JavaScript/tutorials/backend/example-nestjs/src/file.service.ts at main · mdlufy/JavaScript · GitHub

38 lines (29 loc) · 798 Bytes

import { Injectable } from '@nestjs/common';

import * as fs from 'fs';

import * as path from 'path';

export interface FileAccessor {

filePath: string;

}

@Injectable()

export class FileService<I> {

protected readonly filePath = path.resolve(__dirname);

constructor(filePath?: string) {

if (filePath) {

this.filePath = path.resolve(__dirname, filePath);

}

public read<T extends I>(): T {

const data = fs.readFileSync(this.filePath, 'utf8');

return JSON.parse(data) as T;

}

public add<T>(newData: T): void {

const data = this.read();

if (Array.isArray(data)) {

data.push(newData);

}

this.write(data);

}

public write<T extends I>(data: T): void {

fs.writeFileSync(this.filePath, JSON.stringify(data, null, 2), 'utf8');

}

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