SharpSource

Demonstration of an analyzer which removes unnecessary IEnumerable materializations

Quickstart

Install it through the command line:

Install-Package SharpSource

or add a reference yourself:

<ItemGroup>
    <PackageReference Include="SharpSource" Version="1.31.1" PrivateAssets="All" />
</ItemGroup>

If you would like to install it as an extension instead, download it from the marketplace.

This repo houses a collection of analyzers that aim to make some language features and framework types easier to work with. It does this by highlighting when you might be using something incorrectly in a way that would result in suboptimal performance, runtime exceptions or general unintended behaviour.

In other words, this repo only contains analyzers for patterns that have a concrete potential to turn into a defect ticket. It is not intended to help with general housekeeping tasks like formatting your code or providing productivity helpers.

Interested in contributing? Take a look at the guidelines!

Detailed explanations of each analyzer can be found in the documentation: https://github.com/Vannevelj/SharpSource/tree/master/docs

Code	Name	Description
SS001	AsyncMethodWithVoidReturnType	Async methods should return `Task` instead of `void` to allow proper exception handling and awaiting.
SS002	DateTimeNow	Use `DateTime.UtcNow` instead of `DateTime.Now` to avoid timezone-related issues.
SS003	DivideIntegerByInteger	Dividing integers results in integer division; cast to floating-point if a decimal result is expected.
SS004	ElementaryMethodsOfTypeInCollectionNotOverridden	Types used as collection keys should override `Equals` and `GetHashCode`.
SS005	EqualsAndGetHashcodeNotImplementedTogether	`Equals` and `GetHashCode` should always be overridden together.
SS006	ThrowNull	Throwing `null` will result in a `NullReferenceException` at runtime.
SS007	FlagsEnumValuesAreNotPowersOfTwo	Flags enum values should be powers of two to allow proper bitwise operations.
SS008	GetHashCodeRefersToMutableMember	`GetHashCode` should not reference mutable members as this breaks hash-based collections.
SS009	LoopedRandomInstantiation	Creating `Random` instances in a loop can produce identical sequences; reuse a single instance.
SS010	NewGuid	Use `Guid.NewGuid()` instead of `new Guid()` to generate a unique identifier.
SS011	OnPropertyChangedWithoutNameofOperator	Use `nameof()` instead of hardcoded property name strings in `OnPropertyChanged`.
SS012	RecursiveOperatorOverload	Operator overloads calling themselves will cause infinite recursion.
SS013	RethrowExceptionWithoutLosingStacktrace	Use `throw;` instead of `throw ex;` to preserve the original stack trace.
SS014	StringDotFormatWithDifferentAmountOfArguments	The number of format placeholders should match the number of arguments.
SS015	StringPlaceholdersInWrongOrder	Format placeholders should be in sequential order starting from `{0}`.
SS017	StructWithoutElementaryMethodsOverridden	Structs should override `Equals`, `GetHashCode`, and implement `IEquatable<T>` for performance.
SS018	SwitchDoesNotHandleAllEnumOptions	Switch statements on enums should handle all possible values.
SS019	SwitchIsMissingDefaultLabel	Switch statements should have a default case to handle unexpected values.
SS020	TestMethodWithoutPublicModifier	Test methods must be public to be discovered by test runners.
SS021	TestMethodWithoutTestAttribute	Methods that look like tests should have a test attribute to be executed.
SS022	ExceptionThrownFromImplicitOperator	Implicit operators should not throw exceptions as they are called invisibly.
SS023	ExceptionThrownFromPropertyGetter	Property getters should not throw exceptions; consider using a method instead.
SS024	ExceptionThrownFromStaticConstructor	Exceptions in static constructors cause `TypeInitializationException` and make the type unusable.
SS025	ExceptionThrownFromFinallyBlock	Exceptions in finally blocks can mask original exceptions from try blocks.
SS026	ExceptionThrownFromEqualityOperator	Equality operators should not throw exceptions; return `false` for invalid comparisons.
SS027	ExceptionThrownFromDispose	`Dispose` methods should not throw exceptions as they may be called during exception unwinding.
SS028	ExceptionThrownFromFinalizer	Finalizers should not throw exceptions as this will terminate the process.
SS029	ExceptionThrownFromGetHashCode	`GetHashCode` should not throw exceptions; return a consistent value instead.
SS030	ExceptionThrownFromEquals	`Equals` should not throw exceptions; return `false` for invalid comparisons.
SS032	ThreadSleepInAsyncMethod	Use `await Task.Delay()` instead of `Thread.Sleep()` in async methods to avoid blocking threads.
SS033	AsyncOverloadsAvailable	Use async overloads when available to avoid blocking the calling thread.
SS034	AccessingTaskResultWithoutAwait	Accessing `Task.Result` without awaiting can cause deadlocks; use `await` instead.
SS035	SynchronousTaskWait	Using `.Wait()` or `.Result` on tasks can cause deadlocks; use `await` instead.
SS036	ExplicitEnumValues	Enum members should have explicit values when the values are persisted or serialized.
SS037	HttpClientInstantiatedDirectly	Use `IHttpClientFactory` instead of creating `HttpClient` directly to avoid socket exhaustion.
SS038	HttpContextStoredInField	`HttpContext` should not be stored in fields as it's request-scoped and may be invalid later.
SS039	EnumWithoutDefaultValue	Enums should have a member with value `0` to represent the default state.
SS040	UnusedResultOnImmutableObject	Methods on immutable types return new instances; the result should not be discarded.
SS041	UnnecessaryEnumerableMaterialization	Avoid materializing enumerables (e.g., `ToList()`) when the result is immediately enumerated.
SS042	InstanceFieldWithThreadStatic	`[ThreadStatic]` only works on static fields; it has no effect on instance fields.
SS043	MultipleFromBodyParameters	Web API actions can only have one `[FromBody]` parameter.
SS044	AttributeMustSpecifyAttributeUsage	Custom attributes should specify `[AttributeUsage]` to define valid targets.
SS045	StaticInitializerAccessedBeforeInitialization	Static field initializers may access fields before they are initialized.
SS046	UnboundedStackalloc	`stackalloc` without a size limit can cause stack overflow; consider using a maximum size.
SS047	LinqTraversalBeforeFilter	Apply `Where` filters before `Select` projections to avoid unnecessary work.
SS048	LockingOnDiscouragedObject	Avoid locking on `this`, `typeof()`, or strings as these can cause deadlocks.
SS049	ComparingStringsWithoutStringComparison	String comparisons should specify a `StringComparison` to ensure correct behavior.
SS050	ParameterAssignedInConstructor	Assigning to a parameter instead of a field in a constructor is likely a mistake.
SS051	LockingOnMutableReference	Locking on a field that can be reassigned may cause race conditions.
SS052	ThreadStaticWithInitializer	`[ThreadStatic]` field initializers only run once; use lazy initialization instead.
SS053	PointlessCollectionToString	Calling `ToString()` on collections returns the type name, not the contents.
SS054	NewtonsoftMixedWithSystemTextJson	Mixing Newtonsoft.Json and System.Text.Json attributes causes serialization issues.
SS055	MultipleOrderByCalls	Multiple `OrderBy` calls override each other; use `ThenBy` for secondary sorting.
SS056	FormReadSynchronously	Reading form data synchronously blocks threads; use async methods instead.
SS057	CollectionManipulatedDuringTraversal	Modifying a collection while iterating over it causes `InvalidOperationException`.
SS058	StringConcatenatedInLoop	Use `StringBuilder` instead of string concatenation in loops for better performance.
SS059	DisposeAsyncDisposable	Types implementing `IAsyncDisposable` should be disposed with `await using`.
SS060	ConcurrentDictionaryEmptyCheck	Use `IsEmpty` instead of `Count == 0` on `ConcurrentDictionary` for thread safety.
SS061	ImmutableCollectionCreatedIncorrectly	Use builder methods or `Create()` instead of constructors for immutable collections.
SS062	ActivityWasNotStopped	`Activity` instances must be stopped to ensure telemetry data is recorded.
SS063	ValueTaskAwaitedMultipleTimes	`ValueTask` can only be awaited once; store the result or convert to `Task` if needed.
SS064	UnnecessaryToStringOnSpan	Avoid calling `ToString()` on spans when an overload accepting spans directly is available.
SS065	LoggerMessageAttribute	Use the `[LoggerMessage]` attribute for high-performance logging instead of extension methods.

Configuration

Is a particular rule not to your liking? There are many ways to adjust their severity and even disable them altogether. For an overview of some of the options, check out this document.

Jeroen Vannevel

Quickstart

Configuration