Type Editor

---

Type Editor / @type-editor/dom-change-util / parse-change/should-adjust-change-start-to-selection / shouldAdjustChangeStartToSelection

Function: shouldAdjustChangeStartToSelection()

function shouldAdjustChangeStartToSelection(
  change,
  selection,
  parseFrom,
): boolean;

Defined in: parse-change/should-adjust-change-start-to-selection.ts:28

Checks if change start should be adjusted to selection start.

When typing at the start of a selection, if the typed character matches the character at the selection start, the diff algorithm might place the change start after that matching character. This function detects that case.

The adjustment is needed when:

• The detected change starts after the selection start
• But is very close (within 2 positions) to the selection start
• And the selection start is within the parsed range

The threshold of 2 positions handles multi-byte characters and ensures we don't over-adjust.

Parameters

Parameter	Type	Description
change	DocumentChange	The detected document change
selection	PmSelection	Current editor selection state
parseFrom	number	Start position of the parsed range in the document. Used to verify selection is within parsed content.

Returns

boolean

True if the change start should be adjusted to match selection.from, false if no adjustment is needed