Remove assertions on errors

lib/blank_assertions.ex

@@ -39,10 +39,6 @@ defmodule BlankAssertions do
     end
   end
 
-  def assert_raise(exception, callback) do
-    ExUnit.Assertions.assert_raise exception, fn -> callback.call() end
-  end
-
   def assert(value, opts) do
     ExUnit.Assertions.assert(value, opts)
   end

lib/koans/12_tuples.ex

@@ -21,10 +21,6 @@ defmodule Tuples do
     assert Tuple.insert_at({:a, "hi"}, 1, :new_thing) == :__
   end
 
-  koan "...avoid falling of the edge" do
-    assert_raise :__, fn ->  Tuple.insert_at({:a, "hi"}, 12, :new_thing) end
-  end
-
   koan "add things at the end" do
     assert Tuple.append({"Huey", "Dewey"}, "Louie") == :__
   end
@@ -33,10 +29,6 @@ defmodule Tuples do
     assert Tuple.delete_at({:this, :is, :not, :awesome}, 2) == :__
   end
 
-  koan "you can't delete what you don't have" do
-    assert_raise :__, fn ->  Tuple.delete_at({:a, "hi"}, 12) end
-  end
-
   koan "turn it into a list in case you need it" do
     assert Tuple.to_list({:this, :can, :be, :a, :list}) == :__
   end

test/koans_harness_test.exs

@@ -224,10 +224,8 @@ defmodule KoansHarnessTest do
       "hi",
       {:a, "bye"},
       {:a, :new_thing, "hi"},
-      ArgumentError,
       {"Huey", "Dewey", "Louie"},
       {:this, :is, :awesome},
-      ArgumentError,
       [:this, :can, :be, :a, :list]
     ]