Merge pull request #312 from JoshCheek/master

Make error messages more helpful

lib/thor/base.rb

@@ -462,17 +462,11 @@ def handle_no_command_error(command, has_namespace = $thor_runner) #:nodoc:
       end
       alias handle_no_task_error handle_no_command_error
 
-      def handle_argument_error(command, error, arity=nil) #:nodoc:
-        msg = "#{basename} #{command.name}"
-        if arity && arity != 0
-          required = arity < 0 ? (-1 - arity) : arity
-          msg << " requires at least #{required} argument"
-          msg << "s" if required > 1
-        else
-          msg = "call #{msg} as"
-        end
-
-        msg << ": #{self.banner(command).inspect}."
+      def handle_argument_error(command, error, args, arity) #:nodoc:
+        msg = "ERROR: #{basename} #{command.name} was called with "
+        msg << 'no arguments'               if  args.empty?
+        msg << 'arguments ' << args.inspect if !args.empty?
+        msg << "\nUsage: #{self.banner(command).inspect}."
         raise InvocationError, msg
       end
 

lib/thor/command.rb

@@ -32,7 +32,7 @@ def run(instance, args=[])
       end
     rescue ArgumentError => e
       handle_argument_error?(instance, e, caller) ?
-        instance.class.handle_argument_error(self, e, arity) : (raise e)
+        instance.class.handle_argument_error(self, e, args, arity) : (raise e)
     rescue NoMethodError => e
       handle_no_method_error?(instance, e, caller) ?
         instance.class.handle_no_command_error(name) : (raise e)

lib/thor/group.rb

@@ -205,15 +205,10 @@ def printable_commands(*)
     end
     alias printable_tasks printable_commands
 
-    def handle_argument_error(command, error, arity=nil) #:nodoc:
-      if arity > 0
-        msg = "#{basename} #{command.name} takes #{arity} argument"
-        msg << "s" if arity > 1
-        msg << ", but it should not."
-      else
-        msg = "You should not pass arguments to #{basename} #{command.name}."
-      end
-
+    def handle_argument_error(command, error, args, arity) #:nodoc:
+      msg = "#{basename} #{command.name} takes #{arity} argument"
+      msg << "s" if arity > 1
+      msg << ", but it should not."
       raise error, msg
     end
 

spec/base_spec.rb

@@ -193,7 +193,7 @@ def hello
       thorfile = File.join(File.dirname(__FILE__), "fixtures", "script.thor")
       expect(Thor::Base.subclass_files[File.expand_path(thorfile)]).to eq([
         MyScript, MyScript::AnotherScript, MyChildScript, Barn,
-        Scripts::MyScript, Scripts::MyDefaults, Scripts::ChildDefault
+        Scripts::MyScript, Scripts::MyDefaults, Scripts::ChildDefault, Scripts::Arities
       ])
     end
 

spec/fixtures/script.thor

@@ -195,5 +195,23 @@ module Scripts
   class ChildDefault < Thor
     namespace "default:child"
   end
+
+  class Arities < Thor
+    desc "zero_args", "takes zero args"
+    def zero_args
+    end
+
+    desc "one_arg ARG", "takes one arg"
+    def one_arg(arg)
+    end
+
+    desc "two_args ARG1 ARG2", "takes two args"
+    def two_args(arg1, arg2)
+    end
+
+    desc "optional_arg [ARG]", "takes an optional arg"
+    def optional_arg(arg='default')
+    end
+  end
 end
 

spec/group_spec.rb

@@ -17,7 +17,7 @@
       expect(MyCounter.start(["1", "--third", "3"])).to eq([ 1, 2, 3, nil, nil, nil ])
     end
 
-    it "invokes all the commands in the Thor group and his parents" do
+    it "invokes all the commands in the Thor group and its parents" do
       expect(BrokenCounter.start(["1", "2", "--third", "3"])).to eq([ nil, 2, 3, false, 5, nil ])
     end
 

spec/runner_spec.rb

@@ -112,7 +112,7 @@ def when_no_thorfiles_exist
     it "does not swallow Thor InvocationError" do
       ARGV.replace ["my_script:animal"]
       content = capture(:stderr) { Thor::Runner.start }
-      expect(content.strip).to eq('thor animal requires at least 1 argument: "thor my_script:animal TYPE".')
+      expect(content.strip).to eq(%Q'ERROR: thor animal was called with no arguments\nUsage: "thor my_script:animal TYPE".')
     end
   end
 

spec/thor_spec.rb

@@ -237,8 +237,17 @@ def boring(*args)
       expect(MyScript.start(["with_optional", "--all"])).to eq([nil, { "all" => true }, []])
     end
 
-    it "raises an error if a required param is not provided" do
-      expect(capture(:stderr) { MyScript.start(["animal"]) }.strip).to eq('thor animal requires at least 1 argument: "thor my_script:animal TYPE".')
+    it "raises an error if the wrong number of params are provided" do
+      arity_asserter = lambda do |args, msg|
+        stderr = capture(:stderr) { Scripts::Arities.start(args) }
+        expect(stderr.strip).to eq(msg)
+      end
+      arity_asserter.call ["zero_args",    "one"         ], %Q'ERROR: thor zero_args was called with arguments ["one"]\nUsage: "thor scripts:arities:zero_args".'
+      arity_asserter.call ["one_arg"                     ], %Q'ERROR: thor one_arg was called with no arguments\nUsage: "thor scripts:arities:one_arg ARG".'
+      arity_asserter.call ["one_arg",      "one", "two"  ], %Q'ERROR: thor one_arg was called with arguments ["one", "two"]\nUsage: "thor scripts:arities:one_arg ARG".'
+      arity_asserter.call ["one_arg",      "one", "two"  ], %Q'ERROR: thor one_arg was called with arguments ["one", "two"]\nUsage: "thor scripts:arities:one_arg ARG".'
+      arity_asserter.call ["two_args",     "one"         ], %Q'ERROR: thor two_args was called with arguments ["one"]\nUsage: "thor scripts:arities:two_args ARG1 ARG2".'
+      arity_asserter.call ["optional_arg", "one", "two"  ], %Q'ERROR: thor optional_arg was called with arguments ["one", "two"]\nUsage: "thor scripts:arities:optional_arg [ARG]".'
     end
 
     it "raises an error if the invoked command does not exist" do