@atlaskit/editor-plugin-collab-edit/dist/types/pm-plugins/mergeOverlappingSteps.d.ts

Collab Edit plugin for @atlaskit/editor-core

import type { Node as PMNode } from '@atlaskit/editor-prosemirror/model';
import type { Step } from '@atlaskit/editor-prosemirror/transform-override';
/**
 * A step paired with its inverse, as stored in the collab unconfirmed queue.
 */
export type MergeableStep = {
    inverted: Step;
    step: Step;
};
/**
 * Merge two consecutive steps into the single step they are collectively equivalent to.
 *
 * `second` must be expressed in the coordinate space produced by `first` — that is, the two must be
 * consecutive steps of the same document. The returned step maps the document from before `first`
 * to after `second`, and the returned inverse maps it back, so the result is safe to use both on
 * the wire and as a rebase buffer entry.
 *
 * Returns `null` whenever the steps do not overlap, or when the merge cannot be proven exact. A
 * `null` result always means "keep the two steps as they are", never "the steps are equivalent to
 * nothing".
 *
 * @param first The earlier step and its inverse.
 * @param second The later step and its inverse.
 * @param docBefore The document `first` applies to. Optional, but without it only ProseMirror's own
 * adjacent-step merges can be resolved, because the composed slice otherwise has to be cut out of a
 * real document. Callers lose it when the queue has been rebased over a remote step.
 */
export declare function mergeOverlappingSteps(first: MergeableStep, second: MergeableStep, docBefore?: PMNode): MergeableStep | null;