Allow newlines inside unclosed quotes. Fixes #495

Author: kotfu

cmd2/cmd2.py

@@ -1858,8 +1858,30 @@ def _complete_statement(self, line: str) -> Statement:
         pipe runs out. We can't refactor it because we need to retain
         backwards compatibility with the standard library version of cmd.
         """
-        statement = self.statement_parser.parse(self.preparse(line))
-        while statement.multiline_command and not statement.terminator:
+        # preparse() is deprecated, use self.register_postparsing_hook() instead
+        line = self.preparse(line)
+
+        while True:
+            try:
+                statement = self.statement_parser.parse(line)
+                if statement.multiline_command and statement.terminator:
+                    # we have a completed multiline command, we are done
+                    break
+                if not statement.multiline_command:
+                    # it's not a multiline command, but we parsed it ok
+                    # so we are done
+                    break
+            except ValueError:
+                # we have unclosed quotation marks, lets parse only the command
+                # and see if it's a multiline
+                statement = self.statement_parser.parse_command_only(line)
+                if not statement.multiline_command:
+                    # not a multiline command, so raise the exception
+                    raise
+
+            # if we get here we must have:
+            #   - a multiline command with no terminator
+            #   - a multiline command with unclosed quotation marks
             if not self.quit_on_sigint:
                 try:
                     newline = self.pseudo_raw_input(self.continuation_prompt)
@@ -1885,7 +1907,6 @@ def _complete_statement(self, line: str) -> Statement:
                     newline = '\n'
                     self.poutput(newline)
                 line = '{}\n{}'.format(statement.raw, newline)
-            statement = self.statement_parser.parse(line)
 
         if not statement.command:
             raise EmptyStatement()

tests/test_cmd2.py

@@ -1471,7 +1471,8 @@ def test_multiline_complete_empty_statement_raises_exception(multiline_app):
         multiline_app._complete_statement('')
 
 def test_multiline_complete_statement_without_terminator(multiline_app):
-    # Mock out the input call so we don't actually wait for a user's response on stdin when it looks for more input
+    # Mock out the input call so we don't actually wait for a user's response
+    # on stdin when it looks for more input
     m = mock.MagicMock(name='input', return_value='\n')
     builtins.input = m
 
@@ -1481,6 +1482,20 @@ def test_multiline_complete_statement_without_terminator(multiline_app):
     statement = multiline_app._complete_statement(line)
     assert statement == args
     assert statement.command == command
+    assert statement.multiline_command == command
+
+def test_multiline_complete_statement_with_unclosed_quotes(multiline_app):
+    # Mock out the input call so we don't actually wait for a user's response
+    # on stdin when it looks for more input
+    m = mock.MagicMock(name='input', side_effect=['quotes', '" now closed;'])
+    builtins.input = m
+
+    line = 'orate hi "partially open'
+    statement = multiline_app._complete_statement(line)
+    assert statement == 'hi "partially open\nquotes\n" now closed'
+    assert statement.command == 'orate'
+    assert statement.multiline_command == 'orate'
+    assert statement.terminator == ';'
 
 
 def test_clipboard_failure(base_app, capsys):