Return matches as children of tournament

app/controllers/matches_controller.rb

@@ -4,6 +4,12 @@ class MatchesController < ApplicationController
   before_action :set_match, only: %i[show update]
   before_action :validate_params, only: %i[update]
   before_action -> { require_owner! @match.owner }, only: %i[update]
+  before_action :set_tournament, only: %i[index]
+
+  # GET/tournaments/1/matches
+  def index
+    render json: @tournament.matches, each_serializer: MatchSerializer
+  end
 
   # GET /matches/1
   def show
@@ -61,6 +67,10 @@ class MatchesController < ApplicationController
     @match = Match.find(params[:id])
   end
 
+  def set_tournament
+    @tournament = Tournament.find(params[:tournament_id])
+  end
+
   def match_params
     params.slice(:state).permit!
   end

config/routes.rb

@@ -13,6 +13,7 @@ Rails.application.routes.draw do
   resources :teams, only: %i[show update]
   resources :tournaments do
     resources :statistics, only: %i[index]
+    resources :matches, only: %i[index]
   end
   resources :match_scores, only: %i[show update]
   resources :groups, only: %i[show]