add more validations around event timestamp

app/services/events/create_batch_service.rb

@@ -47,13 +47,15 @@ def validate_events
         event.external_subscription_id = event_params[:external_subscription_id]
         event.properties = event_params[:properties] || {}
         event.metadata = metadata || {}
-        event.timestamp = Time.zone.at(event_params[:timestamp] ? event_params[:timestamp].to_f : timestamp)
+        event.timestamp = Time.zone.at(event_params[:timestamp] ? Float(event_params[:timestamp]) : timestamp)
         event.precise_total_amount_cents = event_params[:precise_total_amount_cents]
 
         CalculateExpressionService.call(organization:, event:).raise_if_error!
 
         result.events.push(event)
         result.errors = result.errors.merge({index => event.errors.messages}) unless event.valid?
+      rescue ArgumentError
+        result.errors = result.errors.merge({index => {timestamp: ['invalid_format']}})
       end
     end
 

spec/requests/api/v1/events_controller_spec.rb

@@ -110,6 +110,40 @@
       expect(response).to have_http_status(:ok)
       expect(json[:events].first[:external_subscription_id]).to eq(subscription.external_id)
     end
+
+    context 'with invalid timestamp for one event' do
+      let(:batch_params) do
+        [
+          {
+            code: metric.code,
+            transaction_id: SecureRandom.uuid,
+            external_subscription_id: subscription.external_id,
+            timestamp: Time.current.to_i,
+            precise_total_amount_cents: '123.45',
+            properties: {
+              foo: 'bar'
+            }
+          },
+          {
+            code: metric.code,
+            transaction_id: SecureRandom.uuid,
+            external_subscription_id: subscription.external_id,
+            timestamp: Time.current.to_s,
+            precise_total_amount_cents: '123.45',
+            properties: {
+              foo: 'bar'
+            }
+          }
+        ]
+      end
+
+      it 'returns an error indicating which event contained which error' do
+        expect { subject }.not_to change(Event, :count)
+
+        expect(response).to have_http_status(:unprocessable_entity)
+        expect(json[:error_details]).to eq({'1': {timestamp: ["invalid_format"]}})
+      end
+    end
   end
 
   describe 'GET /api/v1/events' do

spec/services/events/validate_creation_service_spec.rb

@@ -254,5 +254,31 @@
         end
       end
     end
+
+    context 'when timestamp is in a wrong format' do
+      let(:params) do
+        {external_customer_id: customer.external_id, code: billable_metric.code, transaction_id:, timestamp: '2025-01-01'}
+      end
+
+      it 'returns a timestamp_is_not_valid error' do
+        validate_event
+
+        expect(result).not_to be_success
+        expect(result.error).to be_a(BaseService::ValidationFailure)
+        expect(result.error.messages.keys).to include(:timestamp)
+        expect(result.error.messages[:timestamp]).to include('invalid_format')
+      end
+    end
+
+    context 'when timestamp is valid' do
+      let(:params) do
+        {external_customer_id: customer.external_id, code: billable_metric.code, transaction_id:, timestamp: Time.current.to_i + 0.11}
+      end
+
+      it 'does not raise any errors' do
+        expect(validate_event).to be_nil
+        expect(result).to be_success
+      end
+    end
   end
 end