first_where.md

Pattern: Missing use of .first(where:)

Issue: -

Description

Prefer using .first(where:) over .filter { }.first in collections.

Examples of correct code:

kinds.filter(excludingKinds.contains).isEmpty && kinds.first == .identifier


myList.first(where: { $0 % 2 == 0 })


match(pattern: pattern).filter { $0.first == .identifier }

Examples of incorrect code:

↓myList.filter { $0 % 2 == 0 }.first


↓myList.filter({ $0 % 2 == 0 }).first


↓myList.map { $0 + 1 }.filter({ $0 % 2 == 0 }).first


↓myList.map { $0 + 1 }.filter({ $0 % 2 == 0 }).first?.something()


↓myList.filter(someFunction).first


↓myList.filter({ $0 % 2 == 0 })
.first

Further Reading

• SwiftLint - First Where