Inertia Rails Testing Testing patterns for Inertia responses with RSpec and Minitest. For each controller action, verify: Correct component → render_component('users/index') Expected props → have_props(users: satisfy { ... }) No leaked data → have_no_prop(:secret) Flash messages → follow_redirect! then have_flash(notice: '...') Deferred props → have_deferred_props(:analytics) Common mistake: Forgetting follow_redirect! after PRG — without it, you're asserting against the 302 redirect response, not the Inertia page that follows. Setup

spec/rails_helper.rb

require 'inertia_rails/rspec' RSpec Matchers Matcher Purpose be_inertia_response Verify response is Inertia format render_component('path') Check rendered component name have_props(key: value) Partial props match have_exact_props(key: value) Exact props match have_no_prop(:key) Assert prop absent have_flash(key: value) Partial flash match have_exact_flash(key: value) Exact flash match have_no_flash(:key) Assert flash absent have_deferred_props(:key) Check deferred props exist have_view_data(key: value) Partial view_data match RSpec Examples ALWAYS use matchers ( render_component , have_props , have_flash ) instead of direct property access ( inertia.component , inertia.props[:key] ):

BAD — direct property access:

expect(inertia.component).to eq('users/index')

expect(inertia.props[:users].length).to eq(3)

GOOD — use matchers:

expect ( inertia ) . to render_component ( 'users/index' ) expect ( inertia ) . to have_props ( users : satisfy { | u | u . length == 3 } )

Key pattern: follow_redirect! after POST/PATCH/DELETE before asserting

it 'redirects with flash on success' do post users_path , params : { user : valid_params } expect ( response ) . to redirect_to ( users_path ) follow_redirect ! expect ( inertia ) . to have_flash ( notice : 'User created!' ) end it 'returns validation errors on failure' do post users_path , params : { user : { name : '' } } follow_redirect ! expect ( inertia ) . to have_props ( errors : hash_including ( 'name' => anything ) ) end Test Shared Props Shared props from inertia_share are included in inertia.props . The inertia helper is available in type: :request specs after requiring inertia_rails/rspec : it 'includes shared auth data' do sign_in ( user ) get dashboard_path expect ( inertia ) . to have_props ( auth : hash_including ( user : hash_including ( id : user . id ) ) ) end it 'excludes auth data for unauthenticated users' do get dashboard_path expect ( inertia ) . to have_props ( auth : hash_including ( user : nil ) ) end Test Deferred Props it 'defers expensive analytics data' do get dashboard_path expect ( inertia ) . to have_deferred_props ( :analytics , :statistics ) expect ( inertia ) . to have_deferred_props ( :slow_data , group : :slow ) end Partial Reload Helpers it 'supports partial reload' do get users_path

Simulate partial reload — only fetch specific props

inertia_reload_only ( :users , :pagination )

Or exclude specific props

inertia_reload_except ( :expensive_stats )

Load deferred props

inertia_load_deferred_props ( :default ) inertia_load_deferred_props

loads all groups

end Test External Redirects (inertia_location) it 'redirects to Stripe via inertia_location' do post checkout_path

inertia_location returns 409 with X-Inertia-Location header

expect ( response ) . to have_http_status ( :conflict ) expect ( response . headers [ 'X-Inertia-Location' ] ) . to match ( /stripe.com/ ) end NEVER Test These Inertia framework behavior — don't test that

sends CSRF tokens or that router.visit works. Test YOUR controller logic. Exact prop structure — use have_props(users: satisfy { ... }) , not deep equality on full JSON. Brittle tests break when you add a column. Flash without follow_redirect! — after POST/PATCH/DELETE with redirect, you MUST follow_redirect! before asserting flash or props. Without it you're asserting against the 302, not the page. Deferred prop values on initial load — deferred props are nil in the initial response because they're fetched in a separate request after page render. Use have_deferred_props(:key) to verify they're registered, or inertia_load_deferred_props to resolve them in tests. Mocked Inertia responses — use type: :request specs that exercise the full stack. type: :controller specs with assigns don't work because Inertia uses a custom render pipeline that only executes in the full request cycle. Direct Access (use matchers above when possible) inertia . component # => 'users/index' inertia . props # => { users: [...] } inertia . props [ :users ] # direct prop access inertia . flash # => { notice: 'Created!' } inertia . deferred_props # => { default: [:analytics], slow: [:report] }

inertia-rails-testing

安装