<p dir="auto">Right now, this is not supported, but I'm not yet sure if there's a reason behind that. TODO(julie): investigate</p>
<p dir="auto">After <a class="commit-link" data-hovercard-type="commit" data-hovercard-url="https://github.com/angular/angular/commit/a9b1270a5abea7bbbe34a9c357036a6bf3240ae4/hovercard" href="https://github.com/angular/angular/commit/a9b1270a5abea7bbbe34a9c357036a6bf3240ae4"><tt>a9b1270</tt></a> landed, http no longer imports <code class="notranslate">Observable</code> from <code class="notranslate">@reactivex</code> but rather uses one exported by <code class="notranslate">angular2/angular2</code>. This is good since it limits http dependency.</p>
<p dir="auto">Unfortunately we still got a place where Rx is dependent upon directly: in <a href="https://github.com/angular/angular/blob/f54ba3cc1bc6d8f489ff8b56d05e2f47d416c16e/modules/angular2/src/http/backends/mock_backend.ts#L8-L9">mock_backend.ts</a></p>
<p dir="auto">mock_backend imports <code class="notranslate">Subject</code> and <code class="notranslate">ReplaySubject</code>. While we re-exporting <code class="notranslate">Subject</code> on <code class="notranslate">angular2\angular2</code> this is not the case for <code class="notranslate">ReplaySubject</code>. The current situation means that we need to either bundle entire RxJS with http or approach it as an external dependency: neither of the 2 is ideal.</p>
<p dir="auto"><a class="user-mention notranslate" data-hovercard-type="user" data-hovercard-url="/users/robwormald/hovercard" data-octo-click="hovercard-link-click" data-octo-dimensions="link_type:self" href="https://github.com/robwormald">@robwormald</a> do you see any quick-wins here?</p>