add spy to file hash test

Author: Hweinstock

packages/core/src/testInteg/perf/getFileSha384.test.ts

@@ -4,10 +4,18 @@
  */
 import assert from 'assert'
 import path from 'path'
+import sinon from 'sinon'
 import { getTestWorkspaceFolder } from '../integrationTestsUtilities'
 import { fs, getRandomString } from '../../shared'
 import { LspController } from '../../amazonq'
 import { performanceTest } from '../../shared/performance/performance'
+import { FileSystem } from '../../shared/fs/fs'
+import { getFsCallsUpperBound } from './utilities'
+
+interface SetupResult {
+    testFile: string
+    fsSpy: sinon.SinonSpiedInstance<FileSystem>
+}
 
 function performanceTestWrapper(label: string, fileSize: number) {
     return performanceTest(
@@ -37,14 +45,15 @@ function performanceTestWrapper(label: string, fileSize: number) {
                     const fileContent = getRandomString(fileSize)
                     const testFile = path.join(workspace, 'test-file')
                     await fs.writeFile(testFile, fileContent)
-
-                    return testFile
+                    const fsSpy = sinon.spy(fs)
+                    return { testFile, fsSpy }
                 },
-                execute: async (testFile: string) => {
-                    return await LspController.instance.getFileSha384(testFile)
+                execute: async (setup: SetupResult) => {
+                    return await LspController.instance.getFileSha384(setup.testFile)
                 },
-                verify: async (_testFile: string, result: string) => {
+                verify: async (setup: SetupResult, result: string) => {
                     assert.strictEqual(result.length, 96)
+                    assert.ok(getFsCallsUpperBound(setup.fsSpy) <= 1, 'makes a single call to fs')
                 },
             }
         }
@@ -53,6 +62,9 @@ function performanceTestWrapper(label: string, fileSize: number) {
 
 describe('getFileSha384', function () {
     describe('performance tests', function () {
+        afterEach(function () {
+            sinon.restore()
+        })
         performanceTestWrapper('1MB', 1000)
         performanceTestWrapper('2MB', 2000)
         performanceTestWrapper('4MB', 4000)