index.md

Overview of implemented NUnit diagnostics and code fixes

In the tables below we use the following symbols:

• 🔍 - whether the diagnostic is enabled by default or not
• 📝 - the severity of the diagnostic
• 💡 - whether the diagnostic has an associated code fix or not

The severity of a diagnostic can the one of the following (in increasing severity):

• 💭 - indicates a severity of Hidden
• ℹ️ - indicates a severity of Info
• ⚠️ - indicates a severity of Warning
• ❗ - indicates a severity of Error

Structure Rules (NUnit1001 - )

Rules which enforce structural requirements on the test code.

Id	Title	🔍	📝	💡
NUnit1001	The individual arguments provided by a TestCaseAttribute must match the type of the corresponding parameter of the method	✅	❗	❌
NUnit1002	The TestCaseSource should use nameof operator to specify target	✅	⚠️	✅
NUnit1003	The TestCaseAttribute provided too few arguments	✅	❗	❌
NUnit1004	The TestCaseAttribute provided too many arguments	✅	❗	❌
NUnit1005	The type of the value specified via ExpectedResult must match the return type of the method	✅	❗	❌
NUnit1006	ExpectedResult must not be specified when the method returns void	✅	❗	❌
NUnit1007	The method has non-void return type, but no result is expected in ExpectedResult	✅	❗	❌
NUnit1008	Specifying ParallelScope.Self on assembly level has no effect	✅	⚠️	❌
NUnit1009	One may not specify ParallelScope.Children on a non-parameterized test method	✅	❗	❌
NUnit1010	One may not specify ParallelScope.Fixtures on a test method	✅	❗	❌
NUnit1011	The TestCaseSource argument does not specify an existing member	✅	❗	❌
NUnit1012	The async test method must have a non-void return type	✅	❗	❌
NUnit1013	The async test method must have a non-generic Task return type when no result is expected	✅	❗	❌
NUnit1014	The async test method must have a Task<T> return type when a result is expected	✅	❗	❌
NUnit1015	The source type does not implement I(Async)Enumerable	✅	❗	❌
NUnit1016	The source type does not have a default constructor	✅	❗	❌
NUnit1017	The specified source is not static	✅	❗	❌
NUnit1018	The number of parameters provided by the TestCaseSource does not match the number of parameters in the target method	✅	❗	❌
NUnit1019	The source specified by the TestCaseSource does not return an I(Async)Enumerable or a type that implements I(Async)Enumerable	✅	❗	❌
NUnit1020	The TestCaseSource provides parameters to a source - field or property - that expects no parameters	✅	❗	❌
NUnit1021	The ValueSource should use nameof operator to specify target	✅	⚠️	✅
NUnit1022	The specified source is not static	✅	❗	❌
NUnit1023	The target method expects parameters which cannot be supplied by the ValueSource	✅	❗	❌
NUnit1024	The source specified by the ValueSource does not return an I(Async)Enumerable or a type that implements I(Async)Enumerable	✅	❗	❌
NUnit1025	The ValueSource argument does not specify an existing member	✅	❗	❌
NUnit1026	The test or setup/teardown method is not public	✅	❗	✅
NUnit1027	The test method has parameters, but no arguments are supplied by attributes	✅	❗	❌
NUnit1028	The non-test method is public	✅	ℹ️	✅
NUnit1029	The number of parameters provided by the TestCaseSource does not match the number of parameters in the Test method	✅	❗	❌
NUnit1030	The type of parameter provided by the TestCaseSource does not match the type of the parameter in the Test method	✅	❗	❌
NUnit1031	The individual arguments provided by a ValuesAttribute must match the type of the corresponding parameter of the method	✅	❗	❌
NUnit1032	An IDisposable field/property should be Disposed in a TearDown method	✅	❗	❌
NUnit1033	The Write methods on TestContext will be marked as Obsolete and eventually removed	✅	⚠️	✅

Assertion Rules (NUnit2001 - )

Rules which improve assertions in the test code.

Id	Title	🔍	📝	💡
NUnit2001	Consider using Assert.That(expr, Is.False) instead of ClassicAssert.False(expr)	✅	ℹ️	✅
NUnit2002	Consider using Assert.That(expr, Is.False) instead of ClassicAssert.IsFalse(expr)	✅	ℹ️	✅
NUnit2003	Consider using Assert.That(expr, Is.True) instead of ClassicAssert.IsTrue(expr)	✅	ℹ️	✅
NUnit2004	Consider using Assert.That(expr, Is.True) instead of ClassicAssert.True(expr)	✅	ℹ️	✅
NUnit2005	Consider using Assert.That(actual, Is.EqualTo(expected)) instead of ClassicAssert.AreEqual(expected, actual)	✅	⚠️	✅
NUnit2006	Consider using Assert.That(actual, Is.Not.EqualTo(expected)) instead of ClassicAssert.AreNotEqual(expected, actual)	✅	⚠️	✅
NUnit2007	The actual value should not be a constant	✅	⚠️	✅
NUnit2008	Incorrect IgnoreCase usage	✅	⚠️	❌
NUnit2009	The same value has been provided as both the actual and the expected argument	✅	⚠️	❌
NUnit2010	Use EqualConstraint for better assertion messages in case of failure	✅	ℹ️	✅
NUnit2011	Use ContainsConstraint for better assertion messages in case of failure	✅	ℹ️	✅
NUnit2012	Use StartsWithConstraint for better assertion messages in case of failure	✅	ℹ️	✅
NUnit2013	Use EndsWithConstraint for better assertion messages in case of failure	✅	ℹ️	✅
NUnit2014	Use SomeItemsConstraint for better assertion messages in case of failure	✅	ℹ️	✅
NUnit2015	Consider using Assert.That(actual, Is.SameAs(expected)) instead of ClassicAssert.AreSame(expected, actual)	✅	⚠️	✅
NUnit2016	Consider using Assert.That(expr, Is.Null) instead of ClassicAssert.Null(expr)	✅	ℹ️	✅
NUnit2017	Consider using Assert.That(expr, Is.Null) instead of ClassicAssert.IsNull(expr)	✅	ℹ️	✅
NUnit2018	Consider using Assert.That(expr, Is.Not.Null) instead of ClassicAssert.NotNull(expr)	✅	ℹ️	✅
NUnit2019	Consider using Assert.That(expr, Is.Not.Null) instead of ClassicAssert.IsNotNull(expr)	✅	ℹ️	✅
NUnit2020	Incompatible types for SameAs constraint	✅	❗	❌
NUnit2021	Incompatible types for EqualTo constraint	✅	❗	❌
NUnit2022	Missing property required for constraint	✅	❗	✅
NUnit2023	Invalid NullConstraint usage	✅	❗	❌
NUnit2024	Wrong actual type used with String Constraint	✅	❗	❌
NUnit2025	Wrong actual type used with ContainsConstraint	❌	💭	❌
NUnit2026	Wrong actual type used with the SomeItemsConstraint with EqualConstraint	✅	❗	❌
NUnit2027	Consider using Assert.That(actual, Is.GreaterThan(expected)) instead of ClassicAssert.Greater(actual, expected)	✅	ℹ️	✅
NUnit2028	Consider using Assert.That(actual, Is.GreaterThanOrEqualTo(expected)) instead of ClassicAssert.GreaterOrEqual(actual, expected)	✅	ℹ️	✅
NUnit2029	Consider using Assert.That(actual, Is.LessThan(expected)) instead of ClassicAssert.Less(actual, expected)	✅	ℹ️	✅
NUnit2030	Consider using Assert.That(actual, Is.LessThanOrEqualTo(expected)) instead of ClassicAssert.LessOrEqual(actual, expected)	✅	ℹ️	✅
NUnit2031	Consider using Assert.That(actual, Is.Not.SameAs(expected)) instead of ClassicAssert.AreNotSame(expected, actual)	✅	⚠️	✅
NUnit2032	Consider using Assert.That(expr, Is.Zero) instead of ClassicAssert.Zero(expr)	✅	ℹ️	✅
NUnit2033	Consider using Assert.That(expr, Is.Not.Zero) instead of ClassicAssert.NotZero(expr)	✅	ℹ️	✅
NUnit2034	Consider using Assert.That(expr, Is.NaN) instead of ClassicAssert.IsNaN(expr)	✅	ℹ️	✅
NUnit2035	Consider using Assert.That(collection, Is.Empty) instead of ClassicAssert.IsEmpty(collection)	✅	ℹ️	✅
NUnit2036	Consider using Assert.That(collection, Is.Not.Empty) instead of ClassicAssert.IsNotEmpty(collection)	✅	ℹ️	✅
NUnit2037	Consider using Assert.That(collection, Does.Contain(instance)) instead of ClassicAssert.Contains(instance, collection)	✅	ℹ️	✅
NUnit2038	Consider using Assert.That(actual, Is.InstanceOf(expected)) instead of ClassicAssert.IsInstanceOf(expected, actual)	✅	ℹ️	✅
NUnit2039	Consider using Assert.That(actual, Is.Not.InstanceOf(expected)) instead of ClassicAssert.IsNotInstanceOf(expected, actual)	✅	ℹ️	✅
NUnit2040	Non-reference types for SameAs constraint	✅	❗	✅
NUnit2041	Incompatible types for comparison constraint	✅	❗	❌
NUnit2042	Comparison constraint on object	✅	ℹ️	❌
NUnit2043	Use ComparisonConstraint for better assertion messages in case of failure	✅	ℹ️	✅
NUnit2044	Non-delegate actual parameter	✅	❗	✅
NUnit2045	Use Assert.Multiple	✅	ℹ️	✅
NUnit2046	Use CollectionConstraint for better assertion messages in case of failure	✅	ℹ️	✅
NUnit2047	Incompatible types for Within constraint	✅	⚠️	✅
NUnit2048	Consider using Assert.That(...) instead of StringAssert(...)	✅	⚠️	✅
NUnit2049	Consider using Assert.That(...) instead of CollectionAssert(...)	✅	⚠️	✅
NUnit2050	NUnit 4 no longer supports string.Format specification	✅	❗	✅

Suppressor Rules (NUnit3001 - )

Rules which suppress compiler errors based on context. Note that these rules are only available in the .NET Standard 2.0 builds (version 3.0.0 and above) which require Visual Studio 2019 (version 16.3) or newer.

Id	Title	🔍	📝	💡
NUnit3001	Expression was checked in an ClassicAssert.NotNull, ClassicAssert.IsNotNull or Assert.That call	✅	ℹ️	❌
NUnit3002	Field/Property is initialized in SetUp or OneTimeSetUp method	✅	ℹ️	❌
NUnit3003	Class is an NUnit TestFixture and is instantiated using reflection	✅	ℹ️	❌
NUnit3004	Field should be Disposed in TearDown or OneTimeTearDown method	✅	ℹ️	❌

Style Rules (NUnit4001 - )

Rules which help you write concise and readable NUnit test code.

Id	Title	🔍	📝	💡
NUnit4001	Simplify the Values attribute	✅	ℹ️	❌