IEx - run Mix "test" task

I get a bit tired of switching between Tmux panes so I'm trying to just work with vim and iex rather than entering mix commands into another console.

With that goal in mind, I enter the following into the iex console but my tests don't appear to execute:

Mix.env(:test)
Mix.Task.reenable "test"
Mix.Task.run "test", []

The console output is:

iex(52)>Mix.env(:test)
:ok
iex(53)>Mix.Task.reenable "test"
:ok
iex(54)>Mix.Task.run "test", []


Finished in 0.00 seconds
0 tests, 0 failures

Randomized with seed 732638
[#Function<4.72894143/1 in http://ift.tt/222UERS;,
 #Function<4.72894143/1 in http://ift.tt/222UERS;,
 #Function<4.72894143/1 in http://ift.tt/222UERS;,
 #Function<4.72894143/1 in http://ift.tt/222UERS;,
 #Function<4.72894143/1 in http://ift.tt/222UERS;,
 #Function<4.72894143/1 in http://ift.tt/222UERS;,
 #Function<4.72894143/1 in http://ift.tt/222UERS;,
 #Function<4.72894143/1 in http://ift.tt/222UERS;,
 #Function<4.72894143/1 in http://ift.tt/222UERS;,
 #Function<4.72894143/1 in http://ift.tt/222UERS;,
 #Function<4.72894143/1 in http://ift.tt/222UERS;,
 #Function<4.72894143/1 in http://ift.tt/222UERS;]

Can anyone give me a pointer on how to make this work?