LowFile-scopeJavaScript / TypeScript Plug & play

Use computed/derived properties for repeated calculations

Compute expensive derived values once per input set and reuse them rather than recalculating in multiple places.

Why this matters

Reduces duplicate work and logic drift.

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

Avoid

const a = items.reduce(...);
const b = items.reduce(...); // same logic

Prefer

const lineTotal=i=>i.price*i.qty; const total=items.reduce((acc,i)=>acc+lineTotal(i),0);

Bad

recompute the same reduce several times

Good

derive once and reuse

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