fix(host,client): review round 23 — create-path contract at every client declaration; close-edge resets; NFD tripwire; canonical double join

packages/client/test-runtime/src/workspaces.ts

@@ -143,14 +143,14 @@ export class TestWorkspaces implements IWorkspaces {
    * @param path - absolute existing parent directory.
    * @param name - single path segment.
    * @returns the created directory's absolute path, in the shape
-   * `DirectoryPickerBrowseCapability.createDirectory` contracts (verbatim
-   * equal to the child's `entries[].path` in the parent's next listing).
+   * `IWorkspaces.createDirectory` contracts.
    */
   async createDirectory(path: string, name: string): Promise<string> {
     this.calls.push({ method: 'createDirectory', args: [path, name] })
     const stub = this.stubs.get('createDirectory')
     if (stub !== undefined) return await (stub(path, name) as Promise<string>)
-    return `${path}/${name}`
+    // Canonical join: a bare-root parent must not double the separator.
+    return path.endsWith('/') ? `${path}${name}` : `${path}/${name}`
   }
 
   /**

packages/client/test-runtime/tests/runtime.spec.tsx

@@ -329,12 +329,16 @@ describe('workspaces', () => {
     await expect(runtime.workspaces.listDirectory()).resolves.toMatchObject({ path: '/home/test', entries: [] })
     await expect(runtime.workspaces.listDirectory('/home/test')).resolves.toMatchObject({ path: '/home/test' })
     await expect(runtime.workspaces.createDirectory('/home/test', 'fresh')).resolves.toBe('/home/test/fresh')
+    // Canonical join: a bare-root parent yields /top, not //top (the
+    // IWorkspaces contract's verbatim entries[].path equality).
+    await expect(runtime.workspaces.createDirectory('/', 'top')).resolves.toBe('/top')
     // The recorded signal seat mirrors the production face (undefined here;
     // cancellation tests pass and observe a real one).
     expect(runtime.workspaces.calls).toEqual([
       { method: 'listDirectory', args: [undefined, undefined] },
       { method: 'listDirectory', args: ['/home/test', undefined] },
       { method: 'createDirectory', args: ['/home/test', 'fresh'] },
+      { method: 'createDirectory', args: ['/', 'top'] },
     ])
     // Stubs replace the defaults like every sibling method.
     const listing = { path: '/x', home: '/x', crumbs: [], entries: [] }