From 41c4136632b9391adb3ac53332b312089bc4dc16 Mon Sep 17 00:00:00 2001
From: Szymon Marczak <36894700+szmarczak@users.noreply.github.com>
Date: Thu, 15 Apr 2021 15:33:49 +0200
Subject: [PATCH] Add `retry.backoffLimit` option

Fixes #1599
---
 source/core/calculate-retry-delay.ts | 10 +++++++--
 source/core/options.ts               |  5 ++++-
 test/retry.ts                        | 32 ++++++++++++++++++++++++++++
 3 files changed, 44 insertions(+), 3 deletions(-)

diff --git a/source/core/calculate-retry-delay.ts b/source/core/calculate-retry-delay.ts
index a75b5ed41..b670b561a 100644
--- a/source/core/calculate-retry-delay.ts
+++ b/source/core/calculate-retry-delay.ts
@@ -2,7 +2,13 @@ import type {RetryFunction} from './options';
 
 type Returns<T extends (...args: any) => unknown, V> = (...args: Parameters<T>) => V;
 
-const calculateRetryDelay: Returns<RetryFunction, number> = ({attemptCount, retryOptions, error, retryAfter, computedValue}) => {
+const calculateRetryDelay: Returns<RetryFunction, number> = ({
+	attemptCount,
+	retryOptions,
+	error,
+	retryAfter,
+	computedValue
+}) => {
 	if (error.name === 'RetryError') {
 		return 1;
 	}
@@ -34,7 +40,7 @@ const calculateRetryDelay: Returns<RetryFunction, number> = ({attemptCount, retr
 	}
 
 	const noise = Math.random() * 100;
-	return ((2 ** (attemptCount - 1)) * 1000) + noise;
+	return Math.min(((2 ** (attemptCount - 1)) * 1000), retryOptions.backoffLimit) + noise;
 };
 
 export default calculateRetryDelay;
diff --git a/source/core/options.ts b/source/core/options.ts
index 339362fa3..f218a66c9 100644
--- a/source/core/options.ts
+++ b/source/core/options.ts
@@ -293,6 +293,7 @@ export interface RetryOptions {
 	statusCodes: number[];
 	errorCodes: string[];
 	calculateDelay: RetryFunction;
+	backoffLimit: number;
 	maxRetryAfter?: number;
 }
 
@@ -460,6 +461,7 @@ export interface PaginationOptions<ElementType, BodyType> {
 	@default 0
 	*/
 	backoff?: number;
+
 	/**
 	The maximum amount of request that should be triggered.
 	Retries on failure are not counted towards this limit.
@@ -616,7 +618,8 @@ const defaultInternals: Options['_internals'] = {
 			'EAI_AGAIN'
 		],
 		maxRetryAfter: undefined,
-		calculateDelay: ({computedValue}) => computedValue
+		calculateDelay: ({computedValue}) => computedValue,
+		backoffLimit: Number.POSITIVE_INFINITY
 	},
 	localAddress: undefined,
 	method: 'GET',
diff --git a/test/retry.ts b/test/retry.ts
index 1a06cbe3e..4b88f5820 100644
--- a/test/retry.ts
+++ b/test/retry.ts
@@ -565,3 +565,35 @@ test('reuses request options on retry', withServer, async (t, server, got) => {
 	t.is(retryCount, 1);
 	t.is(accept, 'application/json');
 });
+
+test('respects backoffLimit', withServer, async (t, server, got) => {
+	let count = 0;
+	let timestamp = Date.now();
+	const data: number[] = [];
+
+	server.get('/', (_request, response) => {
+		count++;
+
+		const now = Date.now();
+		data.push(now - timestamp);
+		timestamp = now;
+
+		if (count === 3) {
+			response.end(JSON.stringify(data));
+		} else {
+			response.statusCode = 408;
+			response.end();
+		}
+	});
+
+	const body = await got('', {
+		retry: {
+			backoffLimit: 0
+		}
+	}).json<number[]>();
+
+	t.is(body.length, 3);
+	t.true(body[0]! < 200);
+	t.true(body[1]! < 200);
+	t.true(body[2]! < 200);
+});