MSTEST0017: Assertion arguments should be passed in the correct order

Property	Value
Rule ID	MSTEST0017
Title	Assertion arguments should be passed in the correct order
Category	Usage
Fix is breaking or non-breaking	Non-breaking
Enabled by default	Yes
Default severity	Info
Introduced in version	3.4.0
Is there a code fix	Yes

Cause

This rule raises an issue when calls to Assert.AreEqual, Assert.AreNotEqual, Assert.AreSame or Assert.AreNotSame are following one or multiple of the patterns below:

• actual argument is a constant or literal value
• actual argument variable starts with expected, _expected or Expected
• expected or notExpected argument variable starts with actual
• actual is not a local variable

Rule description

MSTest Assert.AreEqual, Assert.AreNotEqual, Assert.AreSame and Assert.AreNotSame expect the first argument to be the expected/unexpected value and the second argument to be the actual value.

Having the expected value and the actual value in the wrong order will not alter the outcome of the test (succeeds/fails when it should), but the assertion failure will contain misleading information.

How to fix violations

Ensure that that actual and expected/notExpected arguments are passed in the correct order.

When to suppress warnings

Do not suppress a warning from this rule as it would result to misleading output.

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 MSTEST0017
// The code that's violating the rule is on this line.
#pragma warning restore MSTEST0017

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

[*.{cs,vb}]
dotnet_diagnostic.MSTEST0017.severity = none

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