62

I was trying to find any solution for this error but nothing works for me. I have simple Angular2 App created with Angular-CLI. When I serve this app in browser I'm getting this error: EXCEPTION: Uncaught (in promise): Error: Cannot find module '/app/test.module'. I was trying using different path in loadChildren:

'/app/test.module'
'./app/test.module'
'./test.module'
'/src/app/test.module'

Folders

src/
  app/
    app-routing.module.ts
    app.component.ts
    app.module.ts
    test.component.ts
    test.module.ts

app.module.ts

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { HttpModule } from '@angular/http';

import { RoutingModule } from './app-routing.module';

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

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    FormsModule,
    HttpModule,
    RoutingModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

app-routing.module.ts

import { NgModule } from '@angular/core';
import { Routes, RouterModule } from '@angular/router';


const routes: Routes = [
  { path: '', loadChildren: '/app/test.module' }
];

@NgModule({
  imports: [RouterModule.forRoot(routes)],
  exports: [RouterModule],
  providers: []
})
export class RoutingModule { }

test.module.ts

import { NgModule } from '@angular/core';
import { Routes, RouterModule } from '@angular/router';
import { CommonModule } from '@angular/common';
import { TestComponent } from './test.component';

export const routes: Routes = [
    { path: '', component: TestComponent }
];

@NgModule({
  imports: [
    CommonModule,
    RouterModule.forChild(routes)
  ],
  exports: [TestComponent],
  declarations: [TestComponent]
})
export default class TestModule { }

stack trace

        error_handler.js:45EXCEPTION: Uncaught (in promise): Error: Cannot find module '/app/test.module'.ErrorHandler.handleError @ error_handler.js:45next @ application_ref.js:273schedulerFn @ async.js:82SafeSubscriber.__tryOrUnsub @ Subscriber.js:223SafeSubscriber.next @ Subscriber.js:172Subscriber._next @ Subscriber.js:125Subscriber.next @ Subscriber.js:89Subject.next @ Subject.js:55EventEmitter.emit @ async.js:74onError @ ng_zone.js:120onHandleError @ ng_zone_impl.js:64ZoneDelegate.handleError @ zone.js:207Zone.runGuarded @ zone.js:113_loop_1 @ zone.js:379drainMicroTaskQueue @ zone.js:386
    2016-10-08 14:22:50.612 error_handler.js:50ORIGINAL STACKTRACE:ErrorHandler.handleError @ error_handler.js:50next @ application_ref.js:273schedulerFn @ async.js:82SafeSubscriber.__tryOrUnsub @ Subscriber.js:223SafeSubscriber.next @ Subscriber.js:172Subscriber._next @ Subscriber.js:125Subscriber.next @ Subscriber.js:89Subject.next @ Subject.js:55EventEmitter.emit @ async.js:74onError @ ng_zone.js:120onHandleError @ ng_zone_impl.js:64ZoneDelegate.handleError @ zone.js:207Zone.runGuarded @ zone.js:113_loop_1 @ zone.js:379drainMicroTaskQueue @ zone.js:386
    2016-10-08 14:22:50.613 error_handler.js:51Error: Uncaught (in promise): Error: Cannot find module '/app/test.module'.
        at resolvePromise (zone.js:429)
        at zone.js:406
        at ZoneDelegate.invoke (zone.js:203)
        at Object.onInvoke (ng_zone_impl.js:43)
        at ZoneDelegate.invoke (zone.js:202)
        at Zone.run (zone.js:96)
        at zone.js:462
        at ZoneDelegate.invokeTask (zone.js:236)
        at Object.onInvokeTask (ng_zone_impl.js:34)
        at ZoneDelegate.invokeTask (zone.js:235)ErrorHandler.handleError @ error_handler.js:51next @ application_ref.js:273schedulerFn @ async.js:82SafeSubscriber.__tryOrUnsub @ Subscriber.js:223SafeSubscriber.next @ Subscriber.js:172Subscriber._next @ Subscriber.js:125Subscriber.next @ Subscriber.js:89Subject.next @ Subject.js:55EventEmitter.emit @ async.js:74onError @ ng_zone.js:120onHandleError @ ng_zone_impl.js:64ZoneDelegate.handleError @ zone.js:207Zone.runGuarded @ zone.js:113_loop_1 @ zone.js:379drainMicroTaskQueue @ zone.js:386
    2016-10-08 14:22:50.614 zone.js:355Unhandled Promise rejection: Cannot find module '/app/test.module'. ; Zone: angular ; Task: Promise.then ; Value: Error: Cannot find module '/app/test.module'.(…) Error: Cannot find module '/app/test.module'.
        at webpackEmptyContext (http://localhost:4200/main.bundle.js:49550:8)
        at SystemJsNgModuleLoader.loadAndCompile (http://localhost:4200/main.bundle.js:57952:40)
        at SystemJsNgModuleLoader.load (http://localhost:4200/main.bundle.js:57945:60)
        at RouterConfigLoader.loadModuleFactory (http://localhost:4200/main.bundle.js:22354:128)
        at RouterConfigLoader.load (http://localhost:4200/main.bundle.js:22346:81)
        at MergeMapSubscriber.project (http://localhost:4200/main.bundle.js:61105:111)
        at MergeMapSubscriber._tryNext (http://localhost:4200/main.bundle.js:32515:27)
        at MergeMapSubscriber._next (http://localhost:4200/main.bundle.js:32505:18)
        at MergeMapSubscriber.Subscriber.next (http://localhost:4200/main.bundle.js:7085:18)
        at ScalarObservable._subscribe (http://localhost:4200/main.bundle.js:48555:24)consoleError @ zone.js:355_loop_1 @ zone.js:382drainMicroTaskQueue @ zone.js:386
    2016-10-08 14:22:50.620 zone.js:357Error: Uncaught (in promise): Error: Cannot find module '/app/test.module'.(…)consoleError @ zone.js:357_loop_1 @ zone.js:382drainMicroTaskQueue @ zone.js:386
7
  • 1
    try loadChildren: '/app/test.module' to change to loadChildren: 'app/test.module' This will work I guess. Commented Oct 8, 2016 at 13:44
  • I tried this before but had the same error Commented Oct 8, 2016 at 14:09
  • 12
    I was troubled by this error all night. At last, I found I just need to stop the ng serve command, and restart. Then the error gone. Because the module will be lazy loaded, maybe there is some work will be done during starting test server. Commented Nov 8, 2016 at 16:02
  • @Mavlarn restart ng serve work for me as well, thanks ! Commented Nov 11, 2016 at 17:27
  • 1
    @arthurr did you use ng build --aot for compilation? cause I get this error only while doing --aot, otherwise it works fine Commented Nov 6, 2017 at 13:21

16 Answers 16

71

restarting ng serve worked for me

Sign up to request clarification or add additional context in comments.

6 Comments

I keep coming back to this answer. I've shouted "I forgot this again?!" at least 5 times in past few months.
I cannot find that command in node_modules/.bin directory.
@zennin, if you're referring to ng serve, it's entered in terminal. Also, it's specific to angular cli. If you aren't using angular cli then you won't be able to run ng serve. More here.
@user3414799 I got this error while compiling with --aot can you please help me?
I swear, I even remember restarting it - but this was it 🤦🏼‍♂️
|
42

For newer Angular versions (10+?) lazy loading is done using the following syntax:

{ path: "foos", loadChildren: () => import ("./foos/foo.module").then(m => m.FooModule) },

I met a similar issue when working with Angular 4.4.5 and webpack and managed to fix it without using strings, but module type reference (much easier to write and less error prone):

const routes: Routes = [
  { path: '', loadChildren: () => TestModule }
];

I could not find the minimum version for Angular (loader) the supports this syntax.


A way that might work with AOT is to replace lambda syntax with a regular one:

export function getTestModule() { return TestModule; }

const routes: Routes = [
  { path: '', loadChildren: getTestModule }
];

Also check this issue (thanks to rey_coder).

8 Comments

I would prefere this solution but i does not work for me. ERROR in Error: Error encountered resolving symbol values statically. Reference to a local (non-exported) symbol 'appRoutes'. Consider exporting the symbol (position 8:7 in the original .ts file), resolving symbol AppRoutingModule
@Pascal - how is your module exported? I simply export it without default: export class TestModule { }
@Alexei How to use it, import TestModule in app.routes and then use it like loadChildren: () => TestModule ? I'm doing similarly with my app but getting above mentioned error ERROR in Error: Error encountered resolving symbol values statically. and if I do it with string I get cannot-find-module
@Sam - unfortunately, you are right. I had to use loadChildren with the path.
Thank you so much! this helped tremendously! You helped us out of a literal misery!
|
34

I have faced this same issue. I solved it by doing following 2 things:

In root module's route configuration, use loadChildren with a relative path to the lazy loaded angular module. The string is delimited with a # where the right side of split is the lazy loaded module's class name.

I have added ./ as prefix to the loadChildren string.

{ path:'user', loadChildren:'./app/user/user.module#UserModule'}

I am using webpack 2 and it needs a loader for Angular 2 that enables string-based module loading with the Angular Router. Add this to the project

yarn add angular-router-loader -D

then add the angular-router-loader to typescript loaders

loaders: [
  {
    test: /\.ts$/,
    loaders: [
    'awesome-typescript-loader',
    'angular-router-loader'
    ]
  }
]

and its working for me.

3 Comments

I had to omit the app part also: { path:'user', loadChildren:'./user/user.module#UserModule'}
@Jasnan where to add this loaders, I don't know which file it is
@NikhilRadadiya loaders are in webpack.config.js file. But if you're using angular-cli you won't have this file unless you will use ng eject, but it's not recommended in projects build with angular-cli
19

For people who are using a recent Angular version (v9 in my case), you can setup your route with the following syntax declaration:

import { TestModule } from './modules/test.module';
const appRoutes: Routes = [
  { path: 'blogs', loadChildren: () => import('./modules/test.module').then(m => m.TestModule) },
];

// NgModule
// declarations
// imports
// providers
// bootstrap

export class AppModule { }

Another way (without making the import at the top):

    const appRoutes: Routes = [
      { path: 'blogs', loadChildren: () => import('./modules/test.module').then(m => m.TestModule) },
    ];

3 Comments

the first way, is it really needed? seems to me that TestMudule is never used... the import that's working is the one in () => import
This of all the answers have solved my problem, not the ng serve restart nor the relative paths. Upvoting so this would come top as accepted answer.
In Angular 9 this solved my problem! I used the second version without the import at the top. Thanks so much for sharing!
12

Finally I found out that I need to import lazy loaded module in routing config this way:

const routes: Routes = [
   { path: '', loadChildren: 'app/test.module' }
];

without any / or ./in front of module path.

4 Comments

Actually both are valid, you also need to keep the path like that + restart ng serve
This answer worked for me. But not the restart ng-serve answer.
I found the exact opposite to be true, ./ worked for me not app
Removing ./ and adding app/ worked for me on an Angular CLI project.
4

In Angular 9 I did this and it worked for me: loadChildren: () => import('./items/items.module').then(m => m.ItemsModule)

You can have a look on official documentation

Comments

3

I change this

{
            path: 'test',
            loadChildren: 'app/tests/test.module#TestModule'

}

for this

   {
        path: 'test', loadChildren: () => new Promise(resolve => {
            (require as any).ensure([], require => {
                resolve(require('app/tests/test.module').TestModule);
            })
        })
    },

And solved my problem.

1 Comment

thanks! this was the only thing that worked for me!
3

It was worked for me by using.

../app/

I solved this issue by using the suggestion popup in VS code. You can also follow that. No need to go anywhere. (I Think, the path may vary in every project.)

Comments

2

I've been troubleshooting this for a a couple of hours on a project I've just taken over from. None of the above solutions were working, but then I realised that all the lazy-loaded modules had the .ts extension.

If anyone else is having issues, check if you need to change loadChildren: 'app/example.module.ts' to loadChildren: 'app/example.module'.

Comments

1

In a use-case scenario to segregate a distinct feature (e.g. test.module.ts) from its root application (i.e. app.module.ts) through a lazily-loaded module, we could create the test module and it's components in a sub-folder (e.g. src/app/test/). The test-routing.module could be configured this way:

//test-routing.module.ts
//routes to test.component.ts as an example

import { Routes, RouterModule } from '@angular/router';
import { TestComponent } from './test.component';

const feature_test_routes: Routes = [

    { 
        path: '',
        component: TestComponent
    }

];

export const TestRoutingModule = RouterModule.forChild(feature_test_routes);

The "parent" module (app-routing.module.ts), would have a route that looks like this:

//app-routing.module.ts
//routes to http://localhost:4200/test

import { Routes, RouterModule } from '@angular/router';
import { AppComponent } from './app.component';
const root_routes: Routes = [

    { 
        path: '',
        component: AppComponent, 
        children: [
            {
                path: 'test',
                loadChildren: './test/test.module#TestModule'
            }
        ]
    }

];

export const AppRoutingModule = RouterModule.forChild(root_routes);

This allows the root application and entry component, imperatively loaded, to subsequently lazy-load features from test.module.ts as a child when needed.

Comments

1

make sure to include import { Routes, RouterModule } from '@angular/router'; in the module to load lazely

Comments

1

I had a similar issue. I just restarted the server and it worked. :)

Comments

1

I have solved my own issue. Don't put the .ts in the path name. Rather than using 'path/to/my/module.ts#MyModuleClass', use 'path/to/my/module#MyModuleClass'

Comments

1

In my case the path shared the same route as one I declared elsewhere, assuming they would be relative paths. e.g like below in the

Not Working

Admin Module

    {
    path: 'organisation',
    canActivate: [AuthGuard],
      loadChildren: './organisation/organisation.module#AdminOrganisationModule',
    },

User Module

    {
    path: 'organisation',
    canActivate: [AuthGuard],
      loadChildren: './organisation/organisation.module#UserOrganisationModule',
    },

individually, when only one was declared, these were working fine, but not together as it complained about the ./organisation/organisation.module path , I changed both to the pattern below and it was ok.

Working

Admin Module

    {
    path: 'organisation',
    canActivate: [AuthGuard],
      loadChildren: '../admin/organisation/organisation.module#AdminOrganisationModule',
    },

User Module

        {
    path: 'organisation',
    canActivate: [AuthGuard],
      loadChildren: '../user/organisation/organisation.module#UserOrganisationModule',
    },

Comments

0

You need to change

export default class TestModule { }

to

export class TestModule { }

That should fix your problems

Comments

0

in my project i resolved the issue by changing the relative path to start from src

so instead of

loadChildren: () => import('./user/user.module') .then(m => m.UserModule)

I changed to:

loadChildren: () => import('./src/app/user/user.module') .then(m => m.UserModule)

Folder structure was: enter image description here

Comments

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