.PreferListTypeSyntax, []},
        {Bylaw.Credo.Check.Testing.NoDescribeBlocks, []},
        {Bylaw.Credo.Check.Testing.PreferSelectorAssertionsForHtml, []}
      ]
    }
  ]
}

See each check module's documentation for its examples, notes, options, and check-specific .credo.exs usage.

Bylaw.Credo.Check.HEEx.NoIndirectAssignAccess reports literal-key Map.get(assigns, key) and assigns[key] access in HEEx templates. Initialize assigns before rendering and access them directly with @key so missing values and defaults are handled at the rendering boundary.

Bylaw.Credo.Check.HEEx.DesignSystem.NoArbitrarySpacing reports raw pixel spacing values in static Tailwind classes and CSS margin or padding declarations. Use design-system spacing tokens instead.

Bylaw.Credo.Check.Elixir.NoRemoteCallsInModuleAttributes reports calls into application and dependency modules from module attributes because those calls execute during compilation and embed their results in the consumer. Literal values and Elixir or OTP standard-library calls are accepted by default.

Bylaw.Credo.Check.Ecto.NoDataChangesInSchemaMigrations reports direct Repo row mutations and literal INSERT, UPDATE, DELETE, or MERGE SQL in Ecto schema migrations. It is a best-effort guideline that points operational data changes toward reviewed, resumable data-migration scripts or release tasks.

Bylaw.Credo.Check.HEEx.PreferLinkForNavigation enforces link semantics for durable navigation. It reports explicit LiveView navigation commands wired through phx-click on HEEx tags and components, so navigation uses real links instead of click handlers on other elements.