Force ERB in Thor::Actions to use String buffer

Author: k0kubun

lib/thor/actions/file_manipulation.rb

@@ -113,7 +113,7 @@ def template(source, *args, &block)
       context = config.delete(:context) || instance_eval("binding")
 
       create_file destination, nil, config do
-        content = ERB.new(::File.binread(source), nil, "-", "@output_buffer").result(context)
+        content = CapturableERB.new(::File.binread(source), nil, "-", "@output_buffer").result(context)
         content = block.call(content) if block
         content
       end
@@ -312,5 +312,16 @@ def with_output_buffer(buf = "") #:nodoc:
     ensure
       self.output_buffer = old_buffer
     end
+
+    # Thor::Actions#capture depends on what kind of buffer is used in ERB.
+    # Thus CapturableERB fixes ERB to use String buffer.
+    class CapturableERB < ERB
+      def set_eoutvar(compiler, eoutvar = '_erbout')
+        compiler.put_cmd = "#{eoutvar}.concat"
+        compiler.insert_cmd = "#{eoutvar}.concat"
+        compiler.pre_cmd = ["#{eoutvar} = ''"]
+        compiler.post_cmd = [eoutvar]
+      end
+    end
   end
 end