Combine linq methods (ARCH605)

Key dotnet.performance.combine-linq-methods · Severity info · Category performance · Principle Kiss

Instead of separate calls like Where then First, putting the predicate into First(...) scans the collection in a single pass.

Incorrect

var first = items
    .Where(i => i.IsActive)
    .First();

Correct

var first = items
    .First(i => i.IsActive);

Fix

Combine filter and selection predicates into one LINQ call.