From 79384034cf6f15381ec90a60d544f02eff0b601e Mon Sep 17 00:00:00 2001
From: Florian Scholz <fs@florianscholz.com>
Date: Mon, 12 Dec 2022 18:37:41 +0100
Subject: [PATCH] Document limitations of performance.getEntries* methods
 (#22841)

* Document limitations of performance.getEntries* methods

* Move out of note
---
 .../web/api/performance/getentries/index.md   | 20 ++++++++++++-------
 .../api/performance/getentriesbyname/index.md | 10 ++++++++++
 .../api/performance/getentriesbytype/index.md | 10 ++++++++++
 3 files changed, 33 insertions(+), 7 deletions(-)

diff --git a/files/en-us/web/api/performance/getentries/index.md b/files/en-us/web/api/performance/getentries/index.md
index c75a65d6323b1ca..f551e9fec2af1d1 100644
--- a/files/en-us/web/api/performance/getentries/index.md
+++ b/files/en-us/web/api/performance/getentries/index.md
@@ -19,6 +19,16 @@ If you are only interested in performance entries of certain types or that have
 > **Note:** This method does not notify you about new performance entries; you will only get entries that are present in the performance timeline at the time you call this method.
 > To receive notifications about entries as they become available, use a {{domxref("PerformanceObserver")}}.
 
+The following entry types are not supported by this method at all and won't be returned even if entries for these types might exist:
+
+- `"element"` ({{domxref("PerformanceElementTiming")}})
+- `"event"` ({{domxref("PerformanceEventTiming")}})
+- `"largest-contentful-paint"` ({{domxref("LargestContentfulPaint")}})
+- `"layout-shift"` ({{domxref("LayoutShift")}})
+- `"longtask"` ({{domxref("PerformanceLongTaskTiming")}})
+
+To access entries of these types, you must use a {{domxref("PerformanceObserver")}} instead.
+
 ## Syntax
 
 ```js-nolint
@@ -45,21 +55,17 @@ performance.mark("login-started");
 performance.mark("login-finished");
 performance.mark("form-sent");
 performance.mark("video-loaded");
-performance.measure(
-   "login-duration",
-   "login-started",
-   "login-finished"
- );
+performance.measure("login-duration", "login-started", "login-finished");
 
 const entries = performance.getEntries();
 
 entries.forEach((entry) => {
   if (entry.entryType === "mark") {
     console.log(`${entry.name}'s startTime: ${entry.startTime}`);
-  };
+  }
   if (entry.entryType === "measure") {
     console.log(`${entry.name}'s duration: ${entry.duration}`);
-  };
+  }
 });
 ```
 
diff --git a/files/en-us/web/api/performance/getentriesbyname/index.md b/files/en-us/web/api/performance/getentriesbyname/index.md
index 99b78e5c26cf545..4134981829536d8 100644
--- a/files/en-us/web/api/performance/getentriesbyname/index.md
+++ b/files/en-us/web/api/performance/getentriesbyname/index.md
@@ -19,6 +19,16 @@ If you are interested in performance entries of certain types, see {{domxref("Pe
 > **Note:** This method does not notify you about new performance entries; you will only get entries that are present in the performance timeline at the time you call this method.
 > To receive notifications about entries as they become available, use a {{domxref("PerformanceObserver")}}.
 
+The following entry types are not supported by this method at all and won't be returned even if entries for these types might exist:
+
+- `"element"` ({{domxref("PerformanceElementTiming")}})
+- `"event"` ({{domxref("PerformanceEventTiming")}})
+- `"largest-contentful-paint"` ({{domxref("LargestContentfulPaint")}})
+- `"layout-shift"` ({{domxref("LayoutShift")}})
+- `"longtask"` ({{domxref("PerformanceLongTaskTiming")}})
+
+To access entries of these types, you must use a {{domxref("PerformanceObserver")}} instead.
+
 ## Syntax
 
 ```js-nolint
diff --git a/files/en-us/web/api/performance/getentriesbytype/index.md b/files/en-us/web/api/performance/getentriesbytype/index.md
index d6c4746fbd6ebe5..2c1e53bec1ffaf4 100644
--- a/files/en-us/web/api/performance/getentriesbytype/index.md
+++ b/files/en-us/web/api/performance/getentriesbytype/index.md
@@ -19,6 +19,16 @@ If you are interested in performance entries of certain name, see {{domxref("Per
 > **Note:** This method does not notify you about new performance entries; you will only get entries that are present in the performance timeline at the time you call this method.
 > To receive notifications about entries as they become available, use a {{domxref("PerformanceObserver")}}.
 
+The following entry types are not supported by this method at all and won't be returned even if entries for these types might exist:
+
+- `"element"` ({{domxref("PerformanceElementTiming")}})
+- `"event"` ({{domxref("PerformanceEventTiming")}})
+- `"largest-contentful-paint"` ({{domxref("LargestContentfulPaint")}})
+- `"layout-shift"` ({{domxref("LayoutShift")}})
+- `"longtask"` ({{domxref("PerformanceLongTaskTiming")}})
+
+To access entries of these types, you must use a {{domxref("PerformanceObserver")}} instead.
+
 ## Syntax
 
 ```js-nolint