fix -- handling and required arg detection

docs/changelog.txt

@@ -44,7 +44,9 @@ changelog.txt uses a syntax similar to RST, with a few special sequences:
 ## Lua
 - ``gui.Painter``: fixed error when calling ``viewport()`` method
 - `xlsxreader`: Added Lua class wrappers for the xlsxreader plugin API
-- ``utils.processArgsGetopt()``: now returns negative numbers (e.g. ``-10``) in the list of positional parameters instead of treating it as an option string equivalent to ``-1 -0``.
+- ``utils.processArgsGetopt()``: now returns negative numbers (e.g. ``-10``) in the list of positional parameters instead of treating it as an option string equivalent to ``-1 -0``
+- ``utils.processArgsGetopt()``: now properly handles ``--`` as a marker to treat all further parameters as non-options
+- ``utils.processArgsGetopt()``: now detects when a required arguments to long-form options are missing
 
 ## Documentation
 - Added more client library implementations to the `remote interface docs <remote-client-libs>`

library/lua/3rdparty/alt_getopt.lua

@@ -100,6 +100,7 @@ function get_ordered_opts(args, sh_opts, long_opts)
         local a = args[optind]
         if a == '--' then
             optind = optind + 1
+            break
         elseif a:sub(1, 2) == '--' then
             local pos = a:find('=', 1, true)
             if pos then
@@ -113,7 +114,7 @@ function get_ordered_opts(args, sh_opts, long_opts)
                 local opt = a:sub(3)
                 opts[count] = opt
                 if has_arg(options, opt) then
-                    if i == #args then
+                    if optind == #args then
                         qerror(string.format(
                                 'Missing value for option "%s"', a))
                     end

test/library/utils.lua

@@ -91,9 +91,13 @@ function test.processArgsGetopt_happy_path()
     args = {'nonopt1', '-nfoo', 'nonopt2', '-1', '-10', '-0v'}
     expect.table_eq({'nonopt1', 'nonopt2', '-1', '-10', '-0v'},
                     process(args, false, false, 'foo'))
+
+    args = {'nonopt1', '--', '-nfoo', '--nonopt2', 'nonopt3'}
+    expect.table_eq({'nonopt1', '-nfoo', '--nonopt2', 'nonopt3'},
+                    process(args, false, false, nil))
 end
 
-function test.processArgsGetopt_errors()
+function test.processArgsGetopt_action_errors()
     expect.error_match('missing option letter',
         function() utils.processArgsGetopt({}, {{handler=function() end}}) end)
 
@@ -106,3 +110,37 @@ function test.processArgsGetopt_errors()
     expect.error_match('handler missing',
         function() utils.processArgsGetopt({}, {{'r'}}) end)
 end
+
+function test.processArgsGetopt_parsing_errors()
+    expect.error_match('Unknown option',
+                       function() utils.processArgsGetopt({'-abc'},
+                                    {{'a', handler=function() end}})
+                       end,
+                       'use undefined short option')
+
+    expect.error_match('Unknown option',
+                       function() utils.processArgsGetopt({'--abc'},
+                                    {{'a', handler=function() end}})
+                       end,
+                       'use undefined long option')
+
+    expect.error_match('Bad usage',
+                       function() utils.processArgsGetopt({'--ab=c'},
+                                    {{'a', 'ab', handler=function() end}})
+                       end,
+                       'pass value to param that does not take one')
+
+    expect.error_match('Missing value',
+                       function() utils.processArgsGetopt({'-a'},
+                                    {{'a', 'ab', hasArg=true,
+                                      handler=function() end}})
+                       end,
+                       'fail to pass value to short param that requires one')
+
+    expect.error_match('Missing value',
+                       function() utils.processArgsGetopt({'--ab'},
+                                    {{'a', 'ab', hasArg=true,
+                                      handler=function() end}})
+                       end,
+                       'fail to pass value to long param that requires one')
+end