fix: flaky fs test

Reported by #4390, this test is failing on the mkdirSpy call count assertion.

Not exactly sure why this is flaky, but maybe it is due
to the previous folders not being cleaned up.

This commit deletes the created folders after each test finishes.
Additionally, this commit checks the actual spy call count so that
we can better debug the issue

Signed-off-by: nkomonen <[email protected]>

packages/toolkit/src/test/srcShared/fs.test.ts

@@ -13,6 +13,7 @@ import * as os from 'os'
 import { isMinimumVersion } from '../../shared/vscode/env'
 import Sinon from 'sinon'
 import * as extensionUtilities from '../../shared/extensionUtilities'
+import crypto from 'crypto'
 
 function isWin() {
     return os.platform() === 'win32'
@@ -174,7 +175,7 @@ describe('FileSystem', function () {
                 await fsCommon.mkdir(dirPath)
 
                 assert.ok(existsSync(dirPath))
-                assert.ok(mkdirSpy.calledOnce)
+                assert.strictEqual(mkdirSpy.callCount, 1)
             })
         })
     })
@@ -299,15 +300,19 @@ describe('FileSystem', function () {
         return path.join(testRootPath(), relativePath)
     }
 
+    let _testRootPath: string | undefined
+
     function testRootPath() {
-        return path.join(fakeContext.globalStorageUri.fsPath, 'testDir')
+        _testRootPath ??= path.join(fakeContext.globalStorageUri.fsPath, crypto.randomBytes(4).toString('hex'))
+        return _testRootPath
     }
 
     async function makeTestRoot() {
         return mkdirSync(testRootPath())
     }
 
     async function deleteTestRoot() {
-        return rmSync(testRootPath(), { recursive: true })
+        rmSync(testRootPath(), { recursive: true })
+        _testRootPath = undefined
     }
 })