[V4] Two edges between a node and a combo #6484

Describe the bug / 问题描述

We had a use case where after collapsing a combo we ended up with two edges between a single node and a single combo

Reproduction link / 重现链接

https://codesandbox.io/p/sandbox/frosty-firefly-7pnkm9

Steps to Reproduce the Bug or Issue / 重现步骤

Just check the codesandbox :)

G6 Version / G6 版本

4.x

Operating System / 操作系统

Windows

Browser / 浏览器

Chrome

Additional context / 补充说明

Debugging the code I found out that the two edges had the following ids (pseudocode): nodeid-comboid comboid-nodeid This suggests that there's something off with the logic used to compute the key. Would it be okay to apply a sort to ensure the key's uniqueness?

I'm referring to these lines https://github.com/antvis/G6/blob/master/packages/core/src/graph/graph.ts#L2780

We could do something like

const orderedEnds = [otherEndId, comboModel.id].sort();
const vEdgeInfo = {
  source: orderedEnds[0],
  target: orderedEnds[1],
  size,
  isVEdge: true,
}
const key = orderedEnds.join('-') ;

and remove the otherEndIsSource flag.

I could open a PR if this is approved (and I'm open to suggestions otherwise)