Hello all! If I want to extend a external class with some es6+ apis, what is the proper way to do th...

# javascript

[Todd]

Hello all! If I want to extend a external class with some es6+ apis, what is the proper way to do that?

I tried to do an extension function (although I know that doesn't really makes sense) like

external fun Blob.stream(): Promise<ReadableStream>

But the compiler told me that's illegal. Intellij suggested I change it to

@Suppress("NOTHING_TO_INLINE")
inline fun Blob.stream(): Promise<ReadableStream> = asDynamic().stream() as Promise<ReadableStream>

which I think will work for me, but I was wondering if anyone knows of a better way to do this?

[turansky]

Type already known, no cast required:

inline fun Blob.stream(): Promise<ReadableStream> =     asDynamic().stream().unsafeCast<Promise<ReadableStream>>()

[turansky]

Extension - most Kotlinish solution

[Todd]

Interesting. Extension functions feel more like an implementation then defining an external interface so I felt like there might be something else (without redefining the whole clas). But this works! Thanks!

[turansky]

FYI - Type-safe sugar