Return Value to front End after Promise Resolution in Loopback4 - async-await

Question

In the code written below, I am trying to push values in the array finalArray inside 'then'. After that, I need to return the value of finalArray present at point 1 to the front end. How can I achieve this? Putting return statement at point 2 doesn't help. It returns an empty array as expected.
Please help.
// Copyright IBM Corp. 2020. All Rights Reserved.
// Node module: #loopback/example-file-transfer
// This file is licensed under the MIT License.
// License text available at https://opensource.org/licenses/MIT
import {inject} from '#loopback/core';
import {
repository
} from '#loopback/repository';
import {
get,
HttpErrors,
oas,
param,
Response,
RestBindings
} from '#loopback/rest';
import fs from 'fs';
import path from 'path';
import {promisify} from 'util';
import {STORAGE_DIRECTORY} from '../keys';
import {DocStoreRepository, MetadataCommonRepository} from '../repositories';
const readdir = promisify(fs.readdir);
/**
* A controller to handle file downloads using multipart/form-data media type
*/
export class FileDownloadController {
constructor(#inject(STORAGE_DIRECTORY) private storageDirectory: string,
#repository(MetadataCommonRepository) public metadataCommonRepository: MetadataCommonRepository,
#repository(DocStoreRepository) public docStoreRepository: DocStoreRepository,
) { }
finalArray: any = [];
// finalArray1: any = [];
// ObjofFinalArray = {}
#get('/files', {
responses: {
200: {
content: {
// string[]
'application/json': {
schema: {
type: 'array',
items: {
type: 'string',
},
},
},
},
description: 'A list of files',
},
},
})
async listFiles() {
const files = await readdir(this.storageDirectory)
var docNameArray = [];
docNameArray = files;
docNameArray.forEach((x, i) => {
//console.log("DocName", x, () => {});
var ObjofFinalArray = {
fileName: "",
DrawingNo: "",
AltNo: "",
SheetNo: ""
};
ObjofFinalArray.fileName = x;
this.docStoreRepository.find({where: {and: [{validFlag: true}, {useFlag: true}, {dsFileName: x}]}}).then((docstoreDataReturned) => {
// console.log("docstoreDataReturned", docstoreDataReturned);
return docstoreDataReturned;
}).then((docstoreDataReturned) => {
this.metadataCommonRepository.find({where: {and: [{validFlag: true}, {useFlag: true}, {mcDocstoreDk: docstoreDataReturned[0].dk}]}}).then((metadataCommonDataReturned) => {
//console.log("metadataCommonData", metadataCommonDataReturned)
ObjofFinalArray.DrawingNo = metadataCommonDataReturned[0].mcDrawNo;
ObjofFinalArray.AltNo = metadataCommonDataReturned[0].mcAltNo;
ObjofFinalArray.SheetNo = metadataCommonDataReturned[0].mcSheetNo;
return ObjofFinalArray;
}).then((ObjofFinalArr) => {
this.finalArray.push(ObjofFinalArr)
}).then(() => {
// console.log("this.finalArray", this.finalArray);
if (this.finalArray.length == files.length) {
console.log("this.finalArray", this.finalArray); /* point 1*/
}
});
})
});
return this.finalArray; /*point 2*/
// return files
}