Error: Can't resolve 'crypto'

[yunwwang]

Expected Behavior

Angular 6 app launches without error

Actual Behavior

Angular 6 app launches with "Can't resolve 'crypto'" error

Steps to Reproduce the Problem

1. Create an angular 6 app

2. install fhir-kit-client using npm

3. import fhir-kit-client to component

4. add code to noOnInit()
   `
   public ngOnInit(): void {
   const Client = require('fhir-kit-client');
   const iss = this._route.snapshot.queryParams['iss'];

   const fhirClient = new Client({baseUrl: iss});
   ...
   }
   `

5. start the app using "ng serve"

Specifications

• Version:
• Platform:
• Subsystem:

[bkaney]

This seems like a dupe of #92.

Upon research, this seems to be a bug in Angular (see: https://blog.lysender.com/2018/07/angular-6-cannot-resolve-crypto-fs-net-path-stream-when-building-angular/).

Can you confirm the workarounds here work for you?

Also see:

• Webpack Config is stripping out Crypto angular/angular-cli#1548
• https://stackoverflow.com/questions/51087330/angular-6-many-cant-resolve-errors-crypto-fs-http-https-net-path-stream

[froid1911]

you are closing #93 because of dupe of #92
and you are closing #92 because of dupe of #93

[bkaney]

Hi @froid1911 — #93 (this one) is currently open? Not sure what you mean by your comment...

In all likelihood we will include instructions on how to adjust the webpack configuration for Angular 6 per the links above. What are your thoughts?

[froid1911]

opsi, thought it got closed. sry for that :-) ........

[yunwwang]

Worked whole afternoon trying to get angular 6 project working. Tried using @angular-builders/custom-webpack. Now ng build works but ng serve still not working. If anyone have a successful angular 6 project using this client js, please let me know.

[bkaney]

I looked at this a bit today. To make requests work on the server for node apps, we use request, (which depends on the crypto library, not avail in the browser). For the browser, we use request-promise-native. However, request-promise-native has a peer dependency of request. Angular doesn't like this even though the polyfill never actually loads the one requiring crypto.

[foxtree]

but ng serve still not working.

@yunwwang

I tried following the guide, here, and it seems to work with Angular-7:
https://codeburst.io/customizing-angular-cli-6-build-an-alternative-to-ng-eject-a48304cd3b21
(^This guide mentions Angular-6 -- if for any reason this does not work with 6, try upgrading to Angular 7?)

• You would have to npm i -D (or, yarn add -D) @angular-builders/dev-server

• The following changes to angular.json seemed to enable ng serve to work with fhir-kit-client:

[yunwwang]

@foxtree Do you mind to create a sample codes for Anguar 6/7? That would be really helpful.

[bkaney]

This should be resolved in 1.4.0 now. Also check out the examples here: https://github.com/Vermonster/fhir-kit-client-examples