Adam Jež adamjez

A Test Failure That Looked Like a Race Condition

Generated by Opus 4.6

The Symptom

Our integration tests started failing. Not all of them, not consistently, and not when run individually. Only when multiple tests ran together, some would fail - some with unexpected HTTP status codes, others with assertion errors where the API returned different data than expected.

It looked like a classic race condition. It appeared out of nowhere. It worked on other developers' machines. It worked in CI pipelines. Only my local machine was affected.

public static class Program
{
    public static void Main(DotvvmResourceRepository resources)
    {
        // -----------------------------------------
        // ------------------ OLD ------------------
        // -----------------------------------------
        resources.Register("FeatureSamples_Resources_CdnScriptPriority", new ScriptResource {
            Location = new FileResourceLocation("~/Scripts/testResource.js"),

BenchmarkDotNet=v0.10.5, OS=ubuntu 16.04
Processor=Intel Xeon CPU E5-2660 0 2.20GHz, ProcessorCount=2
Frequency=1000000000 Hz, Resolution=1.0000 ns, Timer=UNKNOWN
dotnet cli version=2.0.0-preview2-005905
  [Host]     : .NET Core 4.6.25226.02, 64bit RyuJIT
  DefaultJob : .NET Core 4.6.25226.02, 64bit RyuJIT

BenchmarkDotNet=v0.10.5, OS=ubuntu 16.04
Processor=Intel Xeon CPU E5-2660 0 2.20GHz, ProcessorCount=2
Frequency=1000000000 Hz, Resolution=1.0000 ns, Timer=UNKNOWN
dotnet cli version=1.0.3
  [Host]     : .NET Core 4.6.25009.03, 64bit RyuJIT
  DefaultJob : .NET Core 4.6.25009.03, 64bit RyuJIT

	blueprint:
	name: Presence Light
	description: Turn on a light when presence is detected.
	domain: automation
	input:
	presence_entity:
	name: Presence Sensor
	description: Presence sensor device
	selector:
	entity:

	blueprint:
	name: Presence Light
	description: Turn on a light when presence is detected.
	domain: automation
	input:
	presence_entity:
	name: Presence Sensor
	description: Presence sensor device
	selector:
	entity: