StartsWith<T, U>

JSのstartsWith()の型版

code:ts

type StartsWith<T extends string, U extends string> =

T extends ${U}${string}

? true

: false;

例

code:ts

type cases = [

Expect<Equal<StartsWith<'abc', 'ac'>, false>>,

Expect<Equal<StartsWith<'abc', 'ab'>, true>>,

Expect<Equal<StartsWith<'abc', 'abc'>, true>>,

Expect<Equal<StartsWith<'abc', 'abcd'>, false>>,

Expect<Equal<StartsWith<'abc', ''>, true>>,

Expect<Equal<StartsWith<'abc', ' '>, false>>,

Expect<Equal<StartsWith<'', ''>, true>>,

];