Preserve preformatted text in help output.

Look for leading whitepsace such as in cases like this..
    >>> print("Hello")
    >>> print("World")

And also simple lists as long as they begin with whitespace...

 1. First
 2. Second, and last.

Note that long lines are still wrapped but will inherit the indentation
of the preformatted section.

shellish/command/command.py

@@ -20,13 +20,13 @@ def parse_docstring(entity):
     doc = inspect.getdoc(entity)
     if not doc:
         return None, None
-    doc = [x.strip() for x in doc.splitlines()]
-    if not doc[0]:
+    doc = doc.splitlines(keepends=True)
+    if not doc[0].strip():
         doc.pop(0)
-    title = (doc and doc.pop(0)) or None
-    if doc and not doc[0]:
+    title = (doc and doc.pop(0).strip()) or None
+    if doc and not doc[0].strip():
         doc.pop(0)
-    desc = '\n'.join(doc) or None
+    desc = ''.join(doc).rstrip() or None
     return title, desc
 
 
@@ -72,14 +72,13 @@ def __init__(self, parent=None, title=None, desc=None, name=None, run=None,
             self.name = name
         if self.name is None:
             raise RuntimeError("Command missing `name` attribute")
-        if type(self) is not Command:
-            alt_title, alt_desc = parse_docstring(self)
-        else:
-            alt_title, alt_desc = None, None
-        if not self.title or title:
-            self.title = title or alt_title
-        if not self.desc or desc:
-            self.desc = desc or alt_desc
+        if title is not None:
+            self.title = title
+        if desc is not None:
+            self.desc = desc
+        if self.title is None and self.desc is None and \
+           type(self) is not Command:
+            self.title, self.desc = parse_docstring(self)
         if run is not None:
             self.run = run
         if prerun is not None:

shellish/command/supplement.py

@@ -24,7 +24,8 @@ def __len__(self):
 
 class ShellishHelpFormatter(argparse.HelpFormatter):
 
-    hardline = re.compile('\n\s*\n+')
+    leadingws = re.compile('^\s+')
+    whitespace = re.compile('[ \n\t\v\f\r]+')
     max_width = 100
 
     class _Section(argparse.HelpFormatter._Section):
@@ -58,23 +59,44 @@ def format_help(self):
         return self._root_section.format_help()
 
     def _fill_text(self, text, width=None, indent=None):
-        r""" Reflow text but preserve hardlines (\n\n). """
+        """ Reflow text width while maintaining certain formatting
+        characteristics like double newlines and indented statements. """
         assert isinstance(text, str)
-        paragraphs = self.hardline.split(text)
         if indent is None:
             indent = NBSP * self._current_indent
         assert isinstance(indent, str)
+        paragraphs = []
+        line_buf = []
+        pre = ''
+        for fragment in text.splitlines():
+            pre_indent = self.leadingws.match(fragment)
+            if not fragment or pre_indent:
+                if line_buf:
+                    line = ' '.join(line_buf)
+                    paragraphs.append((pre, self.whitespace.sub(' ', line)))
+                if not fragment:
+                    paragraphs.append(('', ''))
+                else:
+                    pre = pre_indent.group()
+                    fragment = self.leadingws.sub('', fragment)
+                    paragraphs.append((pre, fragment))
+                line_buf = []
+                pre = ''
+            else:
+                line_buf.append(fragment)
+        if line_buf:
+            line = ' '.join(line_buf)
+            paragraphs.append((pre, self.whitespace.sub(' ', line)))
+        indent = VTMLBuffer(indent)
+        nl = VTMLBuffer('\n')
         if width is None:
             width = self._width - len(indent)
-        results = []
-        nl = VTMLBuffer('\n')
-        blankline = nl * 2
-        indent = VTMLBuffer(indent)
-        for x_text in paragraphs:
-            x_text = self._whitespace_matcher.sub(' ', x_text).strip()
-            results.append(nl.join((indent + x)
-                           for x in vtmlrender(x_text).wrap(width)))
-        return blankline.join(results)
+        lines = []
+        for pre, paragraph in paragraphs:
+            pwidth = width - len(pre)
+            lines.append(nl.join((indent + pre + x)
+                         for x in vtmlrender(paragraph).wrap(pwidth)))
+        return nl.join(lines)
 
     def _format_text(self, text):
         if '%(prog)' in text:
@@ -302,13 +324,15 @@ def format_help(self):
             if len(desc) == 2 and '\n' not in desc[0]:
                 title, about = desc
             else:
-                title, about = None, desc
+                title, about = '', desc
         else:
-            title, about = self.description, None
+            title, about = self.description, ''
+        title = title.strip()
+        about = about.rstrip()
         if title:
-            formatter.add_text('<b><u>%s</u></b>\n' % title.strip())
+            formatter.add_text('<b><u>%s</u></b>\n' % title)
         if about:
-            formatter.add_text(about.strip())
+            formatter.add_text(about)
         for group in self._action_groups:
             formatter.start_section(group.title)
             formatter.add_text(group.description)

shellish/rendering/vtml.py

@@ -51,8 +51,8 @@ def beststr(*strings):
 #  * Hypens are kept on leftmost word.
 #  * Newlines are not grouped with other whitespace.
 #  * Other whitespace is grouped.
-_textwrap_word_break = re.compile('(\n|[ \t\f\v]+|[^\s]+?-+)')
-_whitespace = re.compile('[ \t\f\v]+')
+_textwrap_word_break = re.compile('(\n|[ \t\f\v\r]+|[^\s]+?-+)')
+_whitespace = re.compile('[ \t\f\v\r]+')
 
 
 def is_whitespace(value):

test/basic.py

@@ -19,13 +19,13 @@ def test_no_title_desc_by_subclass(self):
         class Foo(shellish.Command):
             pass
         f = Foo(name='foo')
-        self.assertEqual(f.title, None)
-        self.assertEqual(f.desc, None)
+        self.assertIsNone(f.title)
+        self.assertIsNone(f.desc)
 
     def test_no_title_desc_by_compose(self):
         f = shellish.Command(name='foo')
-        self.assertEqual(f.title, None)
-        self.assertEqual(f.desc, None)
+        self.assertIsNone(f.title)
+        self.assertIsNone(f.desc)
 
     def test_title_desc_by_subclass_attrs(self):
         class Foo(shellish.Command):