Use Azure storage SDK to download cache (#497)

* Adds option to download using AzCopy

* Bump version number and add release notes

* Ensure we use at least v10

* Negate env var so it disables AzCopy

* Use Azure storage SDK to download cache

* Use same level of parallelism as AzCopy

* Fix naming of variable

* React to feedback

* Bump Node types to Node 12

* Make linter happy

* Pass options into restoreCache method

* Fix tests

* Restructure files and add tests

* Add method to get the default download and upload options

* Include breaking changes in RELEASES.md

Co-authored-by: Josh Gross <joshmgross@github.com>

packages/cache/__tests__/requestUtils.test.ts

@@ -0,0 +1,140 @@
+import {retry} from '../src/internal/requestUtils'
+
+interface TestResponse {
+  statusCode: number
+  result: string | null
+}
+
+async function handleResponse(
+  response: TestResponse | undefined
+): Promise<TestResponse> {
+  if (!response) {
+    // eslint-disable-next-line no-undef
+    fail('Retry method called too many times')
+  }
+
+  if (response.statusCode === 999) {
+    throw Error('Test Error')
+  } else {
+    return Promise.resolve(response)
+  }
+}
+
+async function testRetryExpectingResult(
+  responses: TestResponse[],
+  expectedResult: string | null
+): Promise<void> {
+  responses = responses.reverse() // Reverse responses since we pop from end
+
+  const actualResult = await retry(
+    'test',
+    async () => handleResponse(responses.pop()),
+    (response: TestResponse) => response.statusCode
+  )
+
+  expect(actualResult.result).toEqual(expectedResult)
+}
+
+async function testRetryExpectingError(
+  responses: TestResponse[]
+): Promise<void> {
+  responses = responses.reverse() // Reverse responses since we pop from end
+
+  expect(
+    retry(
+      'test',
+      async () => handleResponse(responses.pop()),
+      (response: TestResponse) => response.statusCode
+    )
+  ).rejects.toBeInstanceOf(Error)
+}
+
+test('retry works on successful response', async () => {
+  await testRetryExpectingResult(
+    [
+      {
+        statusCode: 200,
+        result: 'Ok'
+      }
+    ],
+    'Ok'
+  )
+})
+
+test('retry works after retryable status code', async () => {
+  await testRetryExpectingResult(
+    [
+      {
+        statusCode: 503,
+        result: null
+      },
+      {
+        statusCode: 200,
+        result: 'Ok'
+      }
+    ],
+    'Ok'
+  )
+})
+
+test('retry fails after exhausting retries', async () => {
+  await testRetryExpectingError([
+    {
+      statusCode: 503,
+      result: null
+    },
+    {
+      statusCode: 503,
+      result: null
+    },
+    {
+      statusCode: 200,
+      result: 'Ok'
+    }
+  ])
+})
+
+test('retry fails after non-retryable status code', async () => {
+  await testRetryExpectingError([
+    {
+      statusCode: 500,
+      result: null
+    },
+    {
+      statusCode: 200,
+      result: 'Ok'
+    }
+  ])
+})
+
+test('retry works after error', async () => {
+  await testRetryExpectingResult(
+    [
+      {
+        statusCode: 999,
+        result: null
+      },
+      {
+        statusCode: 200,
+        result: 'Ok'
+      }
+    ],
+    'Ok'
+  )
+})
+
+test('retry returns after client error', async () => {
+  await testRetryExpectingResult(
+    [
+      {
+        statusCode: 400,
+        result: null
+      },
+      {
+        statusCode: 200,
+        result: 'Ok'
+      }
+    ],
+    null
+  )
+})