This commit introduces a new `HttpBackend` implentation which makes requests using the fetch API
This feature is a developer preview and is opt-in.
It is enabled by setting the providers with `provideHttpClient(withFetch())`.
NB: The fetch API is experimental on Node but available without flags from Node 18 onwards.
PR Close#50247
Some libraries could use numbers in headers. this fix prevents Angular from
throwing an error by casting those numerical values into strings.
Fixes#49353
PR Close#49379
All errors for existing fields have been detected and suppressed with a
`!` assertion.
Issue/24571 is tracking proper clean up of those instances.
One-line change required in ivy/compilation.ts, because it appears that
the new syntax causes tsickle emitted node to no longer track their
original sourceFiles.
PR Close#24572
HttpClient is an evolution of the existing Angular HTTP API, which exists
alongside of it in a separate package, @angular/common/http. This structure
ensures that existing codebases can slowly migrate to the new API.
The new API improves significantly on the ergonomics and features of the legacy
API. A partial list of new features includes:
* Typed, synchronous response body access, including support for JSON body types
* JSON is an assumed default and no longer needs to be explicitly parsed
* Interceptors allow middleware logic to be inserted into the pipeline
* Immutable request/response objects
* Progress events for both request upload and response download
* Post-request verification & flush based testing framework
