Deprecate relying on default exit_on_failure? [rails#621]

lib/thor/base.rb

@@ -647,6 +647,7 @@ def from_superclass(method, default = nil)
 
       # A flag that makes the process exit with status 1 if any error happens.
       def exit_on_failure?
+        Thor.deprecation_warning 'Thor exit with status 0 on errors. To keep this behavior, you must define `exit_on_failure?`'
         false
       end
 

spec/fixtures/command.thor

@@ -1,6 +1,10 @@
 # module: random
 
 class Amazing < Thor
+  def self.exit_on_failure?
+    false
+  end
+
   desc "describe NAME", "say that someone is amazing"
   method_options :forcefully => :boolean
   def describe(name, opts)

spec/fixtures/script.thor

@@ -1,6 +1,10 @@
 class MyScript < Thor
   check_unknown_options! :except => :with_optional
 
+  def self.exit_on_failure?
+    false
+  end
+
   attr_accessor :some_attribute
   attr_writer :another_attribute
   attr_reader :another_attribute
@@ -200,6 +204,10 @@ module Scripts
   end
 
   class Arities < Thor
+    def self.exit_on_failure?
+      false
+    end
+
     desc "zero_args", "takes zero args"
     def zero_args
     end

spec/subcommand_spec.rb

@@ -55,6 +55,10 @@ def foo(name)
       class Parent < Thor
         desc "child1", "child1 description"
         subcommand "child1", Child1
+
+        def self.exit_on_failure?
+          false
+        end
       end
     end
 

spec/thor_spec.rb

@@ -173,6 +173,10 @@ def boring(*args)
         def exec(*args)
           [options, args]
         end
+
+        def self.exit_on_failure?
+          false
+        end
       end
 
       it "passes remaining args to command when it encounters a non-option" do
@@ -223,6 +227,10 @@ def exec(*args)
       def checked(*args)
         [options, args]
       end
+
+      def self.exit_on_failure?
+        false
+      end
     end
 
     it "still accept options and arguments" do
@@ -285,6 +293,10 @@ def exec(*args)
       def boring(*args)
         [options, args]
       end
+
+      def self.exit_on_failure?
+        false
+      end
     end
 
     it "does not check the required option in the given command" do
@@ -736,4 +748,19 @@ def unknown(*args)
       expect(MyScript.start(%w(send))).to eq(true)
     end
   end
+
+  context "without an exit_on_failure? method" do
+    my_script = Class.new(Thor) do
+      desc "no arg", "do nothing"
+      def no_arg
+      end
+    end
+
+    it "outputs a deprecation warning on error" do
+      expect do
+        my_script.start(%w[no_arg one])
+      end.to output(/^Deprecation.*exit_on_failure/).to_stderr
+    end
+  end
+
 end