Cannot find name 'require' after upgrading to Angular4

Question

I want to use Chart.js within my Angular project. In previous Angular2 versions, I have been doing this well by using a 'chart.loader.ts' which has:

export const { Chart } = require('chart.js');

Then in the component code I just

import { Chart } from './chart.loader';

But after upgrading to cli 1.0.0 and Angular 4, I get the error: "Cannot find name 'require'".

To reproduce the error:

ng new newapp
cd newapp
npm install chart.js --save
echo "export const { Chart } = require('chart.js');" >> src/app/chart.loader.ts
ng serve

In my 'tsconfig.json', I have

"typeRoots": [
  "node_modules/@types"
],

And in 'node_modules/@types/node/index.d.ts' there is:

declare var require: NodeRequire;

So I'm confused.

BTW, I constantly encounter the warning:

[tslint] The selector of the component "OverviewComponent" should have prefix "app"(component-selector)

Though I have set the "prefix": "" in my '.angular-cli.json'. Could it because changing from 'angular-cli.json' to '.angular-cli.json' the cause?

Answer 1

The problem (as outlined in typescript getting error TS2304: cannot find name ' require') is that the type definitions for node are not installed.

With a projected genned with @angular/cli 1.x, the specific steps should be:

Step 1:

Install @types/node with either of the following:

- npm install --save @types/node
- yarn add @types/node -D

Step 2: Edit your src/tsconfig.app.json file and add the following in place of the empty "types": [], which should already be there:

...
"types": [ "node" ],
"typeRoots": [ "../node_modules/@types" ]
...

If I've missed anything, jot a comment and I'll edit my answer.

Answer 2

Will work in Angular 7+

---

I was facing the same issue, I was adding

"types": ["node"]

to tsconfig.json of root folder.

There was one more tsconfig.app.json under src folder and I got solved this by adding

"types": ["node"]

to tsconfig.app.json file under compilerOptions

{
  "extends": "../tsconfig.json",
  "compilerOptions": {
    "outDir": "../out-tsc/app",
    "types": ["node"]  ----------------------< added node to the array
  },
  "exclude": [
    "test.ts",
    "**/*.spec.ts"
  ]
}

Answer 3

Finally I got solution for this, check my App module file :

import { BrowserModule } from '@angular/platform-browser';
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { NgModule } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { HttpModule } from '@angular/http';
import { BrowserAnimationsModule } from '@angular/platform-browser/animations';
import { MaterialModule } from '@angular/material';
import 'hammerjs';
import { ChartModule } from 'angular2-highcharts';
import * as highcharts from 'highcharts';
import { HighchartsStatic } from 'angular2-highcharts/dist/HighchartsService';

import { AppRouting } from './app.routing';
import { AppComponent } from './app.component';

declare var require: any;


export function highchartsFactory() {
      const hc = require('highcharts');
      const dd = require('highcharts/modules/drilldown');
      dd(hc);

      return hc;
}

@NgModule({
  declarations: [
    AppComponent,
  ],
  imports: [
    BrowserModule,
    FormsModule,
    HttpModule,
    AppRouting,
    BrowserAnimationsModule,
    MaterialModule,
    ChartModule
  ],
  providers: [{
      provide: HighchartsStatic,
      useFactory: highchartsFactory
    }],
  bootstrap: [AppComponent]
})
export class AppModule { }

Notice declare var require: any; in the above code.

Answer 4

As for me, using VSCode and Angular 5, only had to add "node" to types in tsconfig.app.json. Save, and restart the server.

{
    "compilerOptions": {
    ..
    "types": [
      "node"
    ]
  }
  ..
}

One curious thing, is that this problem "cannot find require (", does not happen when excuting with ts-node

Answer 5

Still not sure the answer, but a possible workaround is

import * as Chart from 'chart.js';

Answer 6

I added

"types": [ 
   "node"
]

in my tsconfig file and its worked for me tsconfig.json file look like

  "extends": "../tsconfig.json",
  "compilerOptions": {
    "outDir": "../out-tsc/app",
    "baseUrl": "./",
    "module": "es2015",
    "types": [ 
      "node",
      "underscore"
    ]
  },  

Answer 7

Add the following line at the top of the file that gives the error:

declare var require: any

Answer 8

I moved the tsconfig.json file into a new folder to restructure my project.

So it wasn't able to resolve the path to node_modules/@types folder inside typeRoots property of tsconfig.json

So just update the path from

"typeRoots": [
  "../node_modules/@types"
]

to

"typeRoots": [
  "../../node_modules/@types"
]

To just ensure that the path to node_modules is resolved from the new location of the tsconfig.json