Plan 02: FilterDropdownComponent & SourcesIndexPresenter

Objective

Extract duplicated filter dropdown markup from 3 index views into a shared FilterDropdownComponent (V5), extract filter state logic from sources/index.html.erb into a SourcesFilterPresenter (V1), document row preload requirements (V3), and standardize Turbo Frame naming (V12).

Context

• @.claude/skills/viewcomponent-patterns/SKILL.md -- ViewComponent patterns with TDD
• @.claude/skills/rails-presenter/SKILL.md -- Presenter extraction with BasePresenter
• @.claude/skills/tdd-cycle/SKILL.md -- TDD red-green-refactor workflow
• @.claude/skills/hotwire-patterns/SKILL.md -- Turbo Frame naming and patterns
• @.claude/skills/sm-architecture/SKILL.md -- Engine architecture and module tree
• app/views/source_monitor/sources/index.html.erb (282 lines) -- has 56 lines of filter logic (V1) and repeated filter selects (V5)
• app/views/source_monitor/items/index.html.erb -- same filter dropdown pattern
• app/views/source_monitor/logs/index.html.erb -- same filter dropdown pattern
• app/views/source_monitor/sources/_row.html.erb -- undocumented preload requirements (V3)
• Filter selects share identical Tailwind classes, onchange="this.form.requestSubmit()" behavior, and label styling

Tasks

Task 1: Write FilterDropdownComponent test (TDD red) and implement

Create test/components/source_monitor/filter_dropdown_component_test.rb:

• Test renders label text
• Test renders select with correct param name
• Test renders options with correct values
• Test marks selected option when selected_value matches
• Test includes onchange="this.form.requestSubmit()" for auto-submit
• Test renders consistent Tailwind styling classes

Create app/components/source_monitor/filter_dropdown_component.rb:

• initialize(label:, param_name:, options:, selected_value: nil, form: nil)
• call method renders label + select with Tailwind styling
• Auto-submit via onchange attribute

Create app/components/source_monitor/filter_dropdown_component.html.erb (or use inline call).

Note: If ViewComponent gem is not yet in the gemspec, add view_component to source_monitor.gemspec as a runtime dependency. Create app/components/source_monitor/application_component.rb base class.

Task 2: Write SourcesFilterPresenter test (TDD red) and implement

Create test/presenters/source_monitor/sources_filter_presenter_test.rb:

• Test has_any_filter? returns false when no filters active
• Test has_any_filter? returns true when search term present
• Test has_any_filter? returns true when dropdown filter active
• Test active_filter_keys returns only keys with present values
• Test filter_labels returns hash with humanized labels for active filters
• Test adapter_options returns distinct scraper adapter values

Create app/presenters/source_monitor/sources_filter_presenter.rb:

• initialize(search_params:, search_term:, fetch_interval_filter:, adapter_options:)
• Extract filter logic from sources/index.html.erb lines 57-106
• Methods: has_any_filter?, active_filter_keys, filter_labels, clear_filter_path(key, current_params)

Task 3: Update sources/index.html.erb to use component and presenter

Modify app/views/source_monitor/sources/index.html.erb:

• Replace inline filter selects with render SourceMonitor::FilterDropdownComponent.new(...)
• Replace filter state logic (lines 57-106) with @filter_presenter method calls
• Move adapter_options query from template to controller (assign to presenter)
• Ensure import_session_step frame ID is renamed to source_monitor_import_step if present (V12)

Modify app/controllers/source_monitor/sources_controller.rb (index action only):

• Query adapter_options in controller
• Build @filter_presenter = SourceMonitor::SourcesFilterPresenter.new(...) with search params
• Add code comment documenting row partial preload requirements (V3): item_activity_rates, avg_feed_word_counts, avg_scraped_word_counts

Task 4: Update items and logs index views to use FilterDropdownComponent

Modify app/views/source_monitor/items/index.html.erb:

• Replace inline filter selects with render SourceMonitor::FilterDropdownComponent.new(...)

Modify app/views/source_monitor/logs/index.html.erb:

• Replace inline filter selects with render SourceMonitor::FilterDropdownComponent.new(...)

Task 5: Verify

• bin/rails test test/components/ -- all component tests pass
• bin/rails test test/presenters/source_monitor/sources_filter_presenter_test.rb -- all pass
• bin/rails test test/controllers/ -- all controller tests pass
• bin/rails test -- full suite passes
• bin/rubocop -- zero offenses