From bd3454305d0afc1af2f0fb2b1cc73e6524e74c24 Mon Sep 17 00:00:00 2001
From: Peter Ju <peterju35@gmail.com>
Date: Fri, 12 Feb 2021 00:04:40 -0500
Subject: [PATCH] Retry on network errors in Firefox and Safari

---
 index.d.ts |  4 ++--
 index.js   | 12 ++++++++++--
 readme.md  |  3 ++-
 3 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/index.d.ts b/index.d.ts
index 138a76e..5b1c8a9 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -52,8 +52,8 @@ declare const pRetry: {
 	/**
 	Returns a `Promise` that is fulfilled when calling `input` returns a fulfilled promise. If calling `input` returns a rejected promise, `input` is called again until the max retries are reached, it then rejects with the last rejection reason.
 
-	It doesn't retry on `TypeError` as that's a user error. The only exclusion to this logic is when `TypeError` is thrown by `fetch`'s API with the message 'Failed to fetch', [which indicates that a request was not successful due to a network error](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch#Checking_that_the_fetch_was_successful). 
-	However, beware that `fetch` may throw `TypeError` with different error messages on different platforms for similar situations. See [whatwg/fetch#526 (comment)](https://github.com/whatwg/fetch/issues/526#issuecomment-554604080)."  
+	Does not retry on most `TypeErrors`, with the exception of network errors. This is done on a best case basis as different browsers have different [messages](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch#Checking_that_the_fetch_was_successful) to indicate this. 
+	See [whatwg/fetch#526 (comment)](https://github.com/whatwg/fetch/issues/526#issuecomment-554604080)
 
 	@param input - Receives the number of attempts as the first argument and is expected to return a `Promise` or any value.
 	@param options - Options are passed to the [`retry`](https://github.com/tim-kos/node-retry#retryoperationoptions) module.
diff --git a/index.js b/index.js
index db5fb9c..0e044ac 100644
--- a/index.js
+++ b/index.js
@@ -1,6 +1,12 @@
 'use strict';
 const retry = require('retry');
 
+const networkErrorMsgs = [
+	'Failed to fetch', // Chrome
+	'NetworkError when attempting to fetch resource', // Firefox
+	'The Internet connection appears to be offline' // Safari
+]
+
 class AbortError extends Error {
 	constructor(message) {
 		super();
@@ -16,7 +22,7 @@ class AbortError extends Error {
 		this.name = 'AbortError';
 		this.message = message;
 	}
-}
+};
 
 const decorateErrorWithCounts = (error, attemptNumber, options) => {
 	// Minus 1 from attemptNumber because the first attempt does not count as a retry
@@ -27,6 +33,8 @@ const decorateErrorWithCounts = (error, attemptNumber, options) => {
 	return error;
 };
 
+const isNetworkError = (errorMessage) => networkErrorMsgs.includes(errorMessage);
+
 const pRetry = (input, options) => new Promise((resolve, reject) => {
 	options = {
 		onFailedAttempt: () => {},
@@ -48,7 +56,7 @@ const pRetry = (input, options) => new Promise((resolve, reject) => {
 			if (error instanceof AbortError) {
 				operation.stop();
 				reject(error.originalError);
-			} else if (error instanceof TypeError && error.message !== 'Failed to fetch') {
+			} else if (error instanceof TypeError && !isNetworkError(error.message)) {
 				operation.stop();
 				reject(error);
 			} else {
diff --git a/readme.md b/readme.md
index 9a02542..8a7e91c 100644
--- a/readme.md
+++ b/readme.md
@@ -39,7 +39,8 @@ const run = async () => {
 Returns a `Promise` that is fulfilled when calling `input` returns a fulfilled promise. If calling `input` returns a rejected promise, `input` is called again until the maximum number of retries is reached. It then rejects with the last rejection reason.
 
 
-It doesn't retry on `TypeError` as that's a user error. The only exclusion to this logic is when `TypeError` is thrown by `fetch`'s API with the message 'Failed to fetch', [which indicates that a request was not successful due to a network error](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch#Checking_that_the_fetch_was_successful). However, beware that `fetch` may throw `TypeError` with different error messages on different platforms for similar situations. See [whatwg/fetch#526 (comment)](https://github.com/whatwg/fetch/issues/526#issuecomment-554604080)."  
+Does not retry on most `TypeErrors`, with the exception of network errors. This is done on a best case basis as different browsers have different [messages](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch#Checking_that_the_fetch_was_successful) to indicate this. See [whatwg/fetch#526 (comment)](https://github.com/whatwg/fetch/issues/526#issuecomment-554604080)
+
 
 #### input