How can I import Web3js into an Ionic/Angular project?

Issue

I've been trying to install Web3 into my Ionic v4 project for a while now. It keeps throwing errors when I serve the project.

Here's what I have so far. I installed web3 using

npm install --save web3

This is what the service that uses it looks like, quite simple, only for testing.

import { Injectable } from '@angular/core';
import Web3 from 'web3';

@Injectable({
  providedIn: 'root'
})
export class Web3Service {

  constructor() { }

  web3 = new Web3(new Web3.providers.HttpProvider('https://ropsten.infura.io/v3/INFURA_API_KEY_HERE')); // removed api key for obvious reasons

  logThings() {
    console.log(this.web3);
  }
}

Heres what my package.json looks like:

{
  "name": "webb3",
  "version": "0.0.1",
  "author": "Ionic Framework",
  "homepage": "https://ionicframework.com/",
  "scripts": {
    "ng": "ng",
    "start": "ng serve",
    "build": "ng build",
    "test": "ng test",
    "lint": "ng lint",
    "e2e": "ng e2e"
  },
  "private": true,
  "dependencies": {
    "@angular/common": "^7.2.2",
    "@angular/core": "^7.2.2",
    "@angular/forms": "^7.2.2",
    "@angular/http": "^7.2.2",
    "@angular/platform-browser": "^7.2.2",
    "@angular/platform-browser-dynamic": "^7.2.2",
    "@angular/router": "^7.2.2",
    "@ionic-native/core": "^5.0.0",
    "@ionic-native/splash-screen": "^5.0.0",
    "@ionic-native/status-bar": "^5.0.0",
    "@ionic/angular": "^4.0.0",
    "@ionic/pro": "2.0.4",
    "core-js": "^2.5.4",
    "rxjs": "~6.3.3",
    "web3": "^1.0.0-beta.39",
    "zone.js": "~0.8.29"
  },
  "devDependencies": {
    "@angular-devkit/architect": "~0.12.3",
    "@angular-devkit/build-angular": "~0.12.3",
    "@angular-devkit/core": "~7.2.3",
    "@angular-devkit/schematics": "~7.2.3",
    "@angular/cli": "~7.2.3",
    "@angular/compiler": "~7.2.2",
    "@angular/compiler-cli": "~7.2.2",
    "@angular/language-service": "~7.2.2",
    "@ionic/angular-toolkit": "~1.2.0",
    "@types/jasmine": "~2.8.8",
    "@types/jasminewd2": "~2.0.3",
    "@types/node": "^10.12.18",
    "codelyzer": "~4.5.0",
    "jasmine-core": "~2.99.1",
    "jasmine-spec-reporter": "~4.2.1",
    "karma": "~3.1.4",
    "karma-chrome-launcher": "~2.2.0",
    "karma-coverage-istanbul-reporter": "~2.0.1",
    "karma-jasmine": "~1.1.2",
    "karma-jasmine-html-reporter": "^0.2.2",
    "protractor": "~5.4.0",
    "ts-node": "~8.0.0",
    "tslint": "~5.12.0",
    "typescript": "~3.1.6"
  },
  "description": "An Ionic project"
}

Here are the errors I'm getting:

[ng] ERROR in node_modules/web3-bzz/types/index.d.ts(28,27): error TS2580: Cannot find name 'Buffer'. Do you need to install type definitions for node? Try `npm i @types/node`.
[ng] node_modules/web3-bzz/types/index.d.ts(30,60): error TS2580: Cannot find name 'Buffer'. Do you need to install type definitions for node? Try `npm i @types/node`.
[ng] node_modules/web3-core/types/index.d.ts(20,22): error TS2307: Cannot find module 'net'.
[ng] node_modules/web3-providers/types/index.d.ts(23,22): error TS2307: Cannot find module 'net'.
[ng] node_modules/web3-utils/types/index.d.ts(71,54): error TS2580: Cannot find name 'Buffer'. Do you need to install type definitions for node? Try `npm i @types/node`.
[ng] node_modules/web3-utils/types/index.d.ts(72,48): error TS2580: Cannot find name 'Buffer'. Do you need to install type definitions for node? Try `npm i @types/node`.
[ng] node_modules/web3/types/index.d.ts(22,22): error TS2307: Cannot find module 'net'.
[ng]
[ng] i ｢wdm｣: Failed to compile.

I'm not entirely sure what I'm doing wrong here so any help at all is much appreciated. Thank you.

Solution

See this GitHub comment for a temporary fix:

This is a mismatch issue with the angular-cli-files default browser.js settings and is something you have to fix to get web3 to work on angular apps.

If you create a file called patch.js in the root of the angular app, then in your package.json under scripts add "postinstall": "node patch.js". run npm install again and then ng build will work and you shouldn't have any more issues.

This is because we have to replace the node:false in the /angular-cli-files/models/webpack-configs/browser.js with 'node: {crypto: true, stream: true}' to allow web3 to work with angular (as they enforce node: false).

A permanent fix for this will be deployed in the next version of web3.js; the PR is:

https://github.com/ethereum/web3.js/pull/2262

Answered By - Josh Stevens