When using `withFetch`, the `PRIMARY_HTTP_BACKEND` token is set.
The InMemory Backend services will also set that token.
This means that providers order will matter and the latest on the list will be the one instantiated
PR Close#52425
In combination with the TS `noImplicitOverride` compatibility changes,
we also want to follow the best-practice of adding `override` to
members which are implemented as part of abstract classes. This
commit fixes all instances which will be flagged as part of the
custom `no-implicit-override-abstract` TSLint rule.
PR Close#42512
With this change we move `XhrFactory` to the root entrypoint of `@angular/commmon`, this is needed so that we can configure `XhrFactory` DI token at a platform level, and not add a dependency between `@angular/platform-browser` and `@angular/common/http`.
Currently, when using `HttpClientModule` in a child module on the server, `ReferenceError: XMLHttpRequest is not defined` is being thrown because the child module has its own Injector and causes `XhrFactory` provider to be configured to use `BrowserXhr`.
Therefore, we should configure the `XhrFactory` at a platform level similar to other Browser specific providers.
BREAKING CHANGE:
`XhrFactory` has been moved from `@angular/common/http` to `@angular/common`.
**Before**
```ts
import {XhrFactory} from '@angular/common/http';
```
**After**
```ts
import {XhrFactory} from '@angular/common';
```
Closes#41311
PR Close#41313
