ViewComponent/view_component · error · ViewComponent::InvalidCollectionArgumentError

The value of the first argument passed to `with_collection`

Error message

The value of the first argument passed to `with_collection` isn't a valid collection. Make sure it responds to `to_ary`.

What it means

Error "The value of the first argument passed to `with_collection` isn't a valid collection. Make sure it responds to `to_ary`." thrown in ViewComponent/view_component.

Source

Thrown at lib/view_component/collection.rb:61

      @collection.map do |item|
        component.new(**component_options(item, iterator)).tap do |_|
          iterator.iterate!
        end
      end
    end

    def initialize(component, object, spacer_component, **options)
      @component = component
      @collection = collection_variable(object || [])
      @spacer_component = spacer_component
      @options = options
    end

    def collection_variable(object)
      if object.respond_to?(:to_ary)
        object.to_ary
      else
        raise InvalidCollectionArgumentError
      end
    end

    def component_options(item, iterator)
      item_options = @options.dup
      item_options[component.__vc_collection_parameter] = item
      item_options[component.__vc_collection_counter_parameter] = iterator.index if component.__vc_counter_argument_present?
      item_options[component.__vc_collection_iteration_parameter] = iterator.dup if component.__vc_iteration_argument_present?

      item_options
    end

    # Render the spacer through a fresh `dup` so a collection rendered multiple
    # times always gets a clean spacer instance.
    def rendered_spacer(view_context)
      return "" unless @spacer_component

      @spacer_component.dup.render_in(view_context)

View on GitHub (pinned to 9f22c36fa7)

Solutions

1. Pass an object that responds to `to_ary` (e.g. an Array or ActiveRecord::Relation) as the first argument to `with_collection`.
2. If the object is a single item, wrap it: with_collection([item]). If it is a custom enumerable, define `to_ary` or convert it with `.to_a`.

When it happens

Trigger: Thrown at lib/view_component/collection.rb:61 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of ViewComponent/view_component@9f22c36fa7 (2026-08-23). Data as JSON: /api/errors/7f2222dcf7c88e62. Report an issue: GitHub.