refactor: used to in retry

Changelog: refactor

src/retry.ts

@@ -11,6 +11,14 @@ type RetryOptions = {
   delay?: number;
 };
 
+/**
+ * Type representing the output of the retry function.
+ * The result is a tuple that includes either an error or a value, and the duration in milliseconds.
+ * 
+ * @template T The type of the resolved value of the promise.
+ */
+type RetryOut<T> = [Error, null] | [null, T];
+
 /**
  * Retries a promise-returning function a specified number of times with an optional delay between attempts if it fails.
  *
@@ -19,23 +27,22 @@ type RetryOptions = {
  * @param {number} attempts - The number of retry attempts. Must be a positive integer.
  * @param {RetryOptions} [options] - Optional settings for retry behavior.
  * @param {number} [options.delay=0] - The delay (in milliseconds) between retry attempts.
- * @returns {Promise<T>} The resolved value of the promise.
- * @throws {Error} Throws an error if all retry attempts fail.
+ * @returns {Promise<RetryOut<T>>} A promise that resolves to a tuple containing either an error or a value, and the duration in milliseconds.
  *
  * @includeExample examples/retry.ts
  */
 export async function retry<T>(
   fn: () => Promise<T>,
   attempts: number,
   options?: RetryOptions
-): Promise<T> {
+): Promise<RetryOut<T>> {
   // Ensure the number of attempts is greater than 0
   if (attempts < 1) {
-    throw new Error("attempts must be greater than 0");
+    return [new Error("retry: attempts must be greater than 0"), null];
   }
   // Ensure the number of attempts is an integer
   if (attempts % 1 !== 0) {
-    throw new Error("attempts must be an integer");
+    return [new Error("retry: attempts must be a positive integer"), null];
   }
 
   let lastError!: Error; // Placeholder for the last encountered error
@@ -45,7 +52,7 @@ export async function retry<T>(
 
   // Ensure the delay amount is non-negative
   if (delayAmount < 0) {
-    throw new Error("delay must be greater than or equal to 0");
+    return [new Error("retry: delay must be non-negative"), null];
   }
 
   // Loop to retry the function the specified number of times
@@ -54,7 +61,7 @@ export async function retry<T>(
     const [error, result] = await to(fn());
     // If no error, return the result
     if (!error) {
-      return result;
+      return [null, result];
     }
 
     // If there's a delay, wait for the specified amount of time before the next attempt
@@ -65,5 +72,5 @@ export async function retry<T>(
   }
 
   // If all attempts fail, throw the last encountered error
-  throw lastError;
+  return [lastError, null];
 }