Fixing Flaky Deprecated Annotation Unit Tests In Serverpod

Intermittent failures in unit tests can be a major headache for developers. They introduce uncertainty into the development process, making it difficult to determine whether code changes are truly stable. This article dives into a specific case of a flaky unit test in Serverpod related to the deprecated annotation. We'll explore the error, analyze the potential causes, and discuss strategies for resolving it.

Understanding the Issue: Intermittent Failures

Flaky tests, also known as intermittent tests, are unit tests that sometimes pass and sometimes fail without any changes to the code being tested. This unpredictable behavior can be caused by various factors, such as timing issues, resource contention, or external dependencies. Identifying and fixing flaky tests is crucial for maintaining a reliable and efficient development pipeline.

In the context of Serverpod, a Dart framework for building scalable server-side applications, a flaky unit test has been observed in the generation of deprecated annotations in clients. This means that the test, which should consistently pass or fail, exhibits inconsistent behavior. Let's examine the error logs to understand the problem better.

Error Log Analysis

The error logs provide valuable insights into the nature of the failure. Here’s a breakdown of the relevant information:

SERVERPOD initiating shutdown, time: 2025-11-26 07:23:28.307509Z
SERVERPOD shutdown completed, time: 2025-11-26 07:23:28.307509Z
SERVERPOD version: 3.0.0-rc.2, dart: 3.10.1 (stable) (Tue Nov 18 11:02:31 2025 -0800) on "windows_x64", time: 2025-11-26 07:23:28.681391Z
runMode: development
serverId: default
role: monolith
loggingMode: normal
applyMigrations: false
applyRepairMigration: false
SERVERPOD initialized, time: 2025-11-26 07:23:28.798817Z
2025-11-26 07:23:28.855493Z WebServer  INFO: Webserver listening on http://localhost:62654
+608: test\server_port_test.dart: Given a server with all services running on port zero then insights server reports actual port
  Skip: Skipped because insights requires a database. But it uses the same implementation as the `server.server` so if that works, this works.
SERVERPOD initiating shutdown, time: 2025-11-26 07:23:28.867137Z
SERVERPOD shutdown completed, time: 2025-11-26 07:23:28.883037Z
+622 ~1: All tests passed!

==== Running tests in ./tools/serverpod_cli ====
+3167 -1: test\integration\analyzer\dart\endpoint_validation\endpoint_method_test.dart: Given a valid endpoint method with "@Deprecated(<string literal>)" annotation then endpoint definition is created. [E]
  Expected: an object with length of <1>
    Actual: []
     Which: has length of <0>
  
  package:matcher                                                                      expect
  test\integration\analyzer\dart\endpoint_validation\endpoint_method_test.dart 1079:9  main.<fn>.<fn>
  
+3167 -2: test\integration\analyzer\dart\endpoint_validation\endpoint_method_test.dart: Given a valid endpoint method with "@Deprecated(<string literal>)" annotation then endpoint definition method has expected annotations. [E]
  Expected: <1>
    Actual: <null>
  
  package:matcher                                                                      expect
  test\integration\analyzer\dart\endpoint_validation\endpoint_method_test.dart 1085:9  main.<fn>.<fn>
  
+3702 -2: Some tests failed.

Consider enabling the flag chain-stack-traces to receive more detailed exceptions.
For example, 'dart test --chain-stack-traces'.

The key error messages are: