Adding @google-cloud/logging in typescript functions project gives error

Question

EDIT: for others with the same problem - using const Logging: any = require('@google-cloud/logging') together with var logger = Logging() in the body of the class worked like a charm!

Remember to use var logger = Logging() to instantiate the logger library. Otherwise you will still get the logger.log is not a function!

Original post

I've got a firebase functions project, written in typescript - transpiled with webpack. I'm currently trying to implement the @google-cloud/logging library, but I'm having issues. It comes out saying

Could not find a declaration file for module "google-cloud/logging". Try npm install @types/@google-cloud/logging if it exists or add a new declaration (.d.ts) file containing declare module '@google-cloud/logging';

I've tried adding the library the following ways:

import * as Logging from '@google-cloud/logging';
import * as logging from '@google-cloud/logging';
import { Logging } from '@google-cloud/logging';

But I'm still getting this error. Trying to run a function which is using "logging" results in

logging.log is not a function

I have even tried the javascript way of requiring the library, still with no success.

My tsconfig.json:

{
    "compilerOptions": {
        "target": "es6",
        "module": "commonjs",
        "outDir": "./",
        "noImplicitAny": true
    },
    "include": [
        "src/**/*.ts"
    ],
    "exclude": [
        "node_modules"
    ]
}

I've read that some people had success by adding a "d.ts" file to the project manually, though I did not understand much of it. Here is the link to the article in stack overflow - Importing non-typescript module in typescript

How might I go about adding the library in a typescript project?

I can provide more details if needed. This was what I could think of including.

Answer 1

There is not yet type definitions for @google-cloud/logging. So you need to provide some ! In the meantime, you can do

const Logging: any = require('@google-cloud/logging')

If you have @types/node installed and target nodejs or if you target the browser but use "moduleResolution": "CommonJS" (you also need to provide node typefs).

Otherwise, you can use

import * as Logging from '@google-cloud/logging'

But in that case you need to declare the types for this module

// logging.d.ts
declare module '@google-cloud/logging' {

  interface LogConfig {
    removeCircular: boolean
  }

  class Entry {
    metadata: object
    data: object
    constructor (metadata: object | null | undefined, data: object | string)
    constructor (data: object | string)
    toJSON (options?: LogConfig): any
  }

  interface WriteOptions {
    gaxOptions: object
    labels: object[]
    resource: object
  }

  type LogWriteCallback = (err: Error | null, apiResponse: object) => void
  type DeleteLogCallback = (err: Error | null, apiResponse: object) => void

  type LogWriteResponse = object[]
  type DeleteLogResponse = object[]

  type EntryArg = Entry | Entry[]

  class Log {
    constructor (logging: Logging, name: string, options: LogConfig)
    alert (entry: EntryArg, options?: WriteOptions, callback?: LogWriteCallback): Promise<LogWriteResponse>
    critical (entry: EntryArg, options?: WriteOptions, callback?: LogWriteCallback): Promise<LogWriteResponse>
    debug (entry: EntryArg, options?: WriteOptions, callback?: LogWriteCallback): Promise<LogWriteResponse>
    emergency (entry: EntryArg, options?: WriteOptions, callback?: LogWriteCallback): Promise<LogWriteResponse>
    info (entry: EntryArg, options?: WriteOptions, callback?: LogWriteCallback): Promise<LogWriteResponse>
    notice (entry: EntryArg, options?: WriteOptions, callback?: LogWriteCallback): Promise<LogWriteResponse>
    warning (entry: EntryArg, options?: WriteOptions, callback?: LogWriteCallback): Promise<LogWriteResponse>
    error (entry: EntryArg, options?: WriteOptions, callback?: LogWriteCallback): Promise<LogWriteResponse>
    write (entry: EntryArg, options?: WriteOptions, callback?: LogWriteCallback): Promise<LogWriteResponse>
    delete (gaxOptions: object): Promise<DeleteLogResponse>
    delete (gaxOptions: object, callback?: DeleteLogCallback): Promise<DeleteLogResponse>
    delete (callback?: DeleteLogCallback): Promise<DeleteLogResponse>
  }

  interface ClientConfig {
    projectId?: string
    keyFilename?: string
    email?: string
    credentials?: {
      client_email: string
      private_key: string
    }
    autoRetry?: boolean
    maxRetries?: number
    promise?: Function
  }

  class Logging {
    constructor (options: ClientConfig)
    log (name: string, options?: LogConfig): Log
    entry (resource: object | string | null | undefined, data: object | string): Entry
  }
  export = Logging
}

This definition is just a draft and a lot of functions are missing, but I guess it's a necessary first step :-)