retry: wrap node-retry and make it `await`-friendly

lib/retry.js

@@ -0,0 +1,29 @@
+import retrier from 'retry';
+
+export default function retry (fn, opts) {
+  return new Promise((resolve, reject) => {
+    const op = retrier.operation(opts);
+    const { onRetry } = opts;
+
+    // we allow the user to abort retrying
+    // this makes sense in the cases where
+    // knowledge is obtained that retrying
+    // would be futile (e.g.: auth errors)
+    const bail = (err) => reject(err);
+
+    op.attempt((num) => {
+      if (num > 1 && onRetry) {
+        const errs = op.errors();
+        onRetry(errs[errs.length - 1]);
+      }
+
+      fn(bail)
+      .then((val) => resolve(val))
+      .catch(err => {
+        if (!op.retry(err)) {
+          reject(op.mainError());
+        }
+      });
+    });
+  });
+}