Summary
The issue of async tests never finishing after upgrading to MSTest 4.0.2 is a critical problem that can hinder the testing process. The symptoms include tests that hang indefinitely, never reaching completion. This problem arose after upgrading from MSTest 1.4.0 to MSTest 4.0.2, with the test framework and test adapter also updated to version 4.0.2.
Root Cause
The root cause of this issue is related to the changes in how MSTest handles asynchronous tests. Key factors include:
- Incompatible asynchronous test handling between different versions of MSTest
- Missing or incorrect configuration of the test framework and adapter
- Changes in the test execution environment, such as the use of Rider as the test runner
Why This Happens in Real Systems
This issue occurs in real systems due to:
- Version mismatches between test frameworks and adapters
- Incorrect test configuration, such as missing or incorrect PackageReferences in the .csproj file
- Environmental factors, such as the use of specific test runners or IDEs
Real-World Impact
The real-world impact of this issue includes:
- Delayed testing and deployment due to hanging tests
- Increased debugging time to identify and resolve the issue
- Potential for missed defects due to incomplete testing
Example or Code
[TestMethod]
public async Task Test1()
{
await Task.Delay(1);
Console.WriteLine("Test1");
}How Senior Engineers Fix It
Senior engineers fix this issue by:
- Verifying compatible versions of MSTest, test framework, and test adapter
- Configuring the test framework and adapter correctly, including ensuring the correct PackageReferences in the .csproj file
- Using the correct test runner and environment, such as Visual Studio or dotnet cli
Why Juniors Miss It
Junior engineers may miss this issue due to:
- Lack of experience with MSTest and asynchronous testing
- Insufficient knowledge of test framework and adapter configuration
- Inadequate debugging skills to identify and resolve the root cause of the issue