fastify - is then method on reply object is a custom method implemented specifically by fastify ?

dilipagheda

fastify - is then method on reply object is a custom method implemented specifically by fastify ?

I can appreciate the await reply. but since reply is not a promise, i wonder it can't call the then method of a promise.

so, i believe then method is implemented seperately on a reply object?

can someone confirm my understanding? highly appreciated.
thank you.

d.m.c

yes the await syntax causes a then method to be called on whatever object is awaited. A plain object with a then method is informally known as a "thenable", Fastify is probably using thenables as a performance optimization (from memory I think awaiting a thenable is faster/uses less resources, for a start it eliminates a lot of the internal mechanics that promises introduce around asynchronous catch handlers).