GauntletCI logoGauntletCI
All rules
GCI0055BlockBehavior and Contracts

Method Signature Change Risk

Detects breaking method signature changes: removed parameters, new required parameters without defaults, or return type changes in public methods.

Why this rule exists

Public method signatures are contracts. Removing a parameter, adding a required one, or changing the return type breaks every caller. These changes demand deprecation cycles, not silent breaking changes.

Code example

Triggers the rule
- public Task<User> GetUser(int id) { }
+ public Task<User> GetUser(Guid id) { }
+ // OR
- public void ProcessOrder(Order order) { }
+ public void ProcessOrder(Order order, ProcessOptions options) { }  // no default
Passes the rule
  [Obsolete("Use GetUserAsync(Guid)")]
  public Task<User> GetUser(int id) => GetUserAsync(new Guid(id.ToString()));
+ public Task<User> GetUserAsync(Guid id) { }
+ // OR
+ public void ProcessOrder(Order order, ProcessOptions options = null) { }  // default provided

Configuration

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

{
  "rules": {
    "GCI0055": { "enabled": true, "severity": "Block" }
  }
}

See Configuration for the full schema.

Related rules

GCI0004Block

Breaking Change Risk

Detects removed public APIs and changed public method signatures that may break callers.

GCI0046Info

Pattern Consistency Deviation

Detects mixed sync/async naming conventions and service locator anti-patterns introduced inconsistently within the same file.

Implemented in src/GauntletCI.Core/Rules/Implementations/GCI0055_*.cs.

About the author

Eric Cogen -- Founder, GauntletCI

Twenty years in .NET production. Most of those years, the bugs that hurt me were not the ones tests caught. They were the assumptions I did not know I was making: a removed guard clause, a renamed method that still did the old thing, a catch {} that turned a page into a silent dashboard lie. GauntletCI is the checklist I wish I had run before every commit. It runs the rules I learned the hard way, so you do not have to.

@EricCogen/GauntletCI on GitHub/More about Eric