Changed my mind, keeping Commander after figuring out how to fix specs.

lib/shanty/cli.rb

@@ -48,7 +48,7 @@ def setup_tasks
     def setup_task(name, task)
       command(name) do |c|
         c.description = I18n.t(task[:desc], default: task[:desc])
-        c.syntax = task[:syntax]
+        c.syntax = syntax_for_command(name, task)
         add_options_to_command(task, c)
         add_action_to_command(name, task, c)
       end
@@ -64,6 +64,7 @@ def add_action_to_command(name, task, command)
       command.action do |_, options|
         task = tasks[name]
         options.default(Hash[defaults_for_options(task)])
+        enforce_required_options(task, options)
         execute_task(name, task, options)
       end
     end
@@ -81,6 +82,14 @@ def defaults_for_options(task)
       end
     end
 
+    def syntax_for_command(name, task)
+      option_syntax = task[:options].map do |option_name, option|
+        syntax_for_option(option_name, option)
+      end
+
+      [name, *option_syntax].join(' ')
+    end
+
     def syntax_for_option(name, option)
       required = option[:required]
       case option[:type]
@@ -99,5 +108,13 @@ def default_for_type(option)
         option[:default]
       end
     end
+
+    def enforce_required_options(task, options)
+      missing = task[:options].keep_if do |option_name, option|
+        option[:required] && options.send(option_name).nil?
+      end.keys.join(', ')
+
+      abort("missing required params: #{missing}. Use --help for more information.") unless missing.empty?
+    end
   end
 end

spec/lib/shanty/cli_spec.rb

@@ -1,3 +1,4 @@
+require 'commander'
 require 'spec_helper'
 require 'shanty/cli'
 require 'shanty/env'
@@ -96,17 +97,22 @@ module Shanty
         subject.run
       end
 
-      xit('fails to run with no command specified') do
+      it('fails to run with no command specified') do
+        expect(Commander::Runner.instance).to receive(:abort).with('invalid command. Use --help for more information')
         subject.run
       end
 
-      xit('fails to run an invalid command') do
+      it('fails to run an invalid command') do
+        expect(Commander::Runner.instance).to receive(:abort).with('invalid command. Use --help for more information')
+
         ARGV.concat(%w(xulu))
 
         subject.run
       end
 
-      xit('fails to run a command when run without required options') do
+      it('fails to run a command when run without required options') do
+        expect(subject).to receive(:abort).with('missing required params: catweasel. Use --help for more information.')
+
         ARGV.concat(%w(foo))
 
         subject.run
@@ -118,7 +124,7 @@ module Shanty
         subject.run
       end
 
-      xit('executes a command correctly when run without non-required options') do
+      it('executes a command correctly when run without non-required options') do
         ARGV.concat(%w(foo --catweasel=noiamacatweasel))
 
         subject.run

spec/lib/shanty/project_template_spec.rb

@@ -12,7 +12,7 @@ module Shanty
       it('raises an exception if the given path is not a valid directory') do
         allow(File).to receive(:directory?).and_return(false)
 
-        expect { subject }.to raise_exception('Path to project must be a directory.')
+        expect { subject }.to raise_error('Path to project must be a directory.')
       end
     end