conditional-types-over-overloads

SKILL.md

When a function's return type depends on its input type, you might reach for overload signatures. However, conditional types often provide a better solution. Unlike overloads, which are checked independently, conditional types distribute over unions and can be analyzed as a single expression. This makes them more powerful for handling union inputs and results in more maintainable type declarations.

Understanding when to use conditional types versus overloads is key to writing flexible, correct type signatures.

Prefer conditional types to overloaded signatures. Conditional types distribute over unions and provide more precise, maintainable type declarations.

複数の戻り値の型を持つ関数を入力するときに使用します。関数の動作が入力タイプに依存する場合に使用します。共用体型の入力を処理する場合に使用します。関数のオーバーロードを考慮する場合に使用します。 ソース: marius-townhouse/effective-typescript-skills。

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