context-type-inference

SKILL.md

Separating a value from its context can cause type errors.

TypeScript infers types based on both the value AND where it's used. When you extract a value to a variable, you lose context, which can cause surprising type errors.

Note: as const makes it readonly. If the function expects a mutable tuple, this won't work:

Use when extracting values causes type errors. Use when callback types are wrong. Use when const assertions are needed. Source: marius-townhouse/effective-typescript-skills.

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