firebase functions typescript で @google-cloud/pubsub(@2.5.x) を使う

普通に import して使うと ビルドエラー

import { PubSub } from '@google-cloud/pubsub';
# ...

tsc
=> 
node_modules/@google-cloud/pubsub/build/src/v1/publisher_client.d.ts(163,103): error TS2304: Cannot find name 'AsyncIterable'.
node_modules/@google-cloud/pubsub/build/src/v1/publisher_client.d.ts(218,127): error TS2304: Cannot find name 'AsyncIterable'.
node_modules/@google-cloud/pubsub/build/src/v1/publisher_client.d.ts(273,119): error TS2304: Cannot find name 'AsyncIterable'.
node_modules/@google-cloud/pubsub/build/src/v1/subscriber_client.d.ts(202,117): error TS2304: Cannot find name 'AsyncIterable'.
node_modules/@google-cloud/pubsub/build/src/v1/subscriber_client.d.ts(257,109): error TS2304: Cannot find name 'AsyncIterable'.

tsconfig.json を修正

{
  "compilerOptions": {
    ...
+    "lib": ["ESNext.AsyncIterable"]
  },
  ...
}

再ビルド

tsc
=>
node_modules/@google-cloud/pubsub/node_modules/@grpc/grpc-js/build/src/call.d.ts(68,5): error TS2416: Property '_write' in type 'ClientWritableStreamImpl<RequestType>' is not assignable to the same property in base type 'Writable'.
   Type '(chunk: RequestType, encoding: string, cb: WriteCallback) => void' is not assignable to type '(chunk: any, encoding: string, callback: (err?: Error | undefined) => void) => void'.
     Types of parameters 'cb' and 'callback' are incompatible.
       Types of parameters 'err' and 'error' are incompatible.
         Type 'Error | null | undefined' is not assignable to type 'Error | undefined'.
           Type 'null' is not assignable to type 'Error | undefined'.

...

nodeのtypeが古いと(8とか？）通らないので追加する

npm install --save-dev @types/node@latest

再ビルド

tsc
=>

やっと通った。。。何したかったんだっけ？？？？