- Catch DocoptLanguageError and reraise Runfile::SyntaxError

lib/runfile/action.rb

@@ -26,7 +26,7 @@ def run(args = {})
 
       instance_eval do
         host.helpers.each { |b| b.call args }
-        block.call args
+        block.call args if block
       end
     end
 

lib/runfile/exceptions.rb

@@ -10,4 +10,5 @@ class ExitWithUsage < Error; end
   class ActionNotFound < UserError; end
   class GemNotFound < UserError; end
   class SyntaxError < UserError; end
+  class DocoptError < SyntaxError; end
 end

lib/runfile/runner.rb

@@ -14,6 +14,8 @@ def call_docopt(docopt, version: nil, argv: nil)
         Docopt.docopt docopt, argv: argv, version: version
       rescue Docopt::Exit => e
         raise ExitWithUsage, e.message
+      rescue Docopt::DocoptLanguageError => e
+        raise DocoptError, "There is an error in your runfile:\nnb`#{e.message}`"
       end
     end
   end

spec/approvals/runner/docopt-error

@@ -0,0 +1,2 @@
+#<Runfile::DocoptError: There is an error in your runfile:
+nb`unmatched '['`>

spec/runfile/runner_spec.rb

@@ -0,0 +1,16 @@
+describe Runner do
+  subject { described_class }
+
+  let(:docopt) do
+    <<~DOCOPT
+      Usage:
+        backup [PATH --force#{'  '}
+    DOCOPT
+  end
+
+  describe '#run' do
+    it 'raises Runfile::SyntaxError on docopt error' do
+      expect { subject.run docopt }.to raise_approval('runner/docopt-error')
+    end
+  end
+end