isArray.types

=== tests/cases/compiler/isArray.ts ===
var maybeArray: number | number[];
>maybeArray : number | number[]


if (Array.isArray(maybeArray)) {
>Array.isArray(maybeArray) : boolean
>Array.isArray : <T>(arg: T) => arg is T extends any ? (true extends false & T ? Extract<any[], T> : T extends string | readonly any[] ? never : T extends ArrayLike<infer U> ? Extract<U[], T> : never) | (true extends false & T ? never : {} extends Required<T> ? T & any[] : Extract<T, readonly any[]>) : never
>Array : ArrayConstructor
>isArray : <T>(arg: T) => arg is T extends any ? (true extends false & T ? Extract<any[], T> : T extends string | readonly any[] ? never : T extends ArrayLike<infer U> ? Extract<U[], T> : never) | (true extends false & T ? never : {} extends Required<T> ? T & any[] : Extract<T, readonly any[]>) : never
>maybeArray : number | number[]

    maybeArray.length; // OK
>maybeArray.length : number
>maybeArray : number[]
>length : number
}
else {
    maybeArray.toFixed(); // OK
>maybeArray.toFixed() : string
>maybeArray.toFixed : (fractionDigits?: number) => string
>maybeArray : number
>toFixed : (fractionDigits?: number) => string
}