Typescript WTF Moments 7: Boolean can extends Record<infer X,unknown>

type o = boolean extends Record<infer X, unknown> ? X : false // valueOf
//   ^?

console.log(true.valueOf()) // true

playground

Boolean can extends Record because boolean in JS has properties "valueOf"

this may caught you off guard if you expect anything that extends Record is object type

Comments

[tylim]

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[Acid Coder]

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[tylim]

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