Emit output before next render pass.

Fixes #54.

Author: zach-klippenstein

workflow-runtime/src/main/java/com/squareup/workflow/RenderWorkflow.kt

@@ -158,12 +158,10 @@ fun <PropsT, OutputT, RenderingT> renderWorkflowIn(
         // It might look weird to start by consuming the output before getting the rendering below,
         // but remember the first render pass already occurred above, before this coroutine was even
         // launched.
-        val output = runner.nextOutput()
+        runner.nextOutput()
+            ?.let { onOutput(it.value) }
 
-        // After receiving an output, the next render pass must be done before emitting that output,
-        // so that the workflow states appear consistent to observers of the outputs and renderings.
         renderingsAndSnapshots.value = runner.nextRendering()
-        output?.let { onOutput(it.value) }
       }
   }
 

workflow-runtime/src/test/java/com/squareup/workflow/RenderWorkflowInTest.kt

@@ -363,5 +363,9 @@ class RenderWorkflowInTest {
     assertFalse(scope.isActive)
   }
 
+  @Test fun `output is emitted before next render pass`() {
+    TODO()
+  }
+
   private class ExpectedException : RuntimeException()
 }