Refactor parseline() for #380

Author: kotfu

cmd2/cmd2.py

@@ -1921,66 +1921,16 @@ def postparsing_postcmd(self, stop: bool) -> bool:
     def parseline(self, line):
         """Parse the line into a command name and a string containing the arguments.
 
-        NOTE: This is an override of a parent class method.  It is only used by other parent class methods.  But
-        we do need to override it here so that the additional shortcuts present in cmd2 get properly expanded for
-        purposes of tab completion.
+        NOTE: This is an override of a parent class method.  It is only used by other parent class methods.
 
-        Used for command tab completion.  Returns a tuple containing (command, args, line).
-        'command' and 'args' may be None if the line couldn't be parsed.
+        Different from the parent class method, this ignores self.identchars.
 
         :param line: str - line read by readline
         :return: (str, str, str) - tuple containing (command, args, line)
         """
-        line = line.strip()
 
-        if not line:
-            # Deal with empty line or all whitespace line
-            return None, None, line
-
-        # Make a copy of aliases so we can edit it
-        tmp_aliases = list(self.aliases.keys())
-        keep_expanding = len(tmp_aliases) > 0
-
-        # Expand aliases
-        while keep_expanding:
-            for cur_alias in tmp_aliases:
-                keep_expanding = False
-
-                if line == cur_alias or line.startswith(cur_alias + ' '):
-                    line = line.replace(cur_alias, self.aliases[cur_alias], 1)
-
-                    # Do not expand the same alias more than once
-                    tmp_aliases.remove(cur_alias)
-                    keep_expanding = len(tmp_aliases) > 0
-                    break
-
-        # Expand command shortcut to its full command name
-        for (shortcut, expansion) in self.shortcuts:
-            if line.startswith(shortcut):
-                # If the next character after the shortcut isn't a space, then insert one
-                shortcut_len = len(shortcut)
-                if len(line) == shortcut_len or line[shortcut_len] != ' ':
-                    expansion += ' '
-
-                # Expand the shortcut
-                line = line.replace(shortcut, expansion, 1)
-                break
-
-        i, n = 0, len(line)
-
-        # If we are allowing shell commands, then allow any character in the command
-        if self.default_to_shell:
-            while i < n and line[i] != ' ':
-                i += 1
-
-        # Otherwise only allow those in identchars
-        else:
-            while i < n and line[i] in self.identchars:
-                i += 1
-
-        command, arg = line[:i], line[i:].strip()
-
-        return command, arg, line
+        statement = self.statement_parser.parse_command_only(line)
+        return statement.command, statement.args, statement.command_and_args
 
     def onecmd_plus_hooks(self, line):
         """Top-level function called by cmdloop() to handle parsing a line and running the command and all of its hooks.

tests/test_cmd2.py

@@ -1718,3 +1718,21 @@ def test_ppaged(base_app):
     base_app.ppaged(msg)
     out = base_app.stdout.buffer
     assert out == msg + end
+
+# we override cmd.parseline() so we always get consistent
+# command parsing by parent methods we don't override
+# don't need to test all the parsing logic here, because
+# parseline just calls StatementParser.parse_command_only()
+def test_parseline_empty(base_app):
+    statement = ''
+    command, args, line = base_app.parseline(statement)
+    assert not command
+    assert not args
+    assert not line
+
+def test_parseline(base_app):
+    statement = " command with 'partially completed quotes  "
+    command, args, line = base_app.parseline(statement)
+    assert command == 'command'
+    assert args == "with 'partially completed quotes"
+    assert line == statement.strip()