Make the gem

Rakefile

@@ -3,7 +3,6 @@ require "rake/testtask"
 require "standard/rake"
 
 Rake::TestTask.new(:test) do |t|
-  t.warning = false
   t.libs << "test"
   t.libs << "lib"
   t.test_files = FileList["test/**/*_test.rb"]

lib/todo_or_die.rb

@@ -1,19 +1,31 @@
-require "date"
-
 require "todo_or_die/version"
 require "todo_or_die/overdue_error"
 
 # The namespace
 module TodoOrDie
+  DEFAULT_CONFIG = {
+    die: ->(message, due_at) {
+      raise TodoOrDie::OverdueTodo.new <<~MSG
+        TODO: "#{message}" came due on #{due_at.strftime("%Y-%m-%d")}. Do it!
+      MSG
+    },
+  }.freeze
+
+  def self.config(options = {})
+    @config ||= reset
+    @config.merge!(options)
+  end
+
+  def self.reset
+    @config = DEFAULT_CONFIG.dup
+  end
 end
 
 # The main event
 def TodoOrDie(message, by:) # rubocop:disable Naming/MethodName
   due_at = by.to_time
 
   if Time.now >= due_at
-    raise TodoOrDie::OverdueTodo.new <<~MSG
-      TODO: "#{message}" came due on #{due_at.strftime("%Y-%m-%d")}. Do it!
-    MSG
+    TodoOrDie.config[:die].call(message, due_at)
   end
 end

test/test_helper.rb

@@ -6,5 +6,6 @@
 class UnitTest < Minitest::Test
   def teardown
     Timecop.return
+    TodoOrDie.reset
   end
 end

test/todo_or_die_test.rb

@@ -20,4 +20,39 @@ def test_due_todo_blows_up
       TODO: "Fix stuff" came due on 2200-02-04. Do it!
     MSG
   end
+
+  def test_config_custom_explosion
+    Timecop.travel(Date.civil(2200, 2, 5))
+    actual_message, actual_by = nil
+    TodoOrDie.config(
+      die: ->(message, by) {
+        actual_message = message
+        actual_by = by
+        "pants"
+      }
+    )
+    some_time = Time.parse("2200-02-04")
+
+    result = TodoOrDie("kaka", by: some_time)
+
+    assert_equal result, "pants"
+    assert_equal actual_message, "kaka"
+    assert_same actual_by, some_time
+  end
+
+  def test_config_and_reset
+    some_lambda = -> {}
+    TodoOrDie.config(die: some_lambda)
+
+    assert_equal TodoOrDie.config[:die], some_lambda
+    assert_equal TodoOrDie.config({})[:die], some_lambda
+
+    TodoOrDie.reset
+
+    assert_equal TodoOrDie.config[:die], TodoOrDie::DEFAULT_CONFIG[:die]
+  end
+
+  def test_has_version
+    assert TodoOrDie::VERSION
+  end
 end