From 678985ff3ba7acae588d9392f504699fac14e234 Mon Sep 17 00:00:00 2001
From: Jukka Kurkela <jukka.kurkela@gmail.com>
Date: Fri, 12 Feb 2021 10:42:52 +0200
Subject: [PATCH 1/3] perf: resolveObjectKey

---
 src/helpers/helpers.core.js | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/src/helpers/helpers.core.js b/src/helpers/helpers.core.js
index 20c0f6e3bdf..007eb95b71b 100644
--- a/src/helpers/helpers.core.js
+++ b/src/helpers/helpers.core.js
@@ -283,22 +283,24 @@ export function _deprecated(scope, value, previous, current) {
   }
 }
 
+function indexOfDotOrLength(key, start) {
+  const idx = key.indexOf('.', start);
+  return idx === -1 ? key.length : idx;
+}
+
 export function resolveObjectKey(obj, key) {
-  // Special cases for `x` and `y` keys. It's quite a lot faster to aceess this way.
-  // Those are the default keys Chart.js is resolving, so it makes sense to be fast.
-  if (key === 'x') {
-    return obj.x;
-  }
-  if (key === 'y') {
-    return obj.y;
+  if (!key) {
+    return obj;
   }
-  const keys = key.split('.');
-  for (let i = 0, n = keys.length; i < n && obj; ++i) {
-    const k = keys[i];
-    if (!k) {
+  let pos = 0;
+  let idx = indexOfDotOrLength(key, pos);
+  while (idx > pos) {
+    obj = obj[key.substr(pos, idx - pos)];
+    if (!obj) {
       break;
     }
-    obj = obj[k];
+    pos = idx + 1;
+    idx = indexOfDotOrLength(key, pos);
   }
   return obj;
 }

From 067791e72de8e6b38aa2b52e9408f65a2912c322 Mon Sep 17 00:00:00 2001
From: Jukka Kurkela <jukka.kurkela@gmail.com>
Date: Mon, 15 Feb 2021 22:34:27 +0200
Subject: [PATCH 2/3] Fix tests

---
 src/helpers/helpers.core.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/helpers/helpers.core.js b/src/helpers/helpers.core.js
index 007eb95b71b..5f36dd57289 100644
--- a/src/helpers/helpers.core.js
+++ b/src/helpers/helpers.core.js
@@ -289,7 +289,7 @@ function indexOfDotOrLength(key, start) {
 }
 
 export function resolveObjectKey(obj, key) {
-  if (!key) {
+  if (key === '') {
     return obj;
   }
   let pos = 0;

From 1f38eb103ca3dd7dab5e1c9d9cb14844f3f153e9 Mon Sep 17 00:00:00 2001
From: Jukka Kurkela <jukka.kurkela@gmail.com>
Date: Mon, 15 Feb 2021 22:43:00 +0200
Subject: [PATCH 3/3] prevent string construction

---
 src/helpers/helpers.core.js | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/helpers/helpers.core.js b/src/helpers/helpers.core.js
index 5f36dd57289..159c1335c4c 100644
--- a/src/helpers/helpers.core.js
+++ b/src/helpers/helpers.core.js
@@ -283,13 +283,15 @@ export function _deprecated(scope, value, previous, current) {
   }
 }
 
+const emptyString = '';
+const dot = '.';
 function indexOfDotOrLength(key, start) {
-  const idx = key.indexOf('.', start);
+  const idx = key.indexOf(dot, start);
   return idx === -1 ? key.length : idx;
 }
 
 export function resolveObjectKey(obj, key) {
-  if (key === '') {
+  if (key === emptyString) {
     return obj;
   }
   let pos = 0;