constructor coverage for angular is not correct anymore

[bulldog98]

Current Behavior

If you have an angular lib/app with an injection in the constructor then jest reports it as a not covered branch

Expected Behavior

This is a regression I remember it working around 1-2 weeks ago (was 14.6.5 I think).

Steps to Reproduce

Reproduction: nrwl/nx-examples#229

• run yarn nx products:test
• observe the coverage info

[Blackbaud-SteveBrush]

I'm seeing this too.
I'm on Nx version 14.7.13.
Coverage is correct when using @angular/compiler-cli@14.2.0, but coverage drops (constructor, specifically) when I update to @angular/compiler-cli@^14.2.1. Any ideas?

[abaran30]

We're also experiencing this issue with Nx 14.8.0. Downgrading @angular/compiler-cli does not change anything for us, unfortunately.

[abaran30]

Update: in our case, downgrading jest-preset-angular from 12.2.2 to 12.2.0 resulted in the following behaviors (12.1.0 is not usable):

• constructor params (dependency injection) are no longer marked as branches for coverage
• Code coverage is not collected from all files (perhaps fixed in 12.2.2)
• Not all tests are able to run, as some result in errors like the following (perhaps also fixed in 12.2.2):

    Component 'AppComponent' is not resolved:
     - templateUrl: ./app.component.html
     - styleUrls: ["./app.component.scss"]
    Did you run and wait for 'resolveComponentResources()'?

Going to look deeper into jest-preset-angular to see why this might be the case.

Edit: [Bug]: 12.2.2 breaks branch coverage

[Blackbaud-SteveBrush]

I'll add that we're using Karma as our test runner. Unsure why downgrading @angular/compiler-cli works in our case.

[willyboy]

Removing emitDecoratorMetadata from tsconfig.base.json did it for me - I also removed some hardcoded istanbul/karma/jasmine deps

[abaran30]

Removing emitDecoratorMetadata from tsconfig.base.json also works for us as a workaround for this issue (hesitant to call this a fix).

[Blackbaud-SteveBrush]

According to this article, it appears Angular 12+ no longer requires emitDecoratorMetadata to be set. 🤷‍♂️

The TS option emitDecoratorMetadata is no longer needed by Angular, and can be safely removed from tsconfig.json.

[Blackbaud-SteveBrush]

The problem with disabling emitDecoratorMetadata, however, is that /* istanbul ignore next */ on decoratored functions no longer works.

[Blackbaud-SteveBrush]

FYI, to reproduce the issue, run the following:

npx create-nx-workspace@15.1.1 --ci=github --nxCoud=true --preset=angular
npx nx g @nrwl/angular:lib ui --publishable --importPath=@skyux/ui --unitTestRunner=karma
npx nx g component todos --project=ui --export    

Add an injectable to the component's constructor (anything, really). For example:

  constructor(title: Title) {
    title.setTitle('foobar');
  }

Then, run the tests:

npx nx test ui --code-coverage   

You'll see the Branches coverage is at 75%, but when you look at the coverage report, it's highlighting something incorrectly.

[dolphinigle]

Can confirm this issue still exists in 15.2.4. Removing emitDecoratorMetadata everywhere in our code fixes this.