LowFile-scopeC# Plug & play

Extract duplicated business logic

Move repeated domain rules into reusable methods/services; keep controllers and handlers thin.

Why this matters

Single source of truth improves correctness and testability.

Side-by-side examples engineers can pattern-match during review.

Avoid

total += item.Price * item.Qty; // copied across files

Prefer

decimal LineTotal(Item i) => i.Price * i.Qty;
var total = items.Sum(LineTotal);

Bad

price*qty repeated in loops

Good

Sum(items.Select(LineTotal))

From the same buckets as this rule.

Critical
Avoid Duplicating String Literals
Store repeated string literals in constants or variables to improve maintainability and reduce redundancy.
duplication-complexitymaintainability
Critical
Avoid Redundant `None` Comparisons
Identify cases where `x is None` or `x is not None` is used redundantly when `x` is always or never `None`. This may indicate a deeper logic issue.
duplication-complexityreadability-refactor+1
High
Avoid Functions That Always Return the Same Value
Identify functions that return the same value regardless of input. This may indicate poor design or a logic error.
duplication-complexityreadability-refactor+1