copy paste

test/app.test.tsx

@@ -33,6 +33,18 @@ function renderApp(): HTMLElement {
 function rowWithText(container: HTMLElement, selector: string, text: string): HTMLElement | undefined {
   return Array.from(container.querySelectorAll<HTMLElement>(selector)).find((el) => el.textContent?.includes(text))
 }
+// The tree opens fully collapsed, so expand each ancestor folder before reaching
+// a nested file. Each folder is clicked exactly once (a second click collapses).
+async function expandTo(c: HTMLElement, ...folders: string[]): Promise<void> {
+  for (const name of folders) {
+    const row = await waitFor(() => {
+      const r = rowWithText(c, '.tree-row', name)
+      if (!r) throw new Error(`folder ${name} not ready`)
+      return r
+    })
+    fireEvent.click(row)
+  }
+}
 
 describe('App (mock data, jsdom)', () => {
   it('renders the four-column workbench with the git change list', async () => {
@@ -62,6 +74,7 @@ describe('App (mock data, jsdom)', () => {
 
   it('makes an edited buffer dirty (breadcrumb dot)', async () => {
     const c = renderApp()
+    await expandTo(c, 'public', 'assets')
     const treeRow = await waitFor(() => {
       const r = rowWithText(c, '.tree-row', 'store.js')
       if (!r) throw new Error('tree not ready')