1 files changed, 35 insertions, 0 deletions
diff --git a/src/exponential_retry.js b/src/exponential_retry.js
new file mode 100644
index 0000000..96ca979
--- /dev/null
+++ b/src/exponential_retry.js
@@ -0,0 +1,35 @@
+import {
+  MAX_DEFAULT_RETRY_AMOUNT,
+  WAIT_MS,
+  RETRY_EXPONENT,
+  RETRY_EXPONENTIAL_FACTOR,
+} from "./constants.js";
+
+const wait_for = (ms) => new Promise((rs) => setTimeout(rs, ms));
+
+export const with_exponential_retry = async (
+  promise_fn,
+  validation_fn = (x) => Promise.resolve(!!x),
+  max_retries = MAX_DEFAULT_RETRY_AMOUNT,
+  retries = 0
+) => {
+  try {
+    if (retries)
+      await wait_for(
+        WAIT_MS * Math.pow(RETRY_EXPONENT, RETRY_EXPONENTIAL_FACTOR * retries)
+      );
+
+    const res = await promise_fn();
+    if (await validation_fn(res)) return res;
+
+    throw new Error("Validation predicate not satisfied");
+  } catch (e) {
+    if (retries >= max_retries) throw e;
+    return with_exponential_retry(
+      promise_fn,
+      validation_fn,
+      max_retries,
+      retries + 1
+    );
+  }
+};