Pure Context Mutation
Detects assignment operators inside property getter blocks or methods decorated with [Pure], indicating unexpected side effects.
Why this rule exists
Property getters and [Pure] methods are called by debuggers, serializers, and LINQ providers. Hidden side effects in them produce non-deterministic bugs that reproduce only under specific tooling.
Code example
+ public int Count
+ {
+ get { _accessCount++; return _items.Count; }
+ }+ public int Count => _items.Count;
+ public void RecordAccess() => _accessCount++;Configuration
Disable or adjust the severity of this rule in .gauntletci.json:
{
"rules": {
"GCI0036": { "enabled": true, "severity": "Block" }
}
}See Configuration for the full schema.
Related rules
Behavioral Change Detection
Detects removed logic lines and changed method signatures that alter runtime behavior without corresponding test updates.
Concurrency and State Risk
Detects async void methods, blocking async calls (.Result, .Wait()), static mutable state, and patterns that introduce deadlock risk.
Discussed in
Why Code Review Misses Bugs
Code review catches style and obvious logic errors. It routinely misses behavioral drift, contract changes, and implicit assumptions.
A Formal Framework for Behavioral Change Risk
A structured taxonomy for behavioral, contract, concurrency, and side-effect risk in code diffs.
Real-world evidence
Implemented in src/GauntletCI.Core/Rules/Implementations/GCI0036_*.cs.
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.