[WIP] Add recipe for hot observables

docs/recipes/hot-observables.md

@@ -0,0 +1,52 @@
+# How to test hot observables
+
+Ava supports autosubscribing to cold observables, which will not work for hot observables.
+For hot observables, we will need to first subscribe, and then trigger the values to be sent in the stream.
+We can automatically unsubscribe by using `#take()`.
+
+## Installing rxjs v5
+`npm install --save rxjs`
+
+## Create a source file named interactions.js
+
+```
+function create({Rx}) {
+  const writeSubject = new Rx.Subject()
+
+  function write(data) {
+    writeSubject.next(data)
+  }
+
+  return {
+    actions: {write},
+    events: {write: writeSubject.toObservable()}
+  }
+}
+
+export default {
+  create
+}
+```
+
+## Now test it
+
+```
+import tests from 'Ava'
+import Rx from 'rxjs'
+import interactionsFactory from './interactions'
+
+tests(
+  `Given that we subscribe to the write event,
+  when  the user calls the action write with 'hello'
+  then our subscriber recieves the message 'hello'`,
+  function onTest(test) {
+    const expected = 'hello'
+    const interactions = interactionsFactory.create({Rx})
+    interactions.events.write.take(1).subscribe(function(actual) {
+      test.is(actual, expected)
+      test.done()
+    })
+    interactions.actions.write(expected)
+  }
+)
+```