Fixed not being able to clear CompletionItem.text.

Reduced number of dataclasses.replace() operations
of completion classes by adding private setters.

Author: kmvanbrunt

cmd2/cmd2.py

@@ -29,7 +29,6 @@
 import argparse
 import contextlib
 import copy
-import dataclasses
 import functools
 import glob
 import inspect
@@ -2515,31 +2514,27 @@ def _perform_completion(
         if not completions:
             return Completions()
 
-        _add_opening_quote = False
-        _quote_char = completion_token_quote
+        add_opening_quote = False
+        quote_char = completion_token_quote
 
         # Check if we need to add an opening quote
         if not completion_token_quote:
             matches = completions.to_strings()
 
             if any(" " in match for match in matches):
-                _add_opening_quote = True
+                add_opening_quote = True
 
                 # Determine best quote (single vs double) based on text content
-                _quote_char = "'" if any('"' in t for t in matches) else '"'
+                quote_char = "'" if any('"' in t for t in matches) else '"'
 
         # Check if we need to remove text from the beginning of completions
         elif text_to_remove:
-            new_items = [
-                dataclasses.replace(
-                    item,
-                    text=item.text.replace(text_to_remove, "", 1),
-                )
-                for item in completions
-            ]
-            completions = dataclasses.replace(completions, items=new_items)
+            for item in completions:
+                item._set_text(item.text.replace(text_to_remove, "", 1))
 
-        return dataclasses.replace(completions, _add_opening_quote=_add_opening_quote, _quote_char=_quote_char)
+        completions._set_add_opening_quote(add_opening_quote)
+        completions._set_quote_char(quote_char)
+        return completions
 
     def complete(
         self,
@@ -2599,21 +2594,12 @@ def complete(
             # Check if we need to restore a shortcut in the completion text
             # so it doesn't get erased from the command line.
             if completions and shortcut_to_restore:
-                new_items = [
-                    dataclasses.replace(
-                        item,
-                        text=shortcut_to_restore + item.text,
-                    )
-                    for item in completions
-                ]
+                for item in completions:
+                    item._set_text(shortcut_to_restore + item.text)
 
-                # Update items and set _quote_from_offset so that any auto-inserted
+                # Update search text offset so that any auto-inserted
                 # opening quote is placed after the shortcut.
-                completions = dataclasses.replace(
-                    completions,
-                    items=new_items,
-                    _search_text_offset=len(shortcut_to_restore),
-                )
+                completions._set_search_text_offset(len(shortcut_to_restore))
 
             # Swap between COLUMN and MULTI_COLUMN style based on the number of matches.
             if len(completions) > self.max_column_completion_results:

cmd2/completion.py

@@ -1,5 +1,6 @@
 """Provides classes and functions related to command-line completion."""
 
+import copy
 import re
 import sys
 from collections.abc import (
@@ -39,12 +40,15 @@ class CompletionItem:
     # control sequences (like ^J or ^I) in the completion menu.
     _CONTROL_WHITESPACE_RE = re.compile(r"\r\n|[\n\r\t\f\v]")
 
-    # The underlying object this completion represents (e.g., str, int, Path).
-    # This is used to support argparse choices validation.
+    # The core object this completion represents (e.g., str, int, Path).
+    # This serves as the default source for the completion string and is used
+    # to support object-based validation when used in argparse choices.
     value: Any = field(kw_only=False)
 
-    # The actual string that will be inserted into the command line.
-    # If not provided, it defaults to str(value).
+    # The actual completion string. If this is empty, it defaults to str(value)
+    # during initialization. This can be used to provide a human-friendly alias
+    # for complex objects in an argparse choices list (requires a matching
+    # 'type' converter for validation).
     text: str = ""
 
     # Optional string for displaying the completion differently in the completion menu.
@@ -59,10 +63,16 @@ class CompletionItem:
     # argument's table_columns. This is stored internally as a tuple.
     table_data: Sequence[Any] = field(default_factory=tuple)
 
+    def _set_text(self, text: str) -> None:
+        """Update the completion string.
+
+        Used internally by cmd2 to prepare the value for the command line.
+        """
+        object.__setattr__(self, "text", text)
+
     # Plain text versions of display fields (stripped of ANSI) for sorting/filtering.
-    # These are set in __post_init__().
-    display_plain: str = field(init=False)
-    display_meta_plain: str = field(init=False)
+    display_plain: str = field(default="", init=False)
+    display_meta_plain: str = field(default="", init=False)
 
     @classmethod
     def _clean_display(cls, val: str) -> str:
@@ -78,7 +88,7 @@ def _clean_display(cls, val: str) -> str:
 
     def __post_init__(self) -> None:
         """Finalize the object after initialization."""
-        # Derive text from value if it wasn't explicitly provided
+        # If the completion string is empty, derive it from value
         if not self.text:
             object.__setattr__(self, "text", str(self.value))
 
@@ -163,13 +173,15 @@ class CompletionResultsBase:
 
     # True if every item in this collection has a numeric display string.
     # Used for sorting and alignment.
-    numeric_display: bool = field(init=False)
+    numeric_display: bool = field(default=False, init=False)
 
     def __post_init__(self) -> None:
         """Finalize the object after initialization."""
         from . import utils
 
-        unique_items = utils.remove_duplicates(self.items)
+        # Remove duplicates and then copy the items so any changes made during completion
+        # don't affect the originals (e.g., persistent CompletionItems in a choices list)
+        unique_items = [copy.copy(item) for item in utils.remove_duplicates(self.items)]
 
         # Determine if all items have numeric display strings
         numeric_display = bool(unique_items) and all(self._NUMERIC_RE.match(i.display_plain) for i in unique_items)
@@ -262,18 +274,34 @@ class Completions(CompletionResultsBase):
     # This flag is ignored if there are multiple matches.
     allow_finalization: bool = True
 
-    #####################################################################
-    # The following fields are used internally by cmd2 to handle
-    # automatic quoting and are not intended for user modification.
-    #####################################################################
-
     # Whether to add an opening quote to the matches.
-    _add_opening_quote: bool = False
+    _add_opening_quote: bool = field(default=False, init=False)
 
     # The starting index of the user-provided search text within a full match.
     # This accounts for leading shortcuts (e.g., in '?cmd', the offset is 1).
     # Used to ensure opening quotes are inserted after the shortcut rather than before it.
-    _search_text_offset: int = 0
+    _search_text_offset: int = field(default=0, init=False)
 
     # The quote character to use if adding an opening or closing quote to the matches.
-    _quote_char: str = ""
+    _quote_char: str = field(default="", init=False)
+
+    def _set_add_opening_quote(self, value: bool) -> None:
+        """Set whether to add an opening quote.
+
+        Used internally by cmd2 for automatic quoting.
+        """
+        object.__setattr__(self, "_add_opening_quote", value)
+
+    def _set_search_text_offset(self, value: int) -> None:
+        """Set the search text offset.
+
+        Used internally by cmd2 for automatic quoting.
+        """
+        object.__setattr__(self, "_search_text_offset", value)
+
+    def _set_quote_char(self, value: str) -> None:
+        """Set the quote character.
+
+        Used internally by cmd2 for automatic quoting.
+        """
+        object.__setattr__(self, "_quote_char", value)

tests/test_completion.py

@@ -1300,3 +1300,14 @@ def test_subcommand_tab_completion_with_no_completer_scu(scu_app) -> None:
 
     completions = scu_app.complete(text, line, begidx, endidx)
     assert not completions
+
+
+def test_completion_item_blank_text() -> None:
+    # Verify that CompletionItem correctly handles blank text when set via _set_text
+    value = "something"
+    item = CompletionItem(value=value)
+    assert item.text == value
+
+    item._set_text("")
+    assert item.text == ""
+    assert item.display == value

tests/test_pt_utils.py

@@ -400,12 +400,11 @@ def test_get_completions_add_opening_quote_and_abort(self, line, match, search_t
 
         # Set up matches
         completion_items = [cmd2.CompletionItem(match)]
-        cmd2_completions = cmd2.Completions(
-            completion_items,
-            _add_opening_quote=True,
-            _search_text_offset=search_text_offset,
-            _quote_char='"',
-        )
+        cmd2_completions = cmd2.Completions(completion_items)
+        cmd2_completions._set_add_opening_quote(True)
+        cmd2_completions._set_search_text_offset(search_text_offset)
+        cmd2_completions._set_quote_char('"')
+
         mock_cmd_app.complete.return_value = cmd2_completions
 
         # Call get_completions
@@ -442,12 +441,11 @@ def test_get_completions_add_opening_quote_and_return_results(
         # Set up matches
         completion_items = [cmd2.CompletionItem(match) for match in matches]
 
-        cmd2_completions = cmd2.Completions(
-            completion_items,
-            _add_opening_quote=True,
-            _search_text_offset=search_text_offset,
-            _quote_char=quote_char,
-        )
+        cmd2_completions = cmd2.Completions(completion_items)
+        cmd2_completions._set_add_opening_quote(True)
+        cmd2_completions._set_search_text_offset(search_text_offset)
+        cmd2_completions._set_quote_char(quote_char)
+
         mock_cmd_app.complete.return_value = cmd2_completions
 
         # Call get_completions
@@ -483,7 +481,8 @@ def test_get_completions_allow_finalization(
 
         # Set up matches
         completion_items = [cmd2.CompletionItem(match)]
-        cmd2_completions = cmd2.Completions(completion_items, _quote_char=quote_char)
+        cmd2_completions = cmd2.Completions(completion_items)
+        cmd2_completions._set_quote_char(quote_char)
         mock_cmd_app.complete.return_value = cmd2_completions
 
         # Call get_completions and compare results
@@ -515,8 +514,8 @@ def test_get_completions_do_not_allow_finalization(
         cmd2_completions = cmd2.Completions(
             completion_items,
             allow_finalization=False,
-            _quote_char=quote_char,
         )
+        cmd2_completions._set_quote_char(quote_char)
         mock_cmd_app.complete.return_value = cmd2_completions
 
         # Call get_completions and compare results