Merge pull request #646 from Insti/Be_more_helpful_when_generator_can_not_be_found

Be more helpful when generator can not be found

Author: kotp

lib/generator/command_line/generator_optparser.rb

@@ -83,7 +83,9 @@ def validate_exercise
 
     def validate_cases
       return true if available_generators.include?(options[:slug])
-      $stderr.puts "A generator does not currently exist for #{options[:slug]}!"
+      warning = "A generator does not currently exist for #{options[:slug]}!"
+      expected_location = "Expecting it to be at: #{Files::GeneratorCases.source_filepath(@paths.track, options[:slug])}"
+      $stderr.puts [warning, expected_location].join("\n")
       false
     end
   end

test/generator/command_line/generator_optparser_test.rb

@@ -111,9 +111,18 @@ def test_validate_slug
     end
 
     def test_validate_missing_generator
-      args = %w(nonexistent)
+      args = %w(non-existent)
       Files::GeneratorCases.stub :available, [] do
-        assert_output(nil, /A generator does not currently exist fo/) do
+        assert_output(nil, /A generator does not currently exist for non-existent/) do
+          refute GeneratorOptparser.new(args, FixturePaths).options_valid?
+        end
+      end
+    end
+
+    def test_missing_generator_tells_you_where_it_looked
+      args = %w(non-existent)
+      Files::GeneratorCases.stub :available, [] do
+        assert_output(nil, %r{exercises/non-existent/\.meta/generator/non_existent_case\.rb}) do
           refute GeneratorOptparser.new(args, FixturePaths).options_valid?
         end
       end