JonathanBechtel JonathanBechtel - 1 year ago 331
TypeScript Question

Cannot find module './in-memory-data-service' in tour of heroes for Angular2

I am trying to work through the Angular2 tour of heroes app, and am running into bugs on the Http section of the tutorial.

At first I was getting the error:

Cannot find module 'angular2-in-memory-web-api'

But fixed that using the information from this question.

However, at this same step I'm also getting the following error:

app/app.module.ts(10,38): error TS2307: Cannot find module './in-memory-data-service'.

I've triple checked and I believe both my in-memory-data-service.ts file and my app.module.ts file are exactly the same as listed in the tutorial (at this particular point in time).

Right now my in-memory-data-service.ts file looks like this:


import { InMemoryDbService } from 'angular2-in-memory-web-api';
export class InMemoryDataService implements InMemoryDbService {
createDb() {
let heroes = [
{id: 11, name: 'Mr. Nice'},
{id: 12, name: 'Narco'},
{id: 13, name: 'Bombasto'},
{id: 14, name: 'Celeritas'},
{id: 15, name: 'Magneta'},
{id: 16, name: 'RubberMan'},
{id: 17, name: 'Dynama'},
{id: 18, name: 'Dr IQ'},
{id: 19, name: 'Magma'},
{id: 20, name: 'Tornado'}
return {heroes};

My app.module.ts file looks like this:


import './rxjs-extensions';

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

//Imports for loading & configuring the in-memory web API
import { InMemoryWebApiModule } from 'angular2-in-memory-web-api';
import { InMemoryDataService } from './in-memory-data-service';

import { AppComponent } from './app.component';
import { DashboardComponent } from './dashboard.component';
import { HeroesComponent } from './heroes.component';
import { HeroDetailComponent } from './hero-detail.component';
import { HeroService } from './hero.service';
import { routing } from './app.routing';

imports: [
declarations: [
providers: [
bootstrap: [ AppComponent ]

export class AppModule {

I'm not sure if this is due to some sort of dependency in package.json or systemjs.config that's not set appropriately, or if there's a simple mistake I'm helping.


My systemjs.config.js file looks like this:


(function (global) {
paths: {
// paths serve as alias
'npm:': 'node_modules/'
// map tells the System loader where to look for things
map: {
// our app is within the app folder
app: 'app',
// angular bundles
'@angular/core': 'npm:@angular/core/bundles/core.umd.js',
'@angular/common': 'npm:@angular/common/bundles/common.umd.js',
'@angular/compiler': 'npm:@angular/compiler/bundles/compiler.umd.js',
'@angular/platform-browser': 'npm:@angular/platform-browser/bundles/platform-browser.umd.js',
'@angular/platform-browser-dynamic': 'npm:@angular/platform-browser-dynamic/bundles/platform-browser-dynamic.umd.js',
'@angular/http': 'npm:@angular/http/bundles/http.umd.js',
'@angular/router': 'npm:@angular/router/bundles/router.umd.js',
'@angular/forms': 'npm:@angular/forms/bundles/forms.umd.js',
// other libraries
'rxjs': 'npm:rxjs',
'angular2-in-memory-web-api': 'npm:angular2-in-memory-web-api',
// packages tells the System loader how to load when no filename and/or no extension
packages: {
app: {
main: './main.js',
defaultExtension: 'js'
rxjs: {
defaultExtension: 'js'
'angular2-in-memory-web-api': {
main: 'index.js',
defaultExtension: 'js'

My file structure currently looks like this:

File Structure:



Thank you.

Answer Source

Just make sure all your bases are covered

In your package.json, should match the one on this page.

"angular-in-memory-web-api": "~0.1.1",

Also, your systemjs.config file looks good too!

In your app.module.ts, make sure that your in-memory-data-service import matches your file because in their example they have in-memory-data.service

// Imports for loading & configuring the in-memory web api
import { InMemoryWebApiModule } from 'angular-in-memory-web-api';
import { InMemoryDataService }  from './in-memory-data-service'; // <-- Make sure this matches the file name

So your file should be named in-memory-data-service.ts. It looks like to me that there is a naming typo or some sort of file structure issue.

It looks like you solved the package.json issue, and the error that you are getting is saying that it can't find that module, now that could be because you have a typo in the name of the file or the path to the file is wrong in the import line.

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