UnhandledPromiseRejectionWarning: Error: Multiple root routing modules found

[keserwan]

I am trying to do npx angular-prerender after I doing a successful ng build

I got this error:
PS C:\Development\xyz\ClientApps> npx angular-prerender
(node:1384) UnhandledPromiseRejectionWarning: Error: Multiple root routing modules found C:\Development\xyz\ClientApps\libs\shared\src\lib\shared-routing.module.ts, C:\Development\xyz\ClientApps\apps\website\src\app\app.module.ts, C:\Development\xyz\ClientApps\libs\about\src\lib\about-routing.module.ts, C:\Development\xyz\ClientApps\libs\agent\src\lib\agent-routing.module.ts, C:\Development\xyz\ClientApps\libs\camp\src\lib\camp-routing.module.ts, C:\Development\xyz\ClientApps\libs\flight\src\lib\flight-routing.module.ts, C:\Development\xyz\ClientApps\libs\game\src\lib\game-routing.module.ts, C:\Development\xyz\ClientApps\libs\giftcard\src\lib\gift-card-routing.module.ts, C:\Development\xyz\ClientApps\libs\home\src\lib\home-routing.module.ts, C:\Development\xyz\ClientApps\libs\profile\src\lib\profile-routing.module.ts, C:\Development\xyz\ClientApps\libs\trip\src\lib\trip-routing.module.ts
at findRootModule (C:\Development\xyz\ClientApps\node_modules\guess-parser\dist\guess-parser\index.js:412:15)
at exports.parseRoutes (C:\Development\xyz\ClientApps\node_modules\guess-parser\dist\guess-parser\index.js:575:31)
at prerender (C:\Development\xyz\ClientApps\node_modules\angular-prerender\build\node\functions\prerender.js:89:54)
(node:1384) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:1384) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with
a non-zero exit code.

I have 3 angular apps and several libraries, but I tried to prerender the default app.

here are my configurations:
ng --version

 _                      _                 ____ _     ___ 
/ \   _ __   __ _ _   _| | __ _ _ __     / ___| |   |_ _|

/ △ \ | '_ \ / | | | | |/ _ | '__| | | | | | |
/ ___ | | | | (| | || | | (| | | | || | | |
// __| ||_, |_,||_,|| _|||
|___/

Angular CLI: 8.3.6
Node: 12.4.0
OS: win32 x64
Angular: 8.2.8
... animations, common, compiler, compiler-cli, core, forms
... language-service, platform-browser, platform-browser-dynamic
... platform-server, router, service-worker, upgrade

Package Version

@angular-devkit/architect 0.803.3
@angular-devkit/build-angular 0.803.6
@angular-devkit/build-ng-packagr 0.803.6
@angular-devkit/build-optimizer 0.803.6
@angular-devkit/build-webpack 0.803.6
@angular-devkit/core 8.3.6
@angular-devkit/schematics 8.3.6
@angular/cdk 8.2.2
@angular/cli 8.3.6
@angular/http 7.2.15
@angular/material 8.2.2
@angular/material-moment-adapter 8.2.2
@angular/pwa 0.803.6
@ngtools/webpack 8.3.6
@nguniversal/common 8.1.1
@nguniversal/express-engine 8.1.1
@nguniversal/module-map-ngfactory-loader 8.1.1
@schematics/angular 8.3.6
@schematics/update 0.803.6
ng-packagr 5.5.1
rxjs 6.5.3
typescript 3.5.3
webpack 4.39.2

[chrisguttandin]

Hi @keserwan,

thanks for the detailed error report. The error you get comes from the guess-parser package. For some reason it seems to be confused. It tries to identify the root module of your app. And according to the algorithm it uses there is more than one root module.

https://github.com/guess-js/guess/blob/master/packages/guess-parser/src/angular/index.ts#L295

It works by analyzing the dependency tree that's formed by all the NgModules. Every NgModule which is not required by another NgModule is considered a root module. Normally there is only one NgModule which satisfies that constraint. But in your case it looks like it identified the root NgModule of all your libraries as well. Is that possible?

\libs\shared\src\lib\shared-routing.module.ts
\apps\website\src\app\app.module.ts
\libs\about\src\lib\about-routing.module.ts
\libs\agent\src\lib\agent-routing.module.ts
\libs\camp\src\lib\camp-routing.module.ts
\libs\flight\src\lib\flight-routing.module.ts
\libs\game\src\lib\game-routing.module.ts
\libs\giftcard\src\lib\gift-card-routing.module.ts
\libs\home\src\lib\home-routing.module.ts
\libs\profile\src\lib\profile-routing.module.ts
\libs\trip\src\lib\trip-routing.module.ts

I tried to modify the default test case to reproduce the problem. However it seems to be not enough to trigger the error. Can you tell me what else I need to do to link the galaxy library into my universe application?

Here are the commands I used:

npx @angular/cli new universe --create-application=false
cd universe/
ng generate application universe --routing
ng generate universal --client-project universe
ng generate library galaxy
npm install angular-prerender --save-dev
ng build
ng run universe:server
npx angular-prerender

[keserwan]

I am using wrapper modules to connect the libraries with the app.
something like this in the app-routing.module.ts

{
path: 'home',
loadChildren: './_wrapper-modules/home-wrapper.module#HomeWrapperModule'
},

and in HomeWrapperModule.ts I am importing the lib:

import { NgModule } from '@angular/core'
import { HomeModule } from '@xyz-xyz-web/home';

@NgModule(
{
imports: [
HomeModule
]
}
)
export class HomeWrapperModule { }

[chrisguttandin]

I would assume that the HomeModule is located at \libs\home\src\lib\home.module.ts. Is that correct? Is the NgModule defined in \libs\home\src\lib\home-routing.module.ts imported by the HomeModule?

[keserwan]

Yes right, ur assumption is correct.
Sorry I didn't mention the configuration in main tsconfig.json file:

"paths": {
  "moment": [
    "../node_modules/moment/min/moment.min.js"
  ],
  "@xyz-xyz-web/*": ["@xyz-xyz-web/*"],
  "@xyz-xyz-web/utilities": ["libs/utilities/src/index.ts"],
  "@xyz-xyz-web/shared": ["libs/shared/src/index.ts"],
  "@xyz-xyz-web/material": ["libs/material/src/index.ts"],
  "@xyz-xyz-web/core": ["libs/core/src/index.ts"],
  "@xyz-xyz-web/flight": ["libs/flight/src/index.ts"],
  "@xyz-xyz-web/trip": ["libs/trip/src/index.ts"],
  "@xyz-xyz-web/about": ["libs/about/src/index.ts"],
  "@xyz-xyz-web/agent": ["libs/agent/src/index.ts"],
  "@xyz-xyz-web/camp": ["libs/camp/src/index.ts"],
  "@xyz-xyz-web/game": ["libs/game/src/index.ts"],
  "@xyz-xyz-web/giftcard": ["libs/giftcard/src/index.ts"],
  "@xyz-xyz-web/team": ["libs/team/src/index.ts"],
  "@xyz-xyz-web/home": ["libs/home/src/index.ts"],
  "@xyz-xyz-web/profile": ["libs/profile/src/index.ts"]
}

also here is libs/home/src/index.ts:
export * from './lib/home.module';

Knowing that I followed best practices by Nrwl.

[chrisguttandin]

Thanks a lot. I can reproduce the problem now.

I think you ran into two bugs at the same time. guess-parser doesn't handle barrel files so far and it doesn't resolve local links defined as paths in the tsconfig file.

I will try to submit a pull request for guess-parser later today. Once that is merged angular-prerender will hopefully work for you as well.

[keserwan]

Thank you @chrisguttandin

[chrisguttandin]

Hi @keserwan, v4.1.20 should work now. It requires guess-parser v0.4.9 which contains the fix.

But please double-check if it really works. In case it doesn't please feel free to reopen this issue.

[keserwan]

Thank you for your support @chrisguttandin,
I installed v4.1.20
Also I did npm i guess-parser --save-dev, it installed version 0.4.9

I am still getting the below error, after doing the following commands:
Please note that, my angular.json has 3 apps and several libraries, so in the dist folder there will be sub folder for each app. I assume the command "npx angular-prerender" is doing the job for the default app in angular.json?

here are the commands I did:
ng build --configuration=production
ng run website:server:production
npx angular-prerender

here is the output:

PS C:\Development\xyz\ClientApps> npx angular-prerender
(node:14520) UnhandledPromiseRejectionWarning: Error: Multiple root routing modules found C:\Development\xyz\ClientApps\libs\shared\src\lib\shared-routing.module.ts, C:\Development\xyz\ClientApps\apps\website\src\app\app-routing.module.ts, C:\Development\xyz\ClientApps\libs\about\src\lib\about-routing.module.ts, C:\Development\xyz\ClientApps\libs\agent\src\lib\agent-routing.module.ts, C:\Development\xyz\ClientApps\libs\camp\src\lib\camp-routing.module.ts, C:\Development\xyz\ClientApps\libs\flight\src\lib\flight-routing.module.ts, C:\Development\xyz\ClientApps\libs\game\src\lib\game-routing.module.ts, C:\Development\xyz\ClientApps\libs\giftcard\src\lib\gift-card-routing.module.ts, C:\Development\xyz\ClientApps\libs\home\src\lib\home-routing.module.ts, C:\Development\xyz\ClientApps\libs\profile\src\lib\profile-routing.module.ts, C:\Development\xyz\ClientApps\libs\trip\src\lib\trip-routing.module.ts
at findRootModule (C:\Development\xyz\ClientApps\node_modules\guess-parser\dist\guess-parser\index.js:419:15)
at exports.parseRoutes (C:\Development\xyz\ClientApps\node_modules\guess-parser\dist\guess-parser\index.js:582:31)
at prerender (C:\Development\xyz\ClientApps\node_modules\angular-prerender\build\node\functions\prerender.js:89:54)
(node:14520) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:14520) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

[chrisguttandin]

Thanks for checking it again.

Sadly that error looks very familiar. It's almost the same as the one that we started with. Only the app.module.ts has been replaced by the app-routing.module.ts.

There is no chance for me to access your repo, right? The test case that I build to reproduce the error did work as expected.

[keserwan]

I prepared a project with the same structure on this repo
I am able to reproduce the issue on it too
https://github.com/keserwan/testAngularPrerender

[chrisguttandin]

Thanks a lot. I will take a look.

[chrisguttandin]

I made a little mistake in the last pull request. I created another pull request to fix it. guess-js/guess#247

[keserwan]

Thank you for your contributions!

[chrisguttandin]

Hi @keserwan, can you please try it once more with v1.4.21. It does at least work with your demo project.

You can also uninstall guess-parser if you don't use it for anything else. It doesn't need to be an explicit dependency as it is bundled with angular-prerender.

[keserwan]

Sorry for the late reply, I will check tomorrow and let you know, thank you very much for your contributions

[keserwan]

Hi @chrisguttandin, I updated angular-prerender to 4.1.21, deleted node-modules & package-lock.json and did the following again:

npm i
npm run build:ssr
npx angular-prerender

Note: I pushed the changes to my demo repo, https://github.com/keserwan/testAngularPrerender

I am getting this error now:

PS C:\Development\test\New folder> npx angular-prerender
(node:2188) UnhandledPromiseRejectionWarning: Error: Multiple root routing modules found C:\Development\test\New folder\apps\website\src\app\app-routing.module.ts, C:\Development\test\New folder\libs\about\src\lib\about-routing.module.ts, C:\Development\test\New folder\libs\camp\src\lib\camp-routing.module.ts, C:\Development\test\New folder\libs\game\src\lib\game-routing.module.ts, C:\Development\test\New folder\libs\home\src\lib\home-routing.module.ts
at findRootModule (C:\Development\test\New folder\node_modules\guess-parser\dist\guess-parser\index.js:419:15)
at exports.parseRoutes (C:\Development\test\New folder\node_modules\guess-parser\dist\guess-parser\index.js:582:31)
at prerender (C:\Development\test\New folder\node_modules\angular-prerender\build\node\functions\prerender.js:89:54)
(node:2188) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:2188) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.
PS C:\Development\test\New folder>

[chrisguttandin]

Thanks @keserwan, for testing it again. Since you are using a Windows computer you probably ran into the bug reported here: #88. I'll try to fix that now. Sorry for the back and forth.

[chrisguttandin]

Hi @keserwan, I just published another patch release. Can you please try once more with version 4.1.22. Many thanks in advance.

[keserwan]

THANK YOU!
IT WORKED ON WINDOWS.

[chrisguttandin]

I'm happy to hear that. Thanks for your patience and thanks again for making me aware of the issue in the first place.