Fix formatting triggering on swapping lines

[rchl]

With a yaml file like:

services:
  foo:
    ports:
      - 80:80
      - 81:81
    container_name: bar

Place cursor on the container_name line and move the line up (cmd+ctrl+up on Mac).
Yaml server ends up adding dash where the cursor is.

Screen.Recording.2026-04-07.at.07.15.21.mov

Fix by identifying swap command as change action so the edit is not treated as type action.

Instead of explicit command name just look for swap_line to cater for different variants of the command including from third party packages (I'm using SmarterLineMoves which overrides swap commands with smart_* variants.

[rchl]

While this is obviously our bug that we trigger OnTypeFormatting in this case, I wonder whether the position we are sending to the server is actually not correct. Should we instead figure out position based on where the edit ends? Spec says:

/**
	 * The position around which the on type formatting should happen.
	 * This is not necessarily the exact position where the character denoted
	 * by the property `ch` got typed.
	 */
	position: [Position](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#position);

which leaves quite a bit for interpretation.

[jwortmann]

Should we instead figure out position based on where the edit ends?

I think using the caret position should be appropriate. So I would maybe have used selection.b here

LSP/plugin/session_buffer.py

Line 789 in 93a0815

**text_document_position_params(view, selection.a),

although it shouldn't make any difference because the selection region should always be empty while typing.

I guess the formulation with "around" from the docstring is because the edit could change text that is not directly at the caret position (like inserting f at the front of an f-string).