Can't resolve all parameters for AppComponent

Question

i'm building big project, this is started part of it. my problem is very common, however I did not find a way to solve it. really need your help! I get an error of type. I will be glad to any help

Uncaught Error: Can't resolve all parameters for AppComponent: (?).
at syntaxError (main-client.js:52112)
at CompileMetadataResolver._getDependenciesMetadata (main-client.js:67193)
at CompileMetadataResolver._getTypeMetadata (main-client.js:67028)
at CompileMetadataResolver.getNonNormalizedDirectiveMetadata (main-client.js:66536)
at CompileMetadataResolver._getEntryComponentMetadata (main-client.js:67341)
at main-client.js:66822
at Array.map (<anonymous>)
at CompileMetadataResolver.getNgModuleMetadata (main-client.js:66822)
at CompileMetadataResolver.getNgModuleSummary (main-client.js:66645)
at main-client.js:66733
at Array.forEach (<anonymous>)
at CompileMetadataResolver.getNgModuleMetadata (main-client.js:66718)
at JitCompiler._loadModules (main-client.js:85147)
at JitCompiler._compileModuleAndComponents (main-client.js:85108)
at JitCompiler.compileModuleAsync (main-client.js:85024)
at CompilerImpl.compileModuleAsync (main-client.js:50948)
at PlatformRef.bootstrapModule (main-client.js:6395)
at Object.defineProperty.value (main-client.js:49385)
at __webpack_require__ (main-client.js:679)
at fn (main-client.js:89)
at Object.options.path (main-client.js:48085)
at __webpack_require__ (main-client.js:679)
at module.exports (main-client.js:725)
at main-client.js:728

Here is my app.module.shared.ts

    import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { FormsModule, ReactiveFormsModule } from '@angular/forms';
import { TranslateModule, TranslateLoader } from '@ngx-translate/core';
import { TranslateHttpLoader } from '@ngx-translate/http-loader';

import { AppComponent } from './app.component';
import { AppService } from './app.service'
import { HttpClient, HttpClientModule } from '@angular/common/http';
export function HttpLoaderFactory(http: HttpClient) {
    return new TranslateHttpLoader(http,
    ((typeof window !== 'undefined') ? window.location.origin: "http://localhost:5000")
        +'/assets/i18n/', '.json');
}

@NgModule({
declarations: [
    AppComponent,
],
imports: [
    HttpClientModule,
    FormsModule,
    ReactiveFormsModule,
    TranslateModule.forRoot({
    loader: {
        provide: TranslateLoader,
        useFactory: HttpLoaderFactory,
        deps: [HttpClient]
    }
    }),
    BrowserModule    
],
providers: [AppService],
bootstrap: [AppComponent]
})

export class AppModuleShared {
}

Here is my app.component.ts

import { Component } from '@angular/core';
import { AppService } from '@app/app.service';

@Component({
    selector: 'app-root',
    templateUrl: './app.component.html',
    styleUrls: ['./app.component.css']
})
export class AppComponent {
    constructor(service: AppService) { }
}

Here is my app.component.html

<p>WORK</p>

Here is my app.service.ts

import { Injectable } from '@angular/core';
@Injectable()
export class AppService { }

Here is my package.json

    {
    "name": "new_ang",
    "private": true,
    "version": "0.0.0",
    "scripts": {
        "test": "karma start ClientApp/test/karma.conf.js"
    },
    "dependencies": {
        "@angular/animations": "5.0.2",
        "@angular/common": "5.0.2",
        "@angular/compiler": "5.0.2",
        "@angular/compiler-cli": "5.0.2",
        "@angular/core": "5.0.2",
        "@angular/forms": "5.0.2",
        "@angular/http": "5.0.2",
        "@angular/platform-browser": "5.0.2",
        "@angular/platform-browser-dynamic": "5.0.2",
        "@angular/platform-server": "5.0.2",
        "@angular/router": "5.0.2",
        "@aspnet/signalr-client": "1.0.0-alpha2-final",
        "@ng-bootstrap/ng-bootstrap": "1.0.0-beta.5",
        "@nguniversal/aspnetcore-engine": "^5.0.0-beta.5",
        "@ngx-translate/core": "8.0.0",
        "@ngx-translate/http-loader": "^2.0.0",
        "@types/webpack-env": "^1.13.2",
        "angular": "^1.6.6",
        "angular-oauth2-oidc": "3.0.2",
        "angular2-jwt": "0.2.3",
        "aspnet-prerendering": "3.0.1",
        "aspnet-webpack": "2.0.1",
        "bootstrap": "4.0.0-beta.2",
        "core-js": "2.5.1",
        "font-awesome": "4.7.0",
        "isomorphic-fetch": "2.2.1",
        "msgpack5": "3.6.0",
        "ng2-charts": "^1.6.0",
        "ng2-tree": "^2.0.0-rc.2",
        "ngx-swiper-wrapper": "^5.0.2",
        "preboot": "5.1.7",
        "rxjs": "5.5.2",
        "zone.js": "0.8.18"
    },
    "devDependencies": {
        "@angular/cli": "1.5.2",
        "@angular/compiler-cli": "5.0.2",
        "@compodoc/compodoc": "1.0.4",
        "@ngtools/webpack": "1.8.2",
        "@types/hammerjs": "2.0.35",
        "@types/jasmine": "2.6.3",
        "@types/node": "8.0.51",
        "@types/selenium-webdriver": "3.0.8",
        "@types/source-map": "0.5.2",
        "@types/uglify-js": "2.6.29",
        "@types/webpack": "3.8.1",
        "angular-router-loader": "^0.8.0",
        "angular2-template-loader": "0.6.2",
        "awesome-typescript-loader": "3.3.0",
        "codelyzer": "4.0.1",
        "css-loader": "0.28.7",
        "extract-text-webpack-plugin": "3.0.2",
        "file-loader": "1.1.5",
        "html-loader": "0.5.1",
        "html-webpack-plugin": "2.30.1",
        "istanbul-instrumenter-loader": "3.0.0",
        "karma": "1.7.1",
        "karma-chrome-launcher": "2.2.0",
        "karma-coverage": "1.1.1",
        "karma-coverage-istanbul-reporter": "1.3.0",
        "karma-jasmine": "1.1.0",
        "karma-jasmine-html-reporter": "0.2.2",
        "karma-mocha-reporter": "2.2.5",
        "karma-remap-coverage": "0.1.4",
        "karma-sourcemap-loader": "0.3.7",
        "karma-webpack": "2.0.6",
        "ng-router-loader": "2.1.0",
        "node-sass": "4.7.1",
        "protractor": "5.2.0",
        "raw-loader": "0.5.1",
        "sass-loader": "6.0.6",
        "source-map-loader": "0.2.3",
        "style-loader": "0.19.0",
        "to-string-loader": "1.1.5",
        "ts-node": "3.3.0",
        "tslib": "1.8.0",
        "tslint": "5.8.0",
        "typescript": "2.6.1",
        "uglifyjs-webpack-plugin": "1.0.1",
        "url-loader": "0.6.2",
        "webpack": "3.8.1",
        "webpack-bundle-analyzer": "2.9.1",
        "webpack-hot-middleware": "2.20.0",
        "webpack-merge": "4.1.1"
    }
}

Environment

Angular CLI: 1.5.2
Node: 8.3.0
OS: linux x64
Angular: 5.0.2

Nicolle

is that all the code of AppService? Does this service has dependencies injected in its constructor? – Graphy

@Graphy AppService is absolutely empty and doesn't containt any code inside, thats all he has – Nicolle

Would you mind putting BrowserModule at the top of your imports and check if that makes a difference? – Graphy

@Graphy ofc, i did, but result is the same – Nicolle

Answer 1

Problem was solved by adding Inject directive to Service in AppComponent

constructor(@Inject(AppService) service: AppService)

Nicolle

This works for me. Without Inject, the app is working fine. However, with ng test, it seems Inject is required. I am using Angular 6 – Ozuna

Exactly the same situation in Angular 7: https://mcmap.net/q/752979/-angular-unit-testing-a-component-that-creates-a-service-via-an-interface/220545 – Blackburn

Answer 2

After 1 day on this I realized I had removed some polyfills I didn't think I needed.

This is what I was missing:

import 'core-js/es7/reflect';

See https://github.com/angular/angular/issues/19417#issuecomment-359722822 for more info.

Harebell

Answer 3

Try to put semicolon after this line in your app.module.shared.ts:

import { AppService } from './app.service' 

we can get this error for various reasons like: Syntax error, duplicate comma, or missing a semicolon

Bushwhack

hello @Aakriti , thanx for reply, i put semicolon , but the result is the same – Nicolle

Answer 4

Your service should be refered from a relative path as below,

I think you need

import { AppService } from '.app/app.service';

instead of

import { AppService } from '@app/app.service';

Cot

,thanks for reply, i think you're missing / (slash) before .(dot) :) but not, this option did not help – Nicolle

Answer 5

Please make sure that you have 'emitDecoratorMetadata' set to true as below in tsconfig.js

{
  "compileOnSave": false,
  "compilerOptions": {
    "emitDecoratorMetadata": true
  }
}

This will resolve your issue.

Servitude

Answer 6

In my case I was trying to use:

constructor(private location: Location) { }

But you have to be aware there's an interface and there's a library with the same name. The interface was my problem since I needed the library, so I chose carefully again among the options and picked the library wich automatically added:

import { Location } from '@angular/common';

And problem solved....

Anisomerous

Answer 7

try this one. it works for me, seems polyfill problem.

<script src="node_modules/core-js/client/shim.min.js"></script> https://github.com/angular/angular/issues/19417

Icj

It would be helpful if you provide more information on your solution – Tybi

use npm install core-js and include shim.min.js file in browser – Icj

Answer 8

I have resolved this bug, import 'core-js', before all modules. However, I had a Hybrid app;

Disassociate