test: add unit test for folderTree in workbench

[mortalYoung]

简介

• folderTree 新增测试用例
• 修复 folderTree 的 onContextMenu 方法参数不一致的问题
• 提取 mock scrollable 组件的方法

主要变更

• onContextMenu 参数不一致的原因是因为 folderTree 本身有一个 contextMenu ，treeNode 有一个 contextMenu，公用了 onContextMenu 这个方法，然后本身的 contextMenu 是没有第二个 treeNode 的参数的

[codecov]

Codecov Report

Merging #391 (aecb20f) into main (f8eddab) will increase coverage by 1.54%.
The diff coverage is 56.25%.

@@            Coverage Diff             @@
##             main     #391      +/-   ##
==========================================
+ Coverage   75.17%   76.72%   +1.54%     
==========================================
  Files         176      176              
  Lines        4806     4808       +2     
  Branches     1036     1039       +3     
==========================================
+ Hits         3613     3689      +76     
+ Misses       1185     1111      -74     
  Partials        8        8              

Impacted Files	Coverage Δ
src/controller/explorer/explorer.tsx	43.39% <0.00%> (ø)
src/controller/explorer/folderTree.tsx	20.28% <0.00%> (-0.30%)	⬇️
...c/services/workbench/explorer/folderTreeService.ts	96.49% <ø> (ø)
src/workbench/sidebar/explore/folderTree.tsx	97.61% <100.00%> (+86.77%)	⬆️
src/components/tree/index.tsx	89.02% <0.00%> (+1.21%)	⬆️
src/common/dom.ts	77.96% <0.00%> (+3.38%)	⬆️

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[mortalYoung]

ci 不通过的原因是因为修改了 controller 而 controller 目前还么有测试用例的覆盖，所以报错了

[wewoor]

+1