Summary

This patch exposes a browser client for simplifying HTTP requests. The long-term goal of this service/client is to replace the legacy kfetch service. This patch also swaps out the internals of kfetch for this new service, meaning legacy and NP plugins are both using this.

From a sat up HttpService, there are now 5 additional methods:

• http.fetch(path, options): This has an API comparable to window.fetch with the addition of a few custom options, status code error handling, default HTTP header additions, and automatic body parsing resolution for JSON and NDJSON.
• http.get(path, options): The GET-enforced shorthand for http.fetch().
• http.post(path, options): The POST-enforced shorthand for http.fetch().
• http.put(path, options): The PUT-enforced shorthand for http.fetch().
• http.delete(path, options): The DELETE-enforced shorthand for http.fetch().
• http.patch(path, options): The PATCH-enforced shorthand for http.fetch().

Fixes #18855.

Checklist

Use strikethroughs to remove checklist items you don't feel are applicable to this PR.

• This was checked for cross-browser compatibility, including a check against IE11
• Any text added follows EUI's writing guidelines, uses sentence case text and includes i18n support
• Documentation was added for features that require explanation or tutorials
• Unit or functional tests were updated or added to match the most common scenarios
• This was checked for keyboard-only and screenreader accessibility

For maintainers

• This was checked for breaking API changes and was labeled appropriately
• This includes a feature addition or change that requires a release note and was labeled appropriately

Dev Docs

The HTTP browser client now exposes methods for simplifying HTTP requests. The long-term goal of this service/client is to replace the legacy kfetch service. This also swaps out the internals of kfetch for this new service, meaning legacy and new platform plugins are both backed by this functionality.

From a sat up HttpService, there are now 5 additional methods:

• http.fetch(path, options): This has an API comparable to window.fetch with the addition of a few custom options, status code error handling, default HTTP header additions, and automatic body parsing resolution for JSON and NDJSON.
• http.get(path, options): The GET-enforced shorthand for http.fetch().
• http.post(path, options): The POST-enforced shorthand for http.fetch().
• http.put(path, options): The PUT-enforced shorthand for http.fetch().
• http.delete(path, options): The DELETE-enforced shorthand for http.fetch().
• http.patch(path, options): The PATCH-enforced shorthand for http.fetch().