Moq1201.md

Moq1201: Setup of async methods should use .ReturnsAsync instance instead of .Result

Item	Value
Enabled	True
Severity	Error
CodeFix	False

---

Moq now supports the .ReturnsAsync() method to support mocking async methods. Use it instead of returning .Result, which can cause issues.

Examples of patterns that are flagged by this analyzer

class AsyncClient
{
    virtual Task<string> GetAsync() => Task.FromResult(string.Empty);
}

var mock = new Mock<AsyncClient>()
    .Setup(c => c.GetAsync().Result); // Moq1201: Setup of async methods should use .ReturnsAsync instance instead of .Result

Solution

class AsyncClient
{
    virtual Task<string> GetAsync() => Task.FromResult(string.Empty);
}

var mock = new Mock<AsyncClient>()
    .Setup(c => c.GetAsync()).ReturnsAsync(string.Empty);

Suppress a warning

If you just want to suppress a single violation, add preprocessor directives to your source file to disable and then re-enable the rule.

#pragma warning disable Moq1201
var mock = new Mock<AsyncClient>()
    .Setup(c => c.GetAsync().Result); // Moq1201: Setup of async methods should use .ReturnsAsync instance instead of .Result
#pragma warning restore Moq1201

To disable the rule for a file, folder, or project, set its severity to none in the configuration file.

[*.{cs,vb}]
dotnet_diagnostic.Moq1201.severity = none

For more information, see How to suppress code analysis warnings.