add /editor command

Opens an editor for constructing a user prompt, using the currently defined chat mode.

The editor is determined as follows:

Look for the following environment variables, in order:

1. AIDER_EDITOR
2. VISUAL
3. EDITOR

If none of these are defined, use the following defaults:

Windows: notepad
OS X: vim
*nix: vi

If an editor is not found, a RuntimeError is raised.

Any arguments passed after the /editor command are inserted as content.

The temporary file used for editing has an .md extension, which can be leveraged for syntax highlighting.

NOTE: The editor used MUST block the process until the editor is closed -- the default editors all do this.

aider/commands.py

@@ -1357,6 +1357,13 @@ class Commands:
 
         report_github_issue(issue_text, title=title, confirm=False)
 
+    def cmd_editor(self, initial_content=""):
+        "Open an editor to write a prompt"
+        from aider.editor import pipe_editor
+        user_input = pipe_editor(initial_content, suffix="md")
+        self.io.display_user_input(user_input)
+        self._generic_chat_command(user_input, self.coder.edit_format)
+
 
 def expand_subdir(file_path):
     if file_path.is_file():

aider/editor.py

@@ -0,0 +1,146 @@
+"""
+Editor module for handling system text editor interactions.
+
+This module provides functionality to:
+- Discover and launch the system's configured text editor
+- Create and manage temporary files for editing
+- Handle editor preferences from environment variables
+- Support cross-platform editor operations
+"""
+
+import os
+import tempfile
+import subprocess
+import platform
+import shlex
+from rich.console import Console
+
+SYSTEM = platform.system()
+
+DEFAULT_EDITOR_NIX = "vi"
+DEFAULT_EDITOR_OS_X = "vim"
+DEFAULT_EDITOR_WINDOWS = "notepad"
+
+console = Console()
+
+
+def print_status_message(success: bool, message: str, style: str | None = None) -> None:
+    """
+    Print a status message with appropriate styling.
+
+    :param success: Whether the operation was successful
+    :param message: The message to display
+    :param style: Optional style override. If None, uses green for success and red for failure
+    """
+    if style is None:
+        style = "bold green" if success else "bold red"
+    console.print(message, style=style)
+    print("")
+
+
+def write_temp_file(input_data: str = "", suffix: str | None = None, prefix: str | None = None, dir: str | None = None) -> str:
+    """
+    Create a temporary file with the given input data.
+
+    :param input_data: Content to write to the temporary file
+    :param suffix: Optional file extension (without the dot)
+    :param prefix: Optional prefix for the temporary filename
+    :param dir: Optional directory to create the file in
+    :return: Path to the created temporary file
+    :raises: OSError if file creation or writing fails
+    """
+    kwargs = {"prefix": prefix, "dir": dir}
+    if suffix:
+        kwargs["suffix"] = f".{suffix}"
+    fd, filepath = tempfile.mkstemp(**kwargs)
+    try:
+        with os.fdopen(fd, 'w') as f:
+            f.write(input_data)
+    except Exception:
+        os.close(fd)
+        raise
+    return filepath
+
+
+def get_environment_editor(default: str | None = None) -> str | None:
+    """
+    Fetches the preferred editor from the environment variables.
+
+    This function checks the following environment variables in order to
+    determine the user's preferred editor:
+
+     - AIDER_EDITOR
+     - VISUAL
+     - EDITOR
+
+    :param default: The default editor to return if no environment variable is set.
+    :type default: str or None
+    :return: The preferred editor as specified by environment variables or the default value.
+    :rtype: str or None
+    """
+    editor = os.environ.get("AIDER_EDITOR", os.environ.get("VISUAL", os.environ.get("EDITOR", default)))
+    return editor
+
+
+def discover_editor() -> list[str]:
+    """
+    Discovers and returns the appropriate editor command as a list of arguments.
+
+    Handles cases where the editor command includes arguments, including quoted arguments
+    with spaces (e.g. 'vim -c "set noswapfile"').
+
+    :return: A list of command parts ready for subprocess execution
+    :rtype: list[str]
+    """
+    if SYSTEM == "Windows":
+        default_editor = DEFAULT_EDITOR_WINDOWS
+    elif SYSTEM == "Darwin":
+        default_editor = DEFAULT_EDITOR_OS_X
+    else:
+        default_editor = DEFAULT_EDITOR_NIX
+    editor = get_environment_editor(default_editor)
+    try:
+        return shlex.split(editor)
+    except ValueError as e:
+        raise RuntimeError(f"Invalid editor command format '{editor}': {e}")
+
+
+def file_editor(filepath: str) -> None:
+    """
+    Open the specified file in the system's configured editor.
+
+    This function blocks until the editor is closed.
+
+    :param filepath: Path to the file to edit
+    :type filepath: str
+    :raises RuntimeError: If the editor command is invalid
+    """
+    command_parts = discover_editor()
+    command_parts.append(filepath)
+    subprocess.call(command_parts)
+
+
+def pipe_editor(input_data: str = "", suffix: str | None = None) -> str:
+    """
+    Opens the system editor with optional input data and returns the edited content.
+
+    This function creates a temporary file with the provided input data, opens it in
+    the system editor, waits for the user to make changes and close the editor, then
+    reads and returns the modified content. The temporary file is deleted afterwards.
+
+    :param input_data: Initial content to populate the editor with
+    :type input_data: str
+    :param suffix: Optional file extension for the temporary file (e.g. '.txt', '.md')
+    :type suffix: str or None
+    :return: The edited content after the editor is closed
+    :rtype: str
+    """
+    filepath = write_temp_file(input_data, suffix)
+    file_editor(filepath)
+    with open(filepath, "r") as f:
+        output_data = f.read()
+    try:
+        os.remove(filepath)
+    except PermissionError:
+        print_status_message(False, f"WARNING: Unable to delete temporary file {filepath!r}. You may need to delete it manually.")
+    return output_data

aider/io.py

@@ -457,14 +457,17 @@ class InputOutput:
             log_file.write(f"{role.upper()} {timestamp}\n")
             log_file.write(content + "\n")
 
+    def display_user_input(self, inp):
+        if self.pretty and self.user_input_color:
+            style = dict(style=self.user_input_color)
+        else:
+            style = dict()
+
+        self.console.print(Text(inp), **style)
+
     def user_input(self, inp, log_only=True):
         if not log_only:
-            if self.pretty and self.user_input_color:
-                style = dict(style=self.user_input_color)
-            else:
-                style = dict()
-
-            self.console.print(Text(inp), **style)
+            self.display_user_input(inp)
 
         prefix = "####"
         if inp: