dotnet/Documentation/compatibility/code-contracts-and-string-isnullorempty-compiler-warning.md

Contract.Invariant or Contract.Requires do not consider String.IsNullOrEmpty to be pure

Scope

Minor

Version Introduced

4.6.1

Source Analyzer Status

Investigating

Change Description

For apps that target the .NET Framework 4.6.1, if the invariant contract for xref:System.Diagnostics.Contracts.Contract.Invariant%2A?displayProperty=nameWithType or the precondition contract for xref:System.Diagnostics.Contracts.Contract.Requires%2A?displayProperty=nameWithType) calls the xref:System.String.IsNullOrEmpty%2A?displayProperty=nameWithType method, the rewriter emits compiler warning CC1036: "Detected call to method 'System.String.IsNullOrWhteSpace(System.String)' without [Pure] in method." This is a compiler warning rather than a compiler error.

• Quirked
• Build-time break

Recommended Action

This behavior was addressed in GitHub Issue #339. To eliminate this warning, you can download and compile an updated version of the source code for the Code Contracts tool from GitHub. Download information is found at the bottom of the page.

Affected APIs

• M:System.Diagnostics.Contracts.Contract.Invariant(System.Boolean)
• M:System.Diagnostics.Contracts.Contract.Requires(System.Boolean)

Category

Tools