Rework usage message building and support arguments in mutexes

Ref #11.

spec/mutex_spec.lua

@@ -19,6 +19,24 @@ describe("tests related to mutexes", function()
       assert.same({}, args)
    end)
 
+   it("handles mutex with an argument", function()
+      local parser = Parser()
+      parser:mutex(
+         parser:flag "-q" "--quiet"
+            :description "Supress output.",
+         parser:argument "log"
+            :args "?"
+            :description "Log file"
+      )
+
+      local args = parser:parse{"-q"}
+      assert.same({quiet = true}, args)
+      args = parser:parse{"log.txt"}
+      assert.same({log = "log.txt"}, args)
+      args = parser:parse{}
+      assert.same({}, args)
+   end)
+
    it("handles mutex with default value", function()
       local parser = Parser()
       parser:mutex(
@@ -48,6 +66,24 @@ describe("tests related to mutexes", function()
       end, "option '--quiet' can not be used together with option '-v'")
    end)
 
+   it("raises an error if mutex with an argument is broken", function()
+      local parser = Parser()
+      parser:mutex(
+         parser:flag "-q" "--quiet"
+            :description "Supress output.",
+         parser:argument "log"
+            :args "?"
+            :description "Log file"
+      )
+
+      assert.has_error(function()
+         parser:parse{"-q", "log.txt"}
+      end, "argument 'log' can not be used together with option '-q'")
+      assert.has_error(function()
+         parser:parse{"log.txt", "--quiet"}
+      end, "option '--quiet' can not be used together with argument 'log'")
+   end)
+
    it("handles multiple mutexes", function()
       local parser = Parser()
       parser:mutex(

spec/usage_spec.lua

@@ -194,7 +194,31 @@ Usage: foo ([-q] | [-v] | [-i]) ([-l] | [-f <from>])
       )
    end)
 
-    it("puts vararg option and mutex usages after positional arguments", function()
+   it("creates correct usage message for mutexes with arguments", function()
+      local parser = Parser "foo"
+         :add_help(false)
+
+      parser:argument "first"
+      parser:mutex(
+         parser:flag "-q" "--quiet",
+         parser:flag "-v" "--verbose",
+         parser:argument "second":args "?"
+      )
+      parser:argument "third"
+      parser:mutex(
+         parser:flag "-l" "--local",
+         parser:option "-f" "--from"
+      )
+      parser:option "--yet-another-option"
+
+      assert.equal([=[
+Usage: foo ([-l] | [-f <from>])
+       [--yet-another-option <yet_another_option>] <first>
+       ([-q] | [-v] | [<second>]) <third>]=], parser:get_usage()
+      )
+   end)
+
+   it("puts vararg option and mutex usages after positional arguments", function()
       local parser = Parser "foo"
          :add_help(false)
       parser:argument("argument")
@@ -217,4 +241,34 @@ Usage: foo ([-q] | [-v] | [-i])
        [--vararg-option <vararg_option> [<vararg_option>]]]=], parser:get_usage()
       )
    end)
+
+   it("doesn't repeat usage of elements within several mutexes", function()
+      local parser = Parser "foo"
+         :add_help(false)
+
+      parser:argument("arg1")
+      local arg2 = parser:argument("arg2"):args "?"
+      parser:argument("arg3"):args "?"
+      local arg4 = parser:argument("arg4"):args "?"
+
+      local opt1 = parser:option("--opt1")
+      local opt2 = parser:option("--opt2")
+      local opt3 = parser:option("--opt3")
+      local opt4 = parser:option("--opt4")
+      local opt5 = parser:option("--opt5")
+      local opt6 = parser:option("--opt6")
+      parser:option("--opt7")
+
+      parser:mutex(arg2, opt1, opt2)
+      parser:mutex(arg4, opt2, opt3, opt4)
+      parser:mutex(opt1, opt3, opt5)
+      parser:mutex(opt1, opt3, opt6)
+
+      assert.equal([=[
+Usage: foo ([--opt1 <opt1>] | [--opt3 <opt3>] | [--opt5 <opt5>])
+       [--opt6 <opt6>] [--opt7 <opt7>] <arg1>
+       ([<arg2>] | [--opt2 <opt2>]) [<arg3>]
+       ([<arg4>] | [--opt4 <opt4>])]=], parser:get_usage()
+      )
+   end)
 end)