Upgrading to Angular 10 - Fix CommonJS or AMD dependencies can cause optimization bailouts
JavascriptAngularRxjsRxjs6Angular UpgradeJavascript Problem Overview
I am trying to upgrade my angular 9 app to angular 10 version, but getting below warning after the upgrade
rxjs\BehaviorSubject.js depends on rxjs-compat/BehaviorSubject
Any idea how to fix this?
Javascript Solutions
Solution 1 - Javascript
When you use a dependency that is packaged with CommonJS, it can result in larger slower applications
Starting with version 10, Angular now warns you when your build pulls in one of these bundles. If you’ve started seeing these warnings for your dependencies, let your dependency know that you’d prefer an ECMAScript module (ESM) bundle.
Here is an official documentation - Configuring CommonJS dependencies
In your angular.json file look for the build object and add
> allowedCommonJsDependencies
as shown below -
"build": {
"builder": "@angular-devkit/build-angular:browser",
"options": {
"allowedCommonJsDependencies": [
"rxjs-compat",
... few more commonjs dependencies ...
]
...
}
...
},
Solution 2 - Javascript
try replacing the rxjs imports rxjs/internal/operators
with rxjs/operators
.
ex:
import { catchError, retry } from 'rxjs/internal/operators';
with
import { catchError, retry } from 'rxjs/operators';
Solution 3 - Javascript
It is recommended that you avoid depending on CommonJS modules in your Angular applications. Depending on CommonJS modules can prevent bundlers and minifiers from optimizing your application, which results in larger bundle sizes. Instead, it is recommended that you use ECMAScript modules in your entire application.Still you don't care about your bundling size,
To disable these warnings, you can add the CommonJS module name to allowedCommonJsDependencies
option in the build options located in angular.json
file.
"build": {
"builder": "@angular-devkit/build-angular:browser",
"options": {
"allowedCommonJsDependencies": [
"rxjs-compat"
]
...
}
...
},
Solution 4 - Javascript
For RXJS library you can do following changes.
For imports such as 'rxjs/internal/<anything>'
and 'rxjs/index'
, replace it with just 'rxjs'
.
For imports such as 'rxjs/internal/operators'
, replace it with 'rxjs/operators'
, which is mentioned in @Janardhan Burle's answer.
Or replace just rxjs
Solution 5 - Javascript
Just change the import:
from:
import { BehaviorSubject } from 'rxjs/internal/BehaviorSubject';
To:
import { BehaviorSubject } from 'rxjs';
Solution 6 - Javascript
Another case of this is problem being warned about during the build is with the use of BehaviorSubject
from rxjs
when using the following style of imports:
import { BehaviorSubject } from 'rxjs/BehaviorSubject';
It results in the following error:
> Warning: my.service.ts depends on 'rxjs/BehaviorSubject'. CommonJS or > AMD dependencies can cause optimization bailouts.
By importing from the root module instead, the warning is no longer present during the build:
import { BehaviorSubject } from 'rxjs';
Solution 7 - Javascript
In my case (after update to TypeScript version 3.9.7) flatMap
is deprecated (from rxjs/operators
).
This is alias for mergeMap
, so just I replaced:
import { flatMap } from 'rxjs/internal/operators';
to
import { mergeMap } from 'rxjs/operators';
Solution 8 - Javascript
I had similar issue (app.module.ts depends on 'ngx-google-places-autocomplete'), but many answers did not helped me.
So if you have x depends on y, just add y in angular.json file in "allowedCommonJsDependencies".
Solution 9 - Javascript
I has vary big project with deprecated imports 'rxjs' and create this script for upgrade all deprecated imports
$ python3.6 replace_imports.py PATH_TO_SRC_DIR
this script upgrade import like "rxjs\/(internal|Observable|Subject|ReplaySubject|Subscription|BehaviorSubject)"
to
import { * } from rxjs
also try upgrade rxjs-compat