Angular CLI - ng test Command


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This chapter explains the syntax, argument and options of ng test command along with an example.

Syntax

The syntax for ng test command is as follows −

ng test <project> [options]
ng t <project> [options]

ng test run the unit test cases on angular app code.

Arguments

The argument for ng test command is as follows −

Sr.No. Argument & Syntax Description
1 <project> The name of the project to test.

Options

Options are optional parameters.

Sr.No. Option & Syntax Description
1 --browsers=browsers Override which browsers tests are run against.
2 --codeCoverage=true|false

Output a code coverage report.

Default: false

3 --codeCoverageExclude Globs to exclude from code coverage.
4 --configuration=configuration

A named build target, as specified in the "configurations" section of angular.json. Each named target is accompanied by a configuration of option defaults for that target. Setting this explicitly overrides the "--prod" flag

Aliases: -c

5 --help=true|false|json|JSON

Shows a help message for this command in the console.

Default: false

6 --include

Globs of files to include, relative to workspace or project root. There are 2 special cases −

  • when a path to directory is provided, all spec files ending ".spec.@(ts|tsx)" will be included.

  • when a path to a file is provided, and a matching spec file exists it will be included instead.

7 --karmaConfig=karmaConfig The name of the Karma configuration file.
8 --main=main The name of the main entry-point file.
9 --poll Enable and define the file watching poll time period in milliseconds.
10 --polyfills=polyfills The name of the polyfills file.
11 --preserveSymlinks=true|false

Do not use the real path when resolving modules.

Default: false

12 --prod=true|false Shorthand for "--configuration=production". When true, sets the build configuration to the production target. By default, the production target is set up in the workspace configuration such that all builds make use of bundling, limited tree-shaking, and also limited dead code elimination.
13 --progress=true|false Log progress to the console while building.
13 --progress=true|false Log progress to the console while building.
14 --reporters Karma reporters to use. Directly passed to the karma runner.
15 --sourceMap=true|false

Output sourcemaps.

Default: true

16 --tsConfig=tsConfig The name of the TypeScript configuration file.
17 --watch=true|false Run build when files change.
18 --webWorkerTsConfig=webWorkerTsConfig TypeScript configuration for Web Worker modules.

First move to an angular project updated using ng build command.The link for this chapter is https://www.tutorialspoint.com/angular_cli/angular_cli_ng_build.htm.

Now run the test command.

Example

An example for ng test command is given below −

\>Node\>TutorialsPoint> ng test
...
WARN: ''app-goals' is not a known element:
1. If 'app-goals' is an Angular component, then verify that it is part of this module.
2. If 'app-goals' is a Web Component then add 'CUSTOM_ELEMENTS_SCHEMA' to the '@NgModule.schemas' of this component to suppress this message.'
Chrome 83.0.4103 (Windows 7.0.0): Executed 0 of 4 SUCCESS (0 secs / 0 secs)
...
AppComponent should render title FAILED
   TypeError: Cannot read property 'textContent' of null
      at <Jasmine>
      at UserContext.<anonymous> (http://localhost:9876/_karma_webpack_/src/app/app.component.spec.ts:33:51)
            ...
Chrome 83.0.4103 (Windows 7.0.0): Executed 1 of 4 (1 FAILED) (0 secs / 0.203 secs)
...
Chrome 83.0.4103 (Windows 7.0.0): Executed 2 of 4 (1 FAILED) (0 secs / 0.221 secs)
...
Chrome 83.0.4103 (Windows 7.0.0): Executed 4 of 4 (1 FAILED) (0 secs / 0.244 sec
Chrome 83.0.4103 (Windows 7.0.0): Executed 4 of 4 (1 FAILED) (0.282 secs / 0.244
 secs)
TOTAL: 1 FAILED, 3 SUCCESS

Now to fix failures update the app.component.spec.ts

app.component.spec.ts

import { TestBed, async } from '@angular/core/testing';
import { RouterTestingModule } from '@angular/router/testing';
import { AppComponent } from './app.component';

describe('AppComponent', () => {
   beforeEach(async(() => {
      TestBed.configureTestingModule({
         imports: [
            RouterTestingModule
         ],
         declarations: [
            AppComponent
         ],
      }).compileComponents();
   }));

   it('should create the app', () => {
      const fixture = TestBed.createComponent(AppComponent);
      const app = fixture.componentInstance;
      expect(app).toBeTruthy();
   });
});

Now run the test command.

Example

An example is given below −

\>Node\>TutorialsPoint> ng test
...
WARN: ''app-goals' is not a known element:
1. If 'app-goals' is an Angular component, then verify that it is part of this m
odule.
2. If 'app-goals' is a Web Component then add 'CUSTOM_ELEMENTS_SCHEMA' to the '@
NgModule.schemas' of this component to suppress this message.'
Chrome 83.0.4103 (Windows 7.0.0): Executed 1 of 2 SUCCESS (0 secs / 0.053 secs)
...
Chrome 83.0.4103 (Windows 7.0.0): Executed 2 of 2 SUCCESS (0.097 secs / 0.073 se
cs)
TOTAL: 2 SUCCESS

ng test also opens the browser and displays the test status.

Unit Test
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