Add grape endpoint to update an artwork

app/api/using_grape/artworks_endpoint.rb

@@ -20,6 +20,16 @@ class ArtworksEndpoint < Grape::API
           error! errors, 400
         end
       end
+
+      put ":id" do
+        artwork = Artwork.find(params[:id])
+        if artwork.update(params)
+          artwork
+        else
+          errors = {errors: artwork.errors.full_messages.to_sentence}
+          error! errors, 400
+        end
+      end
     end
   end
 end

spec/requests/using_grape/update_artwork_spec.rb

@@ -0,0 +1,46 @@
+require "rails_helper"
+
+describe "PUT /api/using_grape/artworks/:id" do
+  let(:artwork) { FactoryBot.create(:artwork, title: "Fooncy cup") }
+
+  context "with invalid update" do
+    it "returns 400 and the errors" do
+      params = {title: ""}
+
+      put "/api/using_grape/artworks/#{artwork.id}", params: params
+
+      expect(response.status).to eq 400
+      expect(response.parsed_body.key?("errors")).to eq true
+    end
+  end
+
+  context "with partial update" do
+    it "returns 200 and that updated artwork" do
+      params = {title: "Fancy cup"}
+
+      put "/api/using_grape/artworks/#{artwork.id}", params: params
+
+      expect(response.status).to eq 200
+      expect(response.parsed_body["title"]).to eq "Fancy cup"
+    end
+  end
+
+  context "with full update" do
+    it "returns a 200 and that updated artwork" do
+      params = {
+        amount_cents: 100_000,
+        artist_name: "Sally Sculptor",
+        medium: "Clay",
+        title: "Fancy cup"
+      }
+
+      put "/api/using_grape/artworks/#{artwork.id}", params: params
+
+      expect(response.status).to eq 200
+      expect(response.parsed_body["amount_cents"]).to eq 100_000
+      expect(response.parsed_body["artist_name"]).to eq "Sally Sculptor"
+      expect(response.parsed_body["medium"]).to eq "Clay"
+      expect(response.parsed_body["title"]).to eq "Fancy cup"
+    end
+  end
+end