From 03f3c16e4c5f537eaf70300dac47b735feb2c41e Mon Sep 17 00:00:00 2001
From: Scott Shepherd <skot@pobox.com>
Date: Fri, 10 Sep 2021 12:07:38 -0500
Subject: [PATCH 1/2] return offset 0 and local Date if there's a error
 fetching; option to throw errors instead of console.warn

---
 serverDate.js |  7 ++++---
 test.js       | 17 +++++++++++++++++
 2 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/serverDate.js b/serverDate.js
index 4dc65b6..305f232 100644
--- a/serverDate.js
+++ b/serverDate.js
@@ -22,9 +22,9 @@ const fetchSampleImplementation = async () => {
 };
 
 export const getServerDate = async (
-  { fetchSample } = { fetchSample: fetchSampleImplementation }
+  { fetchSample, throwErrors } = { fetchSample: fetchSampleImplementation, throwErrors: false }
 ) => {
-  let best = { uncertainty: Number.MAX_VALUE };
+  let best = { date: new Date(), offset: 0, uncertainty: Number.MAX_VALUE };
 
   // Fetch 10 samples to increase the chance of getting one with low
   // uncertainty.
@@ -46,7 +46,8 @@ export const getServerDate = async (
         };
       }
     } catch (exception) {
-      console.warn(exception);
+      if (throwErrors) throw exception;
+      else console.warn(exception);
     }
   }
 
diff --git a/test.js b/test.js
index 1a13d95..8f3d379 100644
--- a/test.js
+++ b/test.js
@@ -77,3 +77,20 @@ it(`synchronizes the time with the server`, async () => {
     uncertainty: 582.5,
   });
 });
+
+it(`returns offset 0 and local Date on error`, async () => {
+  const fetchSample = async () => {
+    throw new Error(`oh dang`);
+  };
+  const { date, offset, uncertainty } = await getServerDate({ fetchSample });
+  assert(offset === 0);
+  assert(uncertainty === Number.MAX_VALUE);
+  assert(Date.now() - date < 100);
+})
+
+it(`throws errors if you ask it to`, async () => {
+  const fetchSample = async () => {
+    throw new Error(`oh dang`);
+  };
+  await assert.rejects(async () => getServerDate({ fetchSample, throwErrors: true }));
+})

From 1bb4a701764144d022e46ee5e6e5e1cdab199aaf Mon Sep 17 00:00:00 2001
From: Scott Shepherd <skot@pobox.com>
Date: Fri, 10 Sep 2021 12:49:06 -0500
Subject: [PATCH 2/2] option to report errors

---
 serverDate.js | 12 +++++++-----
 test.js       |  6 ++++--
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/serverDate.js b/serverDate.js
index 305f232..0a3ebc2 100644
--- a/serverDate.js
+++ b/serverDate.js
@@ -22,13 +22,15 @@ const fetchSampleImplementation = async () => {
 };
 
 export const getServerDate = async (
-  { fetchSample, throwErrors } = { fetchSample: fetchSampleImplementation, throwErrors: false }
+  { fetchSample, withErrors } = { fetchSample: fetchSampleImplementation, withErrors: false }
 ) => {
+  const fetchCount = 10;
+  const errors = [];
   let best = { date: new Date(), offset: 0, uncertainty: Number.MAX_VALUE };
 
   // Fetch 10 samples to increase the chance of getting one with low
   // uncertainty.
-  for (let index = 0; index < 10; index++) {
+  for (let index = 0; index < fetchCount; index++) {
     try {
       const { requestDate, responseDate, serverDate } = await fetchSample();
 
@@ -46,10 +48,10 @@ export const getServerDate = async (
         };
       }
     } catch (exception) {
-      if (throwErrors) throw exception;
-      else console.warn(exception);
+      errors.push(exception);
+      console.warn(exception);
     }
   }
 
-  return best;
+  return withErrors ? { ...best, errors, fetchCount } : best;
 };
diff --git a/test.js b/test.js
index 8f3d379..3e9e44e 100644
--- a/test.js
+++ b/test.js
@@ -88,9 +88,11 @@ it(`returns offset 0 and local Date on error`, async () => {
   assert(Date.now() - date < 100);
 })
 
-it(`throws errors if you ask it to`, async () => {
+it(`reports errors if you ask it to`, async () => {
   const fetchSample = async () => {
     throw new Error(`oh dang`);
   };
-  await assert.rejects(async () => getServerDate({ fetchSample, throwErrors: true }));
+  const { errors, fetchCount } = await getServerDate({ fetchSample, withErrors: true });
+  assert(errors.length === fetchCount);
+  assert(errors[0].message === `oh dang`);
 })