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

Question

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:

CODE:

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:

CODE:

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';

@NgModule({
  imports:        [
                    BrowserModule,
                    FormsModule,
                    HttpModule,
                    InMemoryWebApiModule.forRoot(InMemoryDataService),
                    routing
                  ],
  declarations:   [
                    AppComponent,
                    DashboardComponent,
                    HeroDetailComponent,
                    HeroesComponent
                  ],
  providers:      [
                    HeroService
                  ],
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.

EDIT

My systemjs.config.js file looks like this:

CODE:

(function (global) {
System.config({
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'
  }
}
});
})(this);

My file structure currently looks like this:

File Structure:

app/app.module.ts
app/in-memory-data-service.ts

index.html
systemjs.config.js

Thank you.

Answer 1

ng generate service InMemoryData --module=app

Will create the src/app/in-memory-data.service.ts file. Then add the code listed in the tutorial and it will work. AFAIK they don't even imply that in the tutorial so don't feel bad. In fact what they say is

The forRoot() configuration method takes an InMemoryDataService class that primes the in-memory database.

The Tour of Heroes sample creates such a class src/app/in-memory-data.service.ts

Which is gibberish and wrong.

Answer 2

My projects created using current CLI Tools, and I installed this:

npm install angular-in-memory-web-api --save

It works for me.

Answer 3

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.