Microsoft.CodeAnalysis.Analyzers.md

Microsoft.CodeAnalysis.Analyzers

RS1001: Missing diagnostic analyzer attribute

Item	Value
Category	MicrosoftCodeAnalysisCorrectness
Enabled	True
Severity	Warning
CodeFix	True

Rule description

Non-abstract sub-types of DiagnosticAnalyzer should be marked with DiagnosticAnalyzerAttribute(s). The argument to this attribute(s), if any, determine the supported languages for the analyzer. Analyzer types without this attribute will be ignored by the analysis engine.

RS1002: Missing kind argument when registering an analyzer action

Item	Value
Category	MicrosoftCodeAnalysisCorrectness
Enabled	True
Severity	Warning
CodeFix	False

Rule description

You must specify at least one syntax, symbol or operation kind when registering a syntax, symbol, or operation analyzer action respectively. Otherwise, the registered action will never be invoked during analysis.

RS1003: Unsupported SymbolKind argument when registering a symbol analyzer action

Item	Value
Category	MicrosoftCodeAnalysisCorrectness
Enabled	True
Severity	Warning
CodeFix	False

Rule description

SymbolKind '{0}' is not supported for symbol analyzer actions

RS1004: Recommend adding language support to diagnostic analyzer

Item	Value
Category	MicrosoftCodeAnalysisCorrectness
Enabled	True
Severity	Warning
CodeFix	False

Rule description

Diagnostic analyzer is marked as supporting only one language, but the analyzer assembly doesn't seem to refer to any language specific CodeAnalysis assemblies, and so is likely to work for more than one language. Consider adding an additional language argument to DiagnosticAnalyzerAttribute.

RS1005: ReportDiagnostic invoked with an unsupported DiagnosticDescriptor

Item	Value
Category	MicrosoftCodeAnalysisCorrectness
Enabled	True
Severity	Warning
CodeFix	False

Rule description

ReportDiagnostic should only be invoked with supported DiagnosticDescriptors that are returned from DiagnosticAnalyzer.SupportedDiagnostics property. Otherwise, the reported diagnostic will be filtered out by the analysis engine.

RS1006: Invalid type argument for DiagnosticAnalyzer's Register method

Item	Value
Category	MicrosoftCodeAnalysisCorrectness
Enabled	True
Severity	Warning
CodeFix	False

Rule description

DiagnosticAnalyzer's language-specific Register methods, such as RegisterSyntaxNodeAction, RegisterCodeBlockStartAction and RegisterCodeBlockEndAction, expect a language-specific 'SyntaxKind' type argument for it's 'TLanguageKindEnumName' type parameter. Otherwise, the registered analyzer action can never be invoked during analysis.

RS1007: Provide localizable arguments to diagnostic descriptor constructor

Item	Value
Category	MicrosoftCodeAnalysisLocalization
Enabled	False
Severity	Warning
CodeFix	False

Rule description

If your diagnostic analyzer and it's reported diagnostics need to be localizable, then the supported DiagnosticDescriptors used for constructing the diagnostics must also be localizable. If so, then localizable argument(s) must be provided for parameter 'title' (and optionally 'description') to the diagnostic descriptor constructor to ensure that the descriptor is localizable.

RS1008: Avoid storing per-compilation data into the fields of a diagnostic analyzer

Item	Value
Category	MicrosoftCodeAnalysisPerformance
Enabled	True
Severity	Warning
CodeFix	False

Rule description

Instance of a diagnostic analyzer might outlive the lifetime of compilation. Hence, storing per-compilation data, such as symbols, into the fields of a diagnostic analyzer might cause stale compilations to stay alive and cause memory leaks. Instead, you should store this data on a separate type instantiated in a compilation start action, registered using 'AnalysisContext.RegisterCompilationStartAction' API. An instance of this type will be created per-compilation and it won't outlive compilation's lifetime, hence avoiding memory leaks.

RS1009: Only internal implementations of this interface are allowed

Item	Value
Category	MicrosoftCodeAnalysisCompatibility
Enabled	True
Severity	Error
CodeFix	False

Rule description

The author of this interface did not intend to have third party implementations of this interface and reserves the right to change it. Implementing this interface could therefore result in a source or binary compatibility issue with a future version of this interface.

RS1010: Create code actions should have a unique EquivalenceKey for FixAll occurrences support

Item	Value
Category	Correctness
Enabled	True
Severity	Warning
CodeFix	False

Rule description

A CodeFixProvider that intends to support fix all occurrences must classify the registered code actions into equivalence classes by assigning it an explicit, non-null equivalence key which is unique for each kind of code action created by this fixer. This enables the FixAllProvider to fix all diagnostics in the required scope by applying code actions from this fixer that are in the equivalence class of the trigger code action.

RS1011: Use code actions that have a unique EquivalenceKey for FixAll occurrences support

Item	Value
Category	Correctness
Enabled	True
Severity	Warning
CodeFix	False

Rule description

A CodeFixProvider that intends to support fix all occurrences must classify the registered code actions into equivalence classes by assigning it an explicit, non-null equivalence key which is unique for each kind of code action created by this fixer. This enables the FixAllProvider to fix all diagnostics in the required scope by applying code actions from this fixer that are in the equivalence class of the trigger code action.

RS1012: Start action has no registered actions

Item	Value
Category	MicrosoftCodeAnalysisPerformance
Enabled	True
Severity	Warning
CodeFix	False

Rule description

An analyzer start action enables performing stateful analysis over a given code unit, such as a code block, compilation, etc. Careful design is necessary to achieve efficient analyzer execution without memory leaks. Use the following guidelines for writing such analyzers:
1. Define a new scope for the registered start action, possibly with a private nested type for analyzing each code unit.
2. If required, define and initialize state in the start action.
3. Register at least one non-end action that refers to this state in the start action. If no such action is necessary, consider replacing the start action with a non-start action. For example, a CodeBlockStartAction with no registered actions or only a registered CodeBlockEndAction should be replaced with a CodeBlockAction.
4. If required, register an end action to report diagnostics based on the final state.

RS1013: Start action has no registered non-end actions

Item	Value
Category	MicrosoftCodeAnalysisPerformance
Enabled	True
Severity	Warning
CodeFix	False

Rule description

An analyzer start action enables performing stateful analysis over a given code unit, such as a code block, compilation, etc. Careful design is necessary to achieve efficient analyzer execution without memory leaks. Use the following guidelines for writing such analyzers:
1. Define a new scope for the registered start action, possibly with a private nested type for analyzing each code unit.
2. If required, define and initialize state in the start action.
3. Register at least one non-end action that refers to this state in the start action. If no such action is necessary, consider replacing the start action with a non-start action. For example, a CodeBlockStartAction with no registered actions or only a registered CodeBlockEndAction should be replaced with a CodeBlockAction.
4. If required, register an end action to report diagnostics based on the final state.

RS1014: Do not ignore values returned by methods on immutable objects.

Item	Value
Category	MicrosoftCodeAnalysisCorrectness
Enabled	True
Severity	Warning
CodeFix	False

Rule description

Many objects exposed by Roslyn are immutable. The return value from a method invocation on these objects should not be ignored.

RS1015: Provide non-null 'helpLinkUri' value to diagnostic descriptor constructor

Item	Value
Category	MicrosoftCodeAnalysisDocumentation
Enabled	False
Severity	Warning
CodeFix	False

Rule description

The 'helpLinkUri' value is used to show information when this diagnostic in the error list. Every analyzer should have a helpLinkUri specified which points to a help page that does not change over time.

RS1016: Code fix providers should provide FixAll support

Item	Value
Category	Correctness
Enabled	True
Severity	Warning
CodeFix	True

Rule description

A CodeFixProvider should provide FixAll support to enable users to fix multiple instances of the underlying diagnostic with a single code fix. See documenation at https://github.com/dotnet/roslyn/blob/master/docs/analyzers/FixAllProvider.md for further details.

RS1017: DiagnosticId for analyzers must be a non-null constant

Item	Value
Category	MicrosoftCodeAnalysisDesign
Enabled	True
Severity	Warning
CodeFix	False

Rule description

DiagnosticId for analyzers must be a non-null constant.

RS1018: DiagnosticId for analyzers must be in specified format

Item	Value
Category	MicrosoftCodeAnalysisDesign
Enabled	True
Severity	Warning
CodeFix	False

Rule description

DiagnosticId for analyzers must be in specified format.

RS1019: DiagnosticId must be unique across analyzers

Item	Value
Category	MicrosoftCodeAnalysisDesign
Enabled	True
Severity	Warning
CodeFix	False

Rule description

DiagnosticId must be unique across analyzers.

RS1020: Category for analyzers must be from the specified values

Item	Value
Category	MicrosoftCodeAnalysisDesign
Enabled	False
Severity	Warning
CodeFix	False

Rule description

Category for analyzers must be from the specified values.

RS1021: Invalid entry in analyzer category and diagnostic ID range specification file

Item	Value
Category	MicrosoftCodeAnalysisDesign
Enabled	True
Severity	Warning
CodeFix	False

Rule description

Invalid entry in analyzer category and diagnostic ID range specification file.

RS1022: Do not use types from Workspaces assembly in an analyzer

Item	Value
Category	MicrosoftCodeAnalysisCorrectness
Enabled	True
Severity	Warning
CodeFix	False

Rule description

Diagnostic analyzer types should not use types from Workspaces assemblies. Workspaces assemblies are only available when the analyzer executes in Visual Studio IDE live analysis, but are not available during command line build. Referencing types from Workspaces assemblies will lead to runtime exception during analyzer execution in command line build.

RS1023: Upgrade MSBuildWorkspace

Item	Value
Category	Library
Enabled	True
Severity	Warning
CodeFix	False

Rule description

MSBuildWorkspace has moved to the Microsoft.CodeAnalysis.Workspaces.MSBuild NuGet package and there are breaking API changes.

RS1024: Compare symbols correctly

Item	Value
Category	MicrosoftCodeAnalysisCorrectness
Enabled	True
Severity	Warning
CodeFix	True

Rule description

Symbols should be compared for equality, not identity.

RS1025: Configure generated code analysis

Item	Value
Category	MicrosoftCodeAnalysisCorrectness
Enabled	True
Severity	Warning
CodeFix	True

Rule description

Configure generated code analysis

RS1026: Enable concurrent execution

Item	Value
Category	MicrosoftCodeAnalysisCorrectness
Enabled	True
Severity	Warning
CodeFix	True

Rule description

Enable concurrent execution

RS1027: Types marked with DiagnosticAnalyzerAttribute(s) should inherit from DiagnosticAnalyzer

Item	Value
Category	MicrosoftCodeAnalysisCorrectness
Enabled	True
Severity	Warning
CodeFix	False

Rule description

Inherit type '{0}' from DiagnosticAnalyzer or remove the DiagnosticAnalyzerAttribute(s)

RS1028: Provide non-null 'customTags' value to diagnostic descriptor constructor

Item	Value
Category	MicrosoftCodeAnalysisDocumentation
Enabled	False
Severity	Warning
CodeFix	False

Rule description

The 'customTags' value is used as a way to enable specific actions and filters on diagnostic descriptors based on the specific values of the tags. Every Roslyn analyzer should have at least one tag from the 'WellKnownDiagnosticTags' class.

RS1029: Do not use reserved diagnostic IDs

Item	Value
Category	MicrosoftCodeAnalysisDesign
Enabled	True
Severity	Warning
CodeFix	False

Rule description

DiagnosticId for analyzers should not use reserved IDs.

RS1030: Do not invoke Compilation.GetSemanticModel() method within a diagnostic analyzer

Item	Value
Category	MicrosoftCodeAnalysisCorrectness
Enabled	True
Severity	Warning
CodeFix	False

Rule description

'GetSemanticModel' is an expensive method to invoke within a diagnostic analyzer because it creates a completely new semantic model, which does not share compilation data with the compiler or other analyzers. This incurs an additional performance cost during semantic analysis. Instead, consider registering a different analyzer action which allows used of a shared 'SemanticModel', such as 'RegisterOperationAction', 'RegisterSyntaxNodeAction', or 'RegisterSemanticModelAction'.

RS1031: Define diagnostic title correctly

Item	Value
Category	MicrosoftCodeAnalysisDesign
Enabled	True
Severity	Warning
CodeFix	True

Rule description

The diagnostic title should not contain a period or any line return character

RS1032: Define diagnostic message correctly

Item	Value
Category	MicrosoftCodeAnalysisDesign
Enabled	True
Severity	Warning
CodeFix	True

Rule description

The diagnostic message should not contain any line return character and should either be a single sentence without a trailing period or a multi-sentences with a trailing period

RS1033: Define diagnostic description correctly

Item	Value
Category	MicrosoftCodeAnalysisDesign
Enabled	True
Severity	Warning
CodeFix	True

Rule description

The diagnostic description should be one or multiple sentences ending with a punctuation sign

RS2000: Add analyzer diagnostic IDs to analyzer release.

Item	Value
Category	MicrosoftCodeAnalysisReleaseTracking
Enabled	True
Severity	Warning
CodeFix	True

Rule description

All supported analyzer diagnostic IDs should be part of an analyzer release.

RS2001: Ensure up-to-date entry for analyzer diagnostic IDs are added to analyzer release.

Item	Value
Category	MicrosoftCodeAnalysisReleaseTracking
Enabled	True
Severity	Warning
CodeFix	True

Rule description

Ensure up-to-date entry for analyzer diagnostic IDs are added to analyzer release.

RS2002: Do not add removed analyzer diagnostic IDs to unshipped analyzer release.

Item	Value
Category	MicrosoftCodeAnalysisReleaseTracking
Enabled	True
Severity	Warning
CodeFix	False

Rule description

Entries for analyzer diagnostic IDs that are no longer reported and never shipped can be removed from unshipped analyzer release.

RS2003: Shipped diagnostic IDs that are no longer reported should have an entry in the 'Removed Rules' table in unshipped file.

Item	Value
Category	MicrosoftCodeAnalysisReleaseTracking
Enabled	True
Severity	Warning
CodeFix	False

Rule description

Shipped diagnostic IDs that are no longer reported should have an entry in the 'Removed Rules' table in unshipped file.

RS2004: Diagnostic IDs marked as removed in analyzer release file should not be reported by analyzers.

Item	Value
Category	MicrosoftCodeAnalysisReleaseTracking
Enabled	True
Severity	Warning
CodeFix	False

Rule description

Diagnostic IDs marked as removed in analyzer release file should not be reported by analyzers.

RS2005: Remove duplicate entries for diagnostic ID in the same analyzer release.

Item	Value
Category	MicrosoftCodeAnalysisReleaseTracking
Enabled	True
Severity	Warning
CodeFix	False

Rule description

Remove duplicate entries for diagnostic ID in the same analyzer release.

RS2006: Remove duplicate entries for diagnostic ID between analyzer releases.

Item	Value
Category	MicrosoftCodeAnalysisReleaseTracking
Enabled	True
Severity	Warning
CodeFix	False

Rule description

Remove duplicate entries for diagnostic ID between analyzer releases.

RS2007: Invalid entry in analyzer release file.

Item	Value
Category	MicrosoftCodeAnalysisReleaseTracking
Enabled	True
Severity	Warning
CodeFix	False

Rule description

Invalid entry in analyzer release file.

RS2008: Enable analyzer release tracking

Item	Value
Category	MicrosoftCodeAnalysisReleaseTracking
Enabled	True
Severity	Warning
CodeFix	True

Rule description

Enabling release tracking for analyzer packages helps in tracking and documenting the analyzer diagnostics that ship and/or change with each analyzer release. See details at https://github.com/dotnet/roslyn-analyzers/blob/master/src/Microsoft.CodeAnalysis.Analyzers/ReleaseTrackingAnalyzers.Help.md.