Fix webfinger returning wrong status code on malformed or missing param (#13759)

Fixes #13757

spec/controllers/well_known/webfinger_controller_spec.rb

@@ -84,5 +84,15 @@ PEM
 
       expect(response).to have_http_status(:not_found)
     end
+
+    it 'returns http bad request when not given a resource parameter' do
+      get :show, params: { }, format: :json
+      expect(response).to have_http_status(:bad_request)
+    end
+
+    it 'returns http bad request when given a nonsense parameter' do
+      get :show, params: { resource: 'df/:dfkj' }
+      expect(response).to have_http_status(:bad_request)
+    end
   end
 end

spec/lib/webfinger_resource_spec.rb

@@ -39,7 +39,7 @@ describe WebfingerResource do
 
         expect {
           WebfingerResource.new(resource).username
-        }.to raise_error(ActiveRecord::RecordNotFound)
+        }.to raise_error(WebfingerResource::InvalidRequest)
       end
 
       it 'finds the username in a valid https route' do
@@ -123,5 +123,15 @@ describe WebfingerResource do
         expect(result).to eq 'alice'
       end
     end
+
+    describe 'with a nonsense resource' do
+      it 'raises InvalidRequest' do
+        resource = 'df/:dfkj'
+
+        expect {
+          WebfingerResource.new(resource).username
+        }.to raise_error(WebfingerResource::InvalidRequest)
+      end
+    end
   end
 end