run commands using default.nix file

Question

I've got the following default.nix file:

with import <nixpkgs> {}; {
   pullapiEnv = stdenv.mkDerivation {
     name = "pullapi";
     buildInputs = [ elixir ];
   };
 }

Which is great, and works with nix-shell inside my repo, however how do run I commands during the shell setup? I'd like to run

mix deps.get
mix test

upon each nix-shell execution.

Answer 1

As per wizzup's comment, this was solved using shellHook:

#default.nix
with import <nixpkgs> {}; {
   pullapiEnv = stdenv.mkDerivation {
     name = "pullapi";
     buildInputs = [ elixir ];
     shellHook = ''
     mix deps.get
     mix compile
     mix test
     '';
   };
}