Handle multiple kind of requests in GraphQL controller

* Added support for GET requests
* Added support for application/graphql content-type for POST requests
* Handling query string parsing errors in controller
* Wrote specs for all this

app/controllers/graphql_controller.rb

@@ -4,11 +4,25 @@ class GraphqlController < ApplicationController
   skip_authorization_check
 
   def query
-    # ConsulSchema.execute returns the query result in the shape of a Hash, which
-    # is sent back to the client rendered in JSON
-    render json: ConsulSchema.execute(
-      params[:query],
+
+    if request.headers["CONTENT_TYPE"] == 'application/graphql'
+      query_string = request.body.string  # request.body.class => StringIO
+    else
+      query_string = params[:query]
+    end
+
+    if query_string.nil?
+      render json: { message: 'Query string not present' }, status: :bad_request
+    else
+      begin
+        response = ConsulSchema.execute(
+          query_string,
           variables: params[:variables] || {}
         )
+        render json: response, status: :ok
+      rescue GraphQL::ParseError
+        render json: { message: 'Query string is not valid JSON' }, status: :bad_request
+      end
+    end
   end
 end

config/routes.rb

@@ -264,6 +264,7 @@ Rails.application.routes.draw do
 
   # GraphQL
   mount GraphiQL::Rails::Engine, at: '/graphiql', graphql_path: '/graphql'
+  get '/graphql', to: 'graphql#query'
   post '/graphql', to: 'graphql#query'
 
   if Rails.env.development?

spec/controllers/graphql_controller_spec.rb

@@ -1,90 +1,56 @@
 require 'rails_helper'
 
-# Hacerlo como los test de controlador de rails
+# Useful resource: http://graphql.org/learn/serving-over-http/
 
 describe GraphqlController, type: :request do
   let(:proposal) { create(:proposal) }
 
-  it "answers simple json queries" do
-    headers = { "CONTENT_TYPE" => "application/json" }
-    #post "/widgets", '{ "widget": { "name":"My Widget" } }', headers
-    post '/graphql', { query: "{ proposal(id: #{proposal.id}) { title } }" }.to_json, headers
-    expect(response).to have_http_status(200)
+  describe "handles GET request" do
+    specify "with query string inside query params" do
+      get '/graphql', query: "{ proposal(id: #{proposal.id}) { title } }"
+      expect(response).to have_http_status(:ok)
       expect(JSON.parse(response.body)['data']['proposal']['title']).to eq(proposal.title)
     end
 
-  
+    specify "with malformed query string" do
+      get '/graphql', query: 'Malformed query string'
+      expect(response).to have_http_status(:bad_request)
+      expect(JSON.parse(response.body)['message']).to eq('Query string is not valid JSON')
     end
 
-=begin
-describe GraphqlController do
-  let(:uri) { URI::HTTP.build(host: 'localhost', path: '/graphql', port: 3000) }
-  let(:query_string) { "" }
-  let(:body) { {query: query_string}.to_json }
-
-  describe "POST requests" do
-    let(:author) { create(:user) }
-    let(:proposal) { create(:proposal, author: author) }
-    let(:response) { HTTP.headers('Content-Type' => 'application/json').post(uri, body: body) }
-    let(:response_body) { JSON.parse(response.body) }
-
-    context "when query string is valid" do
-      let(:query_string) { "{ proposal(id: #{proposal.id}) { title, author { username } } }" }
-      let(:returned_proposal) { response_body['data']['proposal'] }
-
-      it "returns HTTP 200 OK" do
-        expect(response.code).to eq(200)
-      end
-
-      it "returns first-level fields" do
-        expect(returned_proposal['title']).to eq(proposal.title)
-      end
-
-      it "returns nested fields" do
-        expect(returned_proposal['author']['username']).to eq(author.username)
+    specify "without query string" do
+      get '/graphql'
+      expect(response).to have_http_status(:bad_request)
+      expect(JSON.parse(response.body)['message']).to eq('Query string not present')
     end
   end
 
-    context "when query string asks for invalid fields" do
-      let(:query_string) { "{ proposal(id: #{proposal.id}) { missing_field } }" }
+  describe "handles POST request" do
+    let(:json_headers) { { "CONTENT_TYPE" => "application/json" } }
 
-      it "returns HTTP 200 OK" do
-        expect(response.code).to eq(200)
+    specify "with json-encoded query string inside body" do
+      post '/graphql', { query: "{ proposal(id: #{proposal.id}) { title } }" }.to_json, json_headers
+      expect(response).to have_http_status(:ok)
+      expect(JSON.parse(response.body)['data']['proposal']['title']).to eq(proposal.title)
     end
 
-      it "doesn't return any data" do
-        expect(response_body['data']).to be_nil
+    specify "with raw query string inside body" do
+      graphql_headers = { "CONTENT_TYPE" => "application/graphql" }
+      post '/graphql', "{ proposal(id: #{proposal.id}) { title } }", graphql_headers
+      expect(response).to have_http_status(:ok)
+      expect(JSON.parse(response.body)['data']['proposal']['title']).to eq(proposal.title)
     end
 
-      it "returns error inside body" do
-        expect(response_body['errors']).to be_present
-      end
+    specify "with malformed query string" do
+      post '/graphql', { query: "Malformed query string" }.to_json, json_headers
+      expect(response).to have_http_status(:bad_request)
+      expect(JSON.parse(response.body)['message']).to eq('Query string is not valid JSON')
     end
 
-    context "when query string is not valid" do
-      let(:query_string) { "invalid" }
-
-      it "returns HTTP 400 Bad Request" do
-        expect(response.code).to eq(400)
+    it "without query string" do
+      post '/graphql', json_headers
+      expect(response).to have_http_status(:bad_request)
+      expect(JSON.parse(response.body)['message']).to eq('Query string not present')
     end
   end
-
-    context "when query string is missing" do
-      let(:query_string) { nil }
-
-      it "returns HTTP 400 Bad Request" do
-        expect(response.code).to eq(400)
 end
-    end
-
-    context "when body is missing" do
-      let(:body) { nil }
-
-      it "returns HTTP 400 Bad Request" do
-        expect(response.code).to eq(400)
-      end
-    end
-
-  end
-end
-=end