Hide password during typing with a new prompt input

examples/prompts/get-password.py

@@ -2,5 +2,5 @@
 from prompt_toolkit import prompt
 
 if __name__ == "__main__":
-    password = prompt("Password: ", is_password=True)
+    password = prompt("Password: ", is_password=True, hide_password=True)
     print(f"You said: {password}")

src/prompt_toolkit/shortcuts/prompt.py

@@ -249,6 +249,7 @@ class PromptSession(Generic[_T]):
         When True (the default), automatically wrap long lines instead of
         scrolling horizontally.
     :param is_password: Show asterisks instead of the actual typed characters.
+    :param hide_password: Hide the password, rather than showing asterisks.
     :param editing_mode: ``EditingMode.VI`` or ``EditingMode.EMACS``.
     :param vi_mode: `bool`, if True, Identical to ``editing_mode=EditingMode.VI``.
     :param complete_while_typing: `bool` or
@@ -335,10 +336,10 @@ class PromptSession(Generic[_T]):
         "lexer",
         "completer",
         "complete_in_thread",
-        "is_password",
         "editing_mode",
         "key_bindings",
         "is_password",
+        "hide_password",
         "bottom_toolbar",
         "style",
         "style_transformation",
@@ -377,6 +378,7 @@ def __init__(
         multiline: FilterOrBool = False,
         wrap_lines: FilterOrBool = True,
         is_password: FilterOrBool = False,
+        hide_password: bool = False,
         vi_mode: bool = False,
         editing_mode: EditingMode = EditingMode.EMACS,
         complete_while_typing: FilterOrBool = True,
@@ -435,6 +437,7 @@ def __init__(
         self.completer = completer
         self.complete_in_thread = complete_in_thread
         self.is_password = is_password
+        self.hide_password = hide_password
         self.key_bindings = key_bindings
         self.bottom_toolbar = bottom_toolbar
         self.style = style
@@ -555,13 +558,17 @@ def _create_layout(self) -> Layout:
         def display_placeholder() -> bool:
             return self.placeholder is not None and self.default_buffer.text == ""
 
+        password_character = "" if self.hide_password else "*"
+
         all_input_processors = [
             HighlightIncrementalSearchProcessor(),
             HighlightSelectionProcessor(),
             ConditionalProcessor(
                 AppendAutoSuggestion(), has_focus(default_buffer) & ~is_done
             ),
-            ConditionalProcessor(PasswordProcessor(), dyncond("is_password")),
+            ConditionalProcessor(
+                PasswordProcessor(char=password_character), dyncond("is_password")
+            ),
             DisplayMultipleCursors(),
             # Users can insert processors here.
             DynamicProcessor(lambda: merge_processors(self.input_processors or [])),
@@ -866,6 +873,7 @@ def prompt(
         completer: Completer | None = None,
         complete_in_thread: bool | None = None,
         is_password: bool | None = None,
+        hide_password: bool | None = None,
         key_bindings: KeyBindingsBase | None = None,
         bottom_toolbar: AnyFormattedText | None = None,
         style: BaseStyle | None = None,
@@ -961,6 +969,8 @@ class itself. For these, passing in ``None`` will keep the current
             self.complete_in_thread = complete_in_thread
         if is_password is not None:
             self.is_password = is_password
+        if hide_password is not None:
+            self.hide_password = hide_password
         if key_bindings is not None:
             self.key_bindings = key_bindings
         if bottom_toolbar is not None:
@@ -1103,6 +1113,7 @@ async def prompt_async(
         completer: Completer | None = None,
         complete_in_thread: bool | None = None,
         is_password: bool | None = None,
+        hide_password: bool | None = None,
         key_bindings: KeyBindingsBase | None = None,
         bottom_toolbar: AnyFormattedText | None = None,
         style: BaseStyle | None = None,
@@ -1155,6 +1166,8 @@ async def prompt_async(
             self.complete_in_thread = complete_in_thread
         if is_password is not None:
             self.is_password = is_password
+        if hide_password is not None:
+            self.hide_password = hide_password
         if key_bindings is not None:
             self.key_bindings = key_bindings
         if bottom_toolbar is not None:
@@ -1376,6 +1389,7 @@ def prompt(
     completer: Completer | None = None,
     complete_in_thread: bool | None = None,
     is_password: bool | None = None,
+    hide_password: bool | None = None,
     key_bindings: KeyBindingsBase | None = None,
     bottom_toolbar: AnyFormattedText | None = None,
     style: BaseStyle | None = None,
@@ -1420,7 +1434,11 @@ def prompt(
     """
     # The history is the only attribute that has to be passed to the
     # `PromptSession`, it can't be passed into the `prompt()` method.
-    session: PromptSession[str] = PromptSession(history=history)
+    # The `hide_password` is needed by the layout, so must be provided
+    # in the init as well.
+    session: PromptSession[str] = PromptSession(
+        history=history, hide_password=hide_password or False
+    )
 
     return session.prompt(
         message,

tests/test_cli.py

@@ -5,6 +5,7 @@
 
 from __future__ import annotations
 
+import io
 from functools import partial
 
 import pytest
@@ -18,6 +19,7 @@
 from prompt_toolkit.key_binding.bindings.named_commands import prefix_meta
 from prompt_toolkit.key_binding.key_bindings import KeyBindings
 from prompt_toolkit.output import DummyOutput
+from prompt_toolkit.output.plain_text import PlainTextOutput
 from prompt_toolkit.shortcuts import PromptSession
 
 
@@ -29,6 +31,33 @@ def _history():
     return h
 
 
+def _feed_cli_with_password(text, check_line_ending=True, hide_password=False):
+    """
+    Create a Prompt, feed it with a given user input considered
+    to be a password, and then return the CLI output to the caller.
+
+    This returns an Output object.
+    """
+
+    # If the given text doesn't end with a newline, the interface won't finish.
+    if check_line_ending:
+        assert text.endswith("\r")
+
+    output = PlainTextOutput(stdout=io.StringIO())
+
+    with create_pipe_input() as inp:
+        inp.send_text(text)
+        session = PromptSession(
+            input=inp,
+            output=output,
+            is_password=True,
+            hide_password=hide_password,
+        )
+
+        _ = session.prompt()
+        return output
+
+
 def _feed_cli_with_input(
     text,
     editing_mode=EditingMode.EMACS,
@@ -42,7 +71,7 @@ def _feed_cli_with_input(
     Create a Prompt, feed it with the given user input and return the CLI
     object.
 
-    This returns a (result, Application) tuple.
+    This returns a (Document, Application, Output) tuple.
     """
     # If the given text doesn't end with a newline, the interface won't finish.
     if check_line_ending:
@@ -64,6 +93,33 @@ def _feed_cli_with_input(
         return session.default_buffer.document, session.app
 
 
+def test_visible_password():
+    # Both the `result` and the `cli.current_buffer` displays the password in plain-text,
+    # but that's not what the user sees on screen.
+    password = "secret-value\r"
+    output = _feed_cli_with_password(password, hide_password=False)
+    output.stdout.seek(0)  # Reset the stream pointer
+    actual_output = output.stdout.read().strip()
+
+    # Test that the string is made up only of `*` characters
+    assert actual_output == "*" * len(actual_output), actual_output
+
+    # Test that the string is long as much as the original password,
+    # minus the needed carriage return.
+    assert actual_output == "*" * len(password.strip()), actual_output
+
+
+def test_invisible_password():
+    password = "secret-value\r"
+    output = _feed_cli_with_password(password, hide_password=True)
+    output.stdout.seek(0)  # Reset the stream pointer
+    actual_output = output.stdout.read().strip()
+
+    # Test that, if the `hide_password` flag is set to True,
+    # then then prompt won't display anything in the output.
+    assert actual_output == "", actual_output
+
+
 def test_simple_text_input():
     # Simple text input, followed by enter.
     result, cli = _feed_cli_with_input("hello\r")