Add retries to all API calls

__tests__/cacheHttpsClient.test.ts

@@ -0,0 +1,144 @@
+import { retry } from "../src/cacheHttpClient";
+import * as testUtils from "../src/utils/testUtils";
+
+afterEach(() => {
+    testUtils.clearInputs();
+});
+
+interface TestResponse {
+    statusCode: number;
+    result: string | null;
+}
+
+function handleResponse(
+    response: TestResponse | undefined
+): Promise<TestResponse> {
+    if (!response) {
+        fail("Retry method called too many times");
+    }
+
+    if (response.statusCode === 999) {
+        throw Error("Test Error");
+    } else {
+        return Promise.resolve(response);
+    }
+}
+
+async function testRetryExpectingResult(
+    responses: Array<TestResponse>,
+    expectedResult: string | null
+): Promise<void> {
+    responses = responses.reverse(); // Reverse responses since we pop from end
+
+    const actualResult = await retry(
+        "test",
+        () => handleResponse(responses.pop()),
+        (response: TestResponse) => response.statusCode
+    );
+
+    expect(actualResult.result).toEqual(expectedResult);
+}
+
+async function testRetryExpectingError(
+    responses: Array<TestResponse>
+): Promise<void> {
+    responses = responses.reverse(); // Reverse responses since we pop from end
+
+    expect(
+        retry(
+            "test",
+            () => 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
+    );
+});