将值分配给TypeScript中的类属性

当我需要在TypeScript中为我的类属性分配值但出现错误时，我在做什么错： ERROR : uncaughtException: Cannot set property 'auth' of undefined

我需要auth最初不保留任何信息的属性（1）来保存我在done方法中分配的信息。但是，每当我想为该属性分配任何值时，在我的情况下它都不起作用。我已经检查了很多次，并且在done方法中的auth不是未定义的。它保存传递给它的信息，但无论如何都会弹出错误。

Setters而且Getters也没有帮助。

如果我需要在Angular中分配此值，那肯定可以，但是我想Class的使用会有些许差异。

import fs from 'fs';
import readline from "readline";
import { google } from "googleapis";
import path from 'path';
import { logger } from './winston';

class connectGoogleAPI {

    private SCOPES = [
        'https://www.googleapis.com/auth/gmail.readonly',
        'https://www.googleapis.com/auth/gmail.modify',
        'https://www.googleapis.com/auth/gmail.compose',
        'https://www.googleapis.com/auth/gmail.send'
    ];

    private readonly token_path = path.join(process.cwd(), 'token.json');
    private readonly credential_path = path.join(process.cwd(), 'credentials.json');
    private auth: any = 'value from auth';

    set _auth(auth: any) {
        this.auth = auth;
    }

    get _auth(): any {
        return this.auth;
    }

    constructor() {
    }

    private done(_a: any) {
        this.auth = _a;
        // this.auth = (_a as object);
        // console.log('done');

    }

    connect() {
        // console.log('connect');

        // Load client secrets from a local file.
        fs.readFile(this.credential_path, { encoding: 'utf-8' }, (err: any, content: any) => {
            if (err) return console.log('Error loading client secret file:', err);
            // Authorize a client with credentials, then call the Gmail API.
            this.authorize(JSON.parse(content), this.done);
            // authorize(JSON.parse(content), listLabels);
        });
    }

    private authorize(credentials: any, callback: any) {
        // console.log('authorize');

        const { client_secret, client_id, redirect_uris } = credentials.web;
        const oAuth2Client = new google.auth.OAuth2(
            client_id, client_secret, redirect_uris[0]);

        // Check if we have previously stored a token.
        fs.readFile(this.token_path, { encoding: 'utf-8' }, (err: any, token: any) => {
            if (err) return this.getNewToken(oAuth2Client, callback);
            oAuth2Client.setCredentials(JSON.parse(token));
            logger.info(`Connected to Google API successfully`);
            callback(oAuth2Client);
        });
    }

    private getNewToken(oAuth2Client: any, callback: any) {
        // console.log('getNewToken');

        const authUrl = oAuth2Client.generateAuthUrl({
            access_type: 'offline',
            scope: this.SCOPES,
        });
        logger.warn('Authorize this app by visiting this url:', authUrl);
        const rl = readline.createInterface({
            input: process.stdin,
            output: process.stdout,
        });
        rl.question('Enter the code from that page here: ', (code: any) => {
            rl.close();
            oAuth2Client.getToken(code, (err: any, token: any) => {
                if (err) return logger.error('Error retrieving access token', err);
                oAuth2Client.setCredentials(token);
                // Store the token to disk for later program executions
                fs.writeFile(this.token_path, JSON.stringify(token), (err: any) => {
                    if (err) return console.error(err);
                    logger.info('Token stored to', this.token_path);
                });
                return callback(oAuth2Client);
            });
        });

    }

    getAuth() {
        if (this.auth === null || this.auth === undefined) {
            logger.warn('Getting again auth - Google API');
            this.connect();
        }
        return this.auth;
    }

}

export const googleAPI = new connectGoogleAPI();

我将不胜感激任何帮助和提示。

1.我已经尝试在构造函数中分配一些信息，所以它不是空的，但它也能正常工作