Rails Test “ActionController::UnknownFormat: is missing a template for this request format and variant”

Question

I'm creating a testing suite for a Twitter clone app called "Canary" and I'm having a hard time writing integration tests for chirps#reply and chirps#rechirps

Chirps Controller

def reply
    @chirp = current_user.chirps.new
    @parent = Chirp.find_by(id: params[:parent_id])
    @chirp.parent_id = params[:parent_id]
    respond_to do |format|
        format.js
        format.html
    end
end

def rechirp
    @chirp = current_user.chirps.new
    @reference = Chirp.find_by(id: params[:reference_id])
    @chirp.reference_id = params[:reference_id]
    respond_to do |format|
        format.js
        format.html
    end 
end

Chirp View

<%= link_to reply_chirp_path(current_user, parent_id: chirp.id), remote: true, data: { target: '#modal_container', toggle: 'modal' } do %>
    <%= icon('far', 'comment') %> <%= chirp.children.size if chirp.children.size > 0 %>
<% end %>

<%= link_to rechirp_chirp_path(current_user, reference_id: chirp.id), remote: true, data: { target: '#modal_container', toggle: 'modal' } do %>
    <%= icon('fas', 'retweet') %> <%= count_rechirps(chirp) %>
<% end %>

Reply.js.erb

$("#modal_container").find(".modal-content").html("<%= j render 'chirps/modal_reply' %>");
$("#modal_container").modal('show', 'focus');

Rechirp.js.erb

$("#modal_container").find(".modal-content").html("<%= j render 'chirps/modal_rechirp' %>");
$("#modal_container").modal('show', 'focus');

Chirps Interface Test

# Try to reply to chirp
assert_select 'a[href=?]', reply_chirp_path(@user, parent_id: @chirp.id)
assert_difference 'Chirp.count', 1 do
    get reply_chirp_path(@user, parent_id: @chirp)
    assert_select 'div#modal_container > div.modal-dialog > div.modal-content > div.modal-body'
    post chirps_path, params: { chirp: { content: content, parent_id: @chirp.id } }
    assert :success
end
assert_redirected_to root_url
follow_redirect!
# Try to rechirp chirp
assert_select 'a[href=?]', rechirp_chirp_path(@user, reference_id: @chirp.id)

When I run chirp_interface_test.rb I keep encountering the same error:

Error: ChirpsInterfaceTest#test_chirp_interface:

ActionController::UnknownFormat: ChirpsController#reply is missing a template for this request format and variant.

request.formats: ["text/html"]

request.variant: []

 test/integration/chirps_interface_test.rb:30:in `block (2 levels) in <class:ChirpsInterfaceTest>' test/integration/chirps_interface_test.rb:29:in `block in <class:ChirpsInterfaceTest>' 

I know that the routes work in app because I've successfully submitted by replies and rechirps multiple times through the localhost. How can I test that these actions work properly with rails testing?

Answer 1

Error: ChirpsInterfaceTest#test_chirp_interface:

ActionController::UnknownFormat: ChirpsController#reply is missing a template for this request format and variant.

request.formats: ["text/html"]

request.variant: []

Your links have remote: true . That means the request is JS . To test such links, you should use xhr: true like so

get reply_chirp_path(@user, parent_id: @chirp), xhr: true

Since you haven't specified this, the request is treated as HTML and fails with that exception.

For more info, read Testing XHR (AJAX) requests