@fastify/caching/types/index.test-d.ts

A plugin for Fastify to enable management of cache control headers

import Fastify, { FastifyReply } from 'fastify'
import { expectAssignable, expectError, expectType } from 'tsd'
import fastifyCaching, {
  AbstractCacheCompliantObject,
  FastifyCachingPluginOptions,
} from '..'

const fastify = Fastify({ logger: true })

const cachingOptions: FastifyCachingPluginOptions = {
  privacy: fastifyCaching.privacy.PUBLIC,
  expiresIn: 300,
  cacheSegment: 'fastify-caching',
}
expectAssignable<FastifyCachingPluginOptions>(cachingOptions)

fastify.register(fastifyCaching, cachingOptions)

expectType<AbstractCacheCompliantObject>(fastify.cache)
expectType<AbstractCacheCompliantObject['get']>(fastify.cache.get)
expectType<AbstractCacheCompliantObject['set']>(fastify.cache.set)
expectType<string>(fastify.cacheSegment)
// expectType<number>(fastify.etagMaxLife);

fastify.get('/one', async (_request, reply) => {
  expectType<(tag?: string, timeToLive?: number) => FastifyReply>(reply.etag)
  expectType<(date?: Date) => FastifyReply>(reply.expires)

  expectType<FastifyReply>(reply.etag('hello', 6000))
  expectType<FastifyReply>(reply.expires(new Date(Date.now() + 6000)))

  return { message: 'one' }
})

fastify.get('/two', async (_request, reply) => {
  expectType<FastifyReply>(
    reply.etag('hello', 6000).expires(new Date(Date.now() + 6000))
  )

  return { message: 'two' }
})

// We register a new instance that should trigger a typescript error.
const shouldErrorApp = Fastify({ logger: true })

const badCachingOptions = {
  privacy: fastifyCaching.privacy.PRIVATE,
  expiresIn: 'a string instead of a number of second',
  cacheSegment: 'fastify-caching',
}

expectError(shouldErrorApp.register(fastifyCaching, badCachingOptions))

fastify.get('/three', async () => {
  expectAssignable<Promise<unknown>>(
    fastify.cache.get('well-known')
  )
  expectAssignable<Promise<{ item: string; stored: number; ttl: number; } | null>>(
    fastify.cache.get<string>('well-known')
  )
  expectType<void>(
    fastify.cache.get<string>('well-known', (err, value) => {
      expectType<unknown>(err)
      expectAssignable<{ item: string; stored: number; ttl: number; } | null>(value)
    })
  )

  return { message: 'two' }
})