Allow the use of space instead of = to separate the flag from its arg

Allow '-l python' instead of '-l=python' in the argument file. We still
are limited to have a single argument per line so '--skip foo bar' will
not work (neither '--skip=foo bar').

Author: eldipa

byexample/cmdline.py

@@ -4,6 +4,9 @@
 
 from .log_level import str_to_level
 from .prof import profile
+'''
+>>> from byexample.cmdline import ByexampleArgumentParser
+'''
 
 
 class _CSV(argparse.Action):
@@ -181,6 +184,74 @@ def _expand_glob_patterns(gpatterns):
     return list(set(fnames))
 
 
+class ByexampleArgumentParser(argparse.ArgumentParser):
+    def convert_arg_line_to_args(self, arg_line):
+        ''' Return a list with the arguments read from a line.
+
+            If in the line there is a flag/argument with one or more
+            values the flag may be separated from its value(s) with
+            a space and this method will replace it with an '='.
+
+            This is in order to produce a single argument for each
+            line as it is expected by argparse.ArgumentParser.
+
+            >>> parser = ByexampleArgumentParser()
+            >>> parser.convert_arg_line_to_args('--skip=foo')
+            ['--skip=foo']
+
+            >>> parser.convert_arg_line_to_args('--skip foo')
+            ['--skip=foo']
+
+            >>> parser.convert_arg_line_to_args('--skip=foo bar')
+            ['--skip=foo bar']
+
+            >>> parser.convert_arg_line_to_args('--skip foo bar')
+            ['--skip=foo bar']
+
+            >>> parser.convert_arg_line_to_args('--skip=')
+            ['--skip=']
+
+            >>> parser.convert_arg_line_to_args('--skip ')
+            ['--skip ']
+
+            >>> parser.convert_arg_line_to_args('--skip')
+            ['--skip']
+
+            >>> parser.convert_arg_line_to_args('foo')
+            ['foo']
+
+            >>> parser.convert_arg_line_to_args('foo bar')
+            ['foo bar']
+        '''
+        arg_line = arg_line.lstrip()
+        if arg_line and arg_line[0] in self.prefix_chars:
+            flag, _, value = arg_line.partition(' ')
+            value = value.lstrip()
+            if not value:
+                # the flag is argumentless or it is using '='
+                # to paste the flag with its argument,
+                # return the whole line then
+                #
+                # Ex:
+                #   -foo
+                #   -bar=32
+                #   -zaz=
+                return [arg_line]
+            else:
+                if '=' in flag:
+                    # the line already has the '=' to paste the
+                    # flag with the argument, leave them as they are
+                    #
+                    # Ex:
+                    #   -bar=32 42
+                    return [arg_line]
+
+                # Paste the flag with its value (or values) with a '='
+                return [flag + '=' + value]
+
+        return [arg_line]
+
+
 @profile
 def parse_args(args=None):
     '''Parse the arguments args and return the them.
@@ -192,7 +263,7 @@ def parse_args(args=None):
     )
 
     python_version = sys.version.split(' ', 1)[0]
-    parser = argparse.ArgumentParser(
+    parser = ByexampleArgumentParser(
         fromfile_prefix_chars='@',
         add_help=False,
         formatter_class=HelpExtraFormatter,

docs/basic/options.md

@@ -64,13 +64,13 @@ Other languages and concerns may add their owns.
 If the amount of options is a little overwhelming for you, you can
 write them down to a file and let ``byexample`` load them for you.
 
-The only convention that you need to follow is to write one option
-per line and use ``=`` for the arguments.
+The only convention that you need to follow is to write **one** option
+per line.
 
 ```shell
 $ cat test/ds/options_file
--l=python
---options="+norm-ws"
+-l python
+--options "+norm-ws"
 ```
 
 Then load it with ``@`` and the file; you can use multiple files
@@ -83,7 +83,24 @@ File test/ds/python-tutorial.v2.md, 4/4 test ran in <...> seconds
 [PASS] Pass: 4 Fail: 0 Skip: 0
 ```
 
-## Glob or file pattern expansions
+> **Note:** before `10.5.2` the options in the file required to be followed by an
+> `=` like `-l=python`; spaces were not allowed.
+
+Currently if the option receives more than one argument, you will still
+have to list *all* the arguments one per line.
+
+```shell
+$ cat test/ds/pkg/bopts2
+--skip
+test/ds/pkg/foo1.py
+test/ds/pkg/foo2.py
+--
+test/ds/pkg/foo1.py
+test/ds/pkg/foo2.py
+test/ds/pkg/bar1.py
+```
+
+## File pattern expansions
 
 Consider the following:
 
@@ -119,3 +136,30 @@ $ byexample -l python @test/ds/pkg/bopts | grep pkg | sort    # byexample: +time
 File test/ds/pkg/bar1.py, 1/1 test ran in <...> seconds
 ```
 
+<!--
+
+Extra test checking that options in a file with multiple spaces are
+interpreted correctly now that we support separate the flag from its
+value with a space (before an '=' was always required)
+
+So the following lines are equivalent
+    -skip=foo bar
+    -skip foo bar
+
+$ cat test/ds/pkg/bopts2
+<...>skip
+test/ds/pkg/foo1.py
+test/ds/pkg/foo2.py
+<...>
+
+$ byexample -l python @test/ds/pkg/bopts2 | grep pkg | sort    # byexample: +timeout=8
+File test/ds/pkg/bar1.py, 1/1 test ran in <...> seconds
+
+$ cat test/ds/pkg/bopts3
+<...>skip=test/ds/pkg/foo1.py test/ds/pkg/foo2.py
+<...>
+
+$ byexample -l python @test/ds/pkg/bopts2 | grep pkg | sort    # byexample: +timeout=8
+File test/ds/pkg/bar1.py, 1/1 test ran in <...> seconds
+
+-->

test/ds/options_file

@@ -1,2 +1,2 @@
--l=python
---options="+norm-ws"
+-l python
+--options "+norm-ws"

test/ds/pkg/bopts2

@@ -0,0 +1,7 @@
+--skip
+test/ds/pkg/foo1.py
+test/ds/pkg/foo2.py
+--
+test/ds/pkg/foo1.py
+test/ds/pkg/foo2.py
+test/ds/pkg/bar1.py

test/ds/pkg/bopts3

@@ -0,0 +1,3 @@
+--skip=test/ds/pkg/foo1.py test/ds/pkg/foo2.py
+--
+test/ds/pkg/*.py