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GCI0043InfoObservability and Error Handling

Nullability and Type Safety

Detects null-forgiving operator (!) overuse, pragma warning disables for nullable, and unchecked as-casts that bypass the type system.

Why this rule exists

Every ! and #pragma warning disable nullable is a promise to the compiler that the developer knows better. When that promise is wrong, you get a NullReferenceException with no help from the type system.

Code example

Triggers the rule
+ var name = user!.Profile!.DisplayName!;
Passes the rule
+ var name = user?.Profile?.DisplayName
+     ?? throw new InvalidOperationException("Profile missing");

Configuration

Disable or adjust the severity of this rule in .gauntletci.json:

{
  "rules": {
    "GCI0043": { "enabled": true, "severity": "Info" }
  }
}

See Configuration for the full schema.

Related rules

GCI0006Warn

Edge Case Handling

Detects potential null dereferences and missing validation in added code.

GCI0007Block

Error Handling Integrity

Detects swallowed exceptions (empty catch blocks) and exception handling patterns that hide failures from callers and operators.

Real-world evidence

JamesNK/Newtonsoft.JsonPR #1950

Nullable Migration in Newtonsoft.Json

A 169-file nullable reference type migration changed public annotations and fixed null-parent behavior.

Implemented in src/GauntletCI.Core/Rules/Implementations/GCI0043_*.cs.

About the author

Eric Cogen -- Founder, GauntletCI

Twenty years as a senior technical consultant building and modernizing enterprise platforms across .NET, AWS, serverless, microservices, and AI-driven systems.

@EricCogen/GauntletCI on GitHub/More about Eric