Identified and marked a few blocks of code that can't be reached during unit tests due to the lack of a real terminal. Some more comments.

Author: anselor

cmd2/argparse_completer.py

@@ -52,6 +52,9 @@ def my_completer(text: str, line: str, begidx: int, endidx:int, extra_param: str
     The subcommand group dictionary maps subcommand names to tuple(arg_choices, subcmd_args_lookup)
 
     For more details of this more complex approach see tab_autocompletion.py in the examples
+
+Copyright 2018 Eric Lin <[email protected]>
+Released under MIT license, see LICENSE file
 """
 
 import argparse
@@ -262,6 +265,12 @@ def complete_command(self, tokens: List[str], text: str, line: str, begidx: int,
         current_is_positional = False
         consumed_arg_values = {}  # dict(arg_name -> [values, ...])
 
+        # the following are nested functions that have full access to all variables in the parent
+        # function including variables declared and updated after this function.  Variable values
+        # are current at the point the nested functions are invoked (as in, they do not receive a
+        # snapshot of these values, they directly access the current state of variables in the
+        # parent function)
+
         def consume_flag_argument() -> None:
             """Consuming token as a flag argument"""
             # we're consuming flag arguments

cmd2/cmd2.py

@@ -1591,7 +1591,7 @@ def _redirect_complete(self, text, line, begidx, endidx, compfunc):
         return compfunc(text, line, begidx, endidx)
 
     @staticmethod
-    def _pad_matches_to_display(matches_to_display):
+    def _pad_matches_to_display(matches_to_display):  # pragma: no cover
         """
         Adds padding to the matches being displayed as tab completion suggestions.
         The default padding of readline/pyreadine is small and not visually appealing
@@ -1613,7 +1613,7 @@ def _pad_matches_to_display(matches_to_display):
 
         return [cur_match + padding for cur_match in matches_to_display], len(padding)
 
-    def _display_matches_gnu_readline(self, substitution, matches, longest_match_length):
+    def _display_matches_gnu_readline(self, substitution, matches, longest_match_length):  # pragma: no cover
         """
         Prints a match list using GNU readline's rl_display_match_list()
         This exists to print self.display_matches if it has data. Otherwise matches prints.
@@ -1664,7 +1664,7 @@ def _display_matches_gnu_readline(self, substitution, matches, longest_match_len
             # Redraw prompt and input line
             rl_force_redisplay()
 
-    def _display_matches_pyreadline(self, matches):
+    def _display_matches_pyreadline(self, matches):  # pragma: no cover
         """
         Prints a match list using pyreadline's _display_completions()
         This exists to print self.display_matches if it has data. Otherwise matches prints.
@@ -3344,7 +3344,7 @@ def do_load(self, arglist):
             # self._script_dir list when done.
             with open(expanded_path, encoding='utf-8') as target:
                 self.cmdqueue = target.read().splitlines() + ['eos'] + self.cmdqueue
-        except IOError as e:
+        except IOError as e:  # pragma: no cover
             self.perror('Problem accessing script from {}:\n{}'.format(expanded_path, e))
             return
 
@@ -3371,7 +3371,7 @@ def is_text_file(file_path):
                 # noinspection PyUnusedLocal
                 if sum(1 for line in f) > 0:
                     valid_text_file = True
-        except IOError:
+        except IOError:  # pragma: no cover
             pass
         except UnicodeDecodeError:
             # The file is not ASCII. Check if it is UTF-8.
@@ -3381,7 +3381,7 @@ def is_text_file(file_path):
                     # noinspection PyUnusedLocal
                     if sum(1 for line in f) > 0:
                         valid_text_file = True
-            except IOError:
+            except IOError:  # pragma: no cover
                 pass
             except UnicodeDecodeError:
                 # Not UTF-8

cmd2/rl_utils.py

@@ -18,7 +18,7 @@
     try:
         # noinspection PyUnresolvedReferences
         import readline
-    except ImportError:
+    except ImportError:  # pragma: no cover
         pass
 
 
@@ -51,7 +51,8 @@ def rl_force_redisplay() -> None:
     """
     if not sys.stdout.isatty():
         return
-    if rl_type == RlType.GNU:
+
+    if rl_type == RlType.GNU:  # pragma: no cover
         # rl_forced_update_display() is the proper way to redraw the prompt and line, but we
         # have to use ctypes to do it since Python's readline API does not wrap the function
         readline_lib.rl_forced_update_display()
@@ -60,6 +61,6 @@ def rl_force_redisplay() -> None:
         display_fixed = ctypes.c_int.in_dll(readline_lib, "rl_display_fixed")
         display_fixed.value = 1
 
-    elif rl_type == RlType.PYREADLINE:
+    elif rl_type == RlType.PYREADLINE:  # pragma: no cover
         # noinspection PyProtectedMember
         readline.rl.mode._print_prompt()

examples/tab_autocompletion.py

@@ -1,6 +1,10 @@
 #!/usr/bin/env python
 # coding=utf-8
-"""A simple example demonstrating how to use flag and index based tab-completion functions
+"""
+A example usage of the AutoCompleter
+
+Copyright 2018 Eric Lin <[email protected]>
+Released under MIT license, see LICENSE file
 """
 import argparse
 import itertools