MCarlomagno

/**
 * Go-like error catching implementation.
 * 
 * The 'attempt' function receives a callback function as a parameter
 * and calls it inside a try catch statement.
 * 
 * Returns a tuple of [data, error] where 'data' (if exists) is the 
 * result of the operation and 'error' (if exists)
 * is the error from the catch statement.
 */

MCarlomagno

import * as ethers from 'ethers';
import { 
  ExternalProvider, 
  JsonRpcSigner, 
  Network, 
  Web3Provider 
} from '@ethersproject/providers';
import { useState } from 'react';

declare global {

MCarlomagno

const untar = await require("js-untar");

async download(file: PersssistFile) {
  const iterable = this.ipfs.get(file.filePath);
  var chunks: Uint8Array[] = [];
  
  // we need to use a for await for downloading 
  // the buffer in chunks.
  for await (const b of iterable) {
      chunks.push(b);

MCarlomagno

    async getFilesMetadata(): Promise<PersssistFile[]> {
        const methods = this.contract.methods;
        const filesCount = await methods.fileCount().call();
        const filesMetadata: PersssistFile[] = [];
        for (var i = filesCount; i >= 1; i--) {
            const file = await methods.files(i).call()
            filesMetadata.push({
                fileId: file.id, 
                fileName: file.fileName, 
                filePath: file.filePath, 

MCarlomagno

  async uploadFileMetadata(
    path: string, 
    size: number, 
    type: string, 
    name: string, 
    account: string,
  ) {
    return this.contract.methods
        .uploadFile(path, size, type, name)
        .send({ from: account })

MCarlomagno

import { create } from "ipfs-http-client";

async upload(file: File) {
    this.ipfs = create({
      host: 'ipfs.infura.io',
      port: 5001,
      protocol: 'https'
    });
  
    const blob = new Blob([file.buffer], { type: file.type });

MCarlomagno

import Web3 from "web3";

// we import the abi file created after 
// the migration using truffle.
import Persssist from '../../public/abis/Persssist.json';


async initializeContractLocal() {
  if (window.ethereum) this.web3 = new Web3(window.ethereum)
  else if (window.web3) this.web3 = new Web3(window.web3.currentProvider);

MCarlomagno

async requestAccounts() {
  if(typeof window === "undefined") return;
  return window
    .ethereum?.request({ method: "eth_requestAccounts" })
    .catch((err: any) => console.log(err));
}

MCarlomagno

async fetchAccounts() {
  if(typeof window === "undefined") return;
  return window
    .ethereum?.request({ method: "eth_accounts" })
    .catch((err: any) => console.log(err));
}

MCarlomagno

  it("uploads a valid file", async () => {
    // checks filecount variable
    // before uploading the file
    const countBeforeUpload = await this.contract.fileCount();
    
    await this.contract.uploadFile('path', 1, 'type', 'name');
    
    // checks filecount increased
    // by one after upload
    const countAfterUpload = await this.contract.fileCount();