diff --git a/src/helpers.ts b/src/helpers.ts
index 796ba4c..9526e04 100644
--- a/src/helpers.ts
+++ b/src/helpers.ts
@@ -29,7 +29,7 @@ export function sanitizeGithubWorkflowName(name: string) {
   const nameTruncated = nameWithoutSpecialCharacters.slice(0, MAX_TAG_VALUE_LENGTH);
   return nameTruncated;
 }
-
+/* c8 ignore start */
 export function errorMessage(error: unknown) {
   return error instanceof Error ? error.message : String(error);
 }
@@ -37,8 +37,9 @@ export function errorMessage(error: unknown) {
 export function isDefined<T>(i: T | undefined | null): i is T {
   return i !== undefined && i !== null;
 }
+/* c8 ignore stop */
 
-function defaultSleep(ms: number) {
+export function defaultSleep(ms: number) {
   return new Promise((resolve) => setTimeout(resolve, ms));
 }
 let sleep = defaultSleep;
diff --git a/test/helpers.test.ts b/test/helpers.test.ts
new file mode 100644
index 0000000..452d0a6
--- /dev/null
+++ b/test/helpers.test.ts
@@ -0,0 +1,26 @@
+import * as helpers from '../src/helpers';
+describe('helpers', () => {
+  beforeEach(() => {
+    jest.resetModules();
+    jest.clearAllMocks();
+  });
+
+  test('removes brackets from GitHub Actor', () => {
+    expect(helpers.sanitizeGithubActor('foo[bot]')).toEqual('foo_bot_');
+  });
+
+  test('removes special characters from worflow names', () => {
+    expect(helpers.sanitizeGithubWorkflowName('sdf234@#$%$^&*()_+{}|:"<>?')).toEqual('sdf234@__________+___:_<>?');
+  });
+
+  test('can sleep', async () => {
+    const sleep = helpers.defaultSleep(10);
+    await expect(Promise.race([sleep, new Promise((_res, rej) => setTimeout(rej, 20))])).resolves;
+  });
+
+  test("backoff function doesn't retry non-retryable errors", async () => {
+    const fn = jest.fn().mockRejectedValue('i am not retryable');
+    await expect(helpers.retryAndBackoff(fn, false)).rejects.toMatch('i am not retryable');
+    expect(fn).toHaveBeenCalledTimes(1);
+  });
+});