Suggest brew update && … when handling errors or missing methods

lib/cask/cli.rb

@@ -29,8 +29,6 @@ class Cask::CLI; end
 
 class Cask::CLI
 
-  ISSUES_URL = "https://github.com/caskroom/homebrew-cask/issues"
-
   ALIASES = {
              'ls'             => 'list',
              'homepage'       => 'home',
@@ -125,8 +123,7 @@ def self.process(arguments)
     exit 1
   rescue StandardError, ScriptError, NoMemoryError => e
     onoe e
-    puts "#{Tty.white}Please report this bug:"
-    puts "    #{Tty.em}#{ISSUES_URL}#{Tty.reset}"
+    puts Cask::Utils.error_message_with_suggestions
     puts e.backtrace
     exit 1
   end

lib/cask/utils.rb

@@ -1,10 +1,14 @@
+# encoding: UTF-8
 
 # see Homebrew Library/Homebrew/utils.rb
 
 require 'yaml'
 require 'open3'
 require 'stringio'
 
+UPDATE_CMD = "brew update && brew upgrade brew-cask && brew cleanup && brew cask cleanup"
+ISSUES_URL = "https://github.com/caskroom/homebrew-cask/issues"
+
 # monkeypatch Object - not a great idea
 class Object
   def utf8_inspect
@@ -161,20 +165,27 @@ def self.file_is_descendant(file, dir)
     return false
   end
 
-  def self.method_missing_message(method, token, section=nil)
-    during = section ? "during #{section} " : '';
-    poo = <<-EOPOO.undent
-      Unexpected method '#{method}' called #{during}on Cask #{token}.
+  def self.error_message_with_suggestions
+    <<-EOS.undent
+    #{ Tty.reset }
+      #{ Tty.white }Most likely, this means you have #{
+      }an outdated version of homebrew-cask. Please run:
+
+          #{ Tty.reset }#{ Tty.green }#{ UPDATE_CMD }#{ Tty.reset }
+
+      #{ Tty.white }If this doesn’t fix the problem, please report this bug:
 
-        If you are working on #{token}, this may point to a typo. Otherwise
-        it probably means this Cask is using a new feature. If that feature
-        has been released, running
+          #{ Tty.em }#{ Tty.white }#{ ISSUES_URL }#{ Tty.reset }
 
-          brew update && brew upgrade brew-cask && brew cleanup && brew cask cleanup
+    EOS
+  end
+
+  def self.method_missing_message(method, token, section=nil)
+    poo = []
+    poo << "Unexpected method '#{method}' called"
+    poo << "during #{section}" if section
+    poo << "on Cask #{token}."
 
-        should fix it. Otherwise you should wait to use #{token} until the
-        new feature is released.
-    EOPOO
-    poo.split("\n").each { |line| opoo line }
+    opoo(poo.join(' ') + "\n" + error_message_with_suggestions)
   end
 end

test/cask/dsl_test.rb

@@ -8,27 +8,39 @@
     test_cask.version.must_equal '1.2.3'
   end
 
-  it "prevents the entire world from crashing when a Cask includes an unknown method" do
+  describe "when a Cask includes an unknown method" do
     UnexpectedMethodCask = Class.new(Cask)
-    begin
-      TestHelper.must_output(self, lambda {
+    attempt_unknown_method = nil
+
+    before do
+      attempt_unknown_method = lambda {
         UnexpectedMethodCask.class_eval do
           future_feature :not_yet_on_your_machine
         end
-      }, <<-WARNING.undent.chomp)
-        Warning: Unexpected method 'future_feature' called on Cask unexpected-method-cask.
-        Warning:#{' '}
-        Warning:   If you are working on unexpected-method-cask, this may point to a typo. Otherwise
-        Warning:   it probably means this Cask is using a new feature. If that feature
-        Warning:   has been released, running
-        Warning:#{' '}
-        Warning:     brew update && brew upgrade brew-cask && brew cleanup && brew cask cleanup
-        Warning:#{' '}
-        Warning:   should fix it. Otherwise you should wait to use unexpected-method-cask until the
-        Warning:   new feature is released.
-      WARNING
-    rescue Exception => e
-      flunk("Wanted unexpected method to simply warn, but got exception #{e}")
+      }
+    end
+
+    it "prints a warning that it has encountered an unexpected method" do
+      expected = r = Regexp.compile(<<-EOREGEX.undent.lines.map(&:chomp).join(''))
+        (?m)
+        Warning:
+        .*
+        Unexpected method 'future_feature' called on Cask unexpected-method-cask\\.
+        .*
+        brew update && brew upgrade brew-cask && brew cleanup && brew cask cleanup
+        .*
+        https://github.com/caskroom/homebrew-cask/issues
+      EOREGEX
+
+      TestHelper.must_output(self, attempt_unknown_method, expected)
+    end
+
+    it "will simply warn, not throw an exception" do
+      begin
+        capture_subprocess_io { attempt_unknown_method.call }
+      rescue Exception => e
+        flunk("Wanted unexpected method to simply warn, but got exception #{e}")
+      end
     end
   end