From 98d3167a987f963fd91103174e98765144678491 Mon Sep 17 00:00:00 2001
From: Herman Bilous <herman_bilous@epam.com>
Date: Fri, 20 Oct 2023 11:28:59 +0300
Subject: [PATCH] [New] add allowDataUpperCase option to no-unknown-property
 rule Fixes #3643

---
 docs/rules/no-unknown-property.md      |  3 ++-
 lib/rules/no-unknown-property.js       | 23 +++++++++++++++++++----
 tests/lib/rules/no-unknown-property.js | 16 ++++++++++++++++
 3 files changed, 37 insertions(+), 5 deletions(-)

diff --git a/docs/rules/no-unknown-property.md b/docs/rules/no-unknown-property.md
index ac47ccac9d..ae8b93a678 100644
--- a/docs/rules/no-unknown-property.md
+++ b/docs/rules/no-unknown-property.md
@@ -51,12 +51,13 @@ var AtomPanel = <atom-panel class="foo"></atom-panel>;
 
 ```js
 ...
-"react/no-unknown-property": [<enabled>, { ignore: <ignore> }]
+"react/no-unknown-property": [<enabled>, { ignore: <ignore>, allowDataUpperCase: <allowDataUpperCase> }]
 ...
 ```
 
 - `enabled`: for enabling the rule. 0=off, 1=warn, 2=error. Defaults to 0.
 - `ignore`: optional array of property and attribute names to ignore during validation.
+- `allowDataUpperCase`: optional (default: `true`), allow for data-\* attributes to contain upper-case letters. React will issue a warning when data-\* attributes contain upper-case letters. In order to catch such attributes, set `allowDataUpperCase` option to `false`.
 
 If you are using a library that passes something as a prop to JSX elements, it is recommended to add those props to the ignored properties.
 
diff --git a/lib/rules/no-unknown-property.js b/lib/rules/no-unknown-property.js
index fc57336695..7ffa831ae8 100644
--- a/lib/rules/no-unknown-property.js
+++ b/lib/rules/no-unknown-property.js
@@ -16,6 +16,7 @@ const report = require('../util/report');
 
 const DEFAULTS = {
   ignore: [],
+  allowDataUpperCase: true,
 };
 
 const DOM_ATTRIBUTE_NAMES = {
@@ -418,15 +419,19 @@ function normalizeAttributeCase(name) {
 
 /**
  * Checks if an attribute name is a valid `data-*` attribute:
- * if the name starts with "data-" and has alphanumeric words (browsers require lowercase, but React and TS lowercase them),
+ * if the name starts with "data-" and has alphanumeric words,
  * not start with any casing of "xml", and separated by hyphens (-) (which is also called "kebab case" or "dash case"),
  * then the attribute is a valid data attribute.
  *
+ * Accepts option to allow upper-case letters (react will lowercase them, but will throw a warning)
+ *
  * @param {String} name - Attribute name to be tested
+ * @param {Boolean} allowUpperCase - Allow "data-*" to contain upper-case letters
  * @returns {boolean} Result
  */
-function isValidDataAttribute(name) {
-  return /^data(-[^:]*)*$/.test(name) && !/^data-xml/i.test(name);
+function isValidDataAttribute(name, allowUpperCase) {
+  const basicAttributeRegexp = allowUpperCase ? /^data(-[^:]*)*$/ : /^data(-[a-z1-9]*)*$/;
+  return basicAttributeRegexp.test(name) && !/^data-xml/i.test(name);
 }
 
 /**
@@ -516,6 +521,10 @@ module.exports = {
             type: 'string',
           },
         },
+        allowDataUpperCase: {
+          type: 'boolean',
+          default: true,
+        },
       },
       additionalProperties: false,
     }],
@@ -526,6 +535,12 @@ module.exports = {
       return (context.options[0] && context.options[0].ignore) || DEFAULTS.ignore;
     }
 
+    function getAllowDataUpperCase() {
+      return (context.options[0] && typeof context.options[0].allowDataUpperCase !== 'undefined')
+        ? context.options[0].allowDataUpperCase
+        : DEFAULTS.allowDataUpperCase;
+    }
+
     return {
       JSXAttribute(node) {
         const ignoreNames = getIgnoreConfig();
@@ -540,7 +555,7 @@ module.exports = {
           return;
         }
 
-        if (isValidDataAttribute(name)) { return; }
+        if (isValidDataAttribute(name, getAllowDataUpperCase())) { return; }
 
         if (isValidAriaAttribute(name)) { return; }
 
diff --git a/tests/lib/rules/no-unknown-property.js b/tests/lib/rules/no-unknown-property.js
index 0fc510e3b5..d2e9923148 100644
--- a/tests/lib/rules/no-unknown-property.js
+++ b/tests/lib/rules/no-unknown-property.js
@@ -99,6 +99,10 @@ ruleTester.run('no-unknown-property', rule, {
     { code: '<div data-index-number="1234"></div>;' },
     { code: '<div data-e2e-id="5678"></div>;' },
     { code: '<div data-testID="bar" data-under_sCoRe="bar" />;' },
+    {
+      code: '<div data-testID="bar" data-under_sCoRe="bar" />;',
+      options: [{ allowDataUpperCase: true }],
+    },
     // Ignoring should work
     {
       code: '<div class="bar"></div>;',
@@ -573,6 +577,18 @@ ruleTester.run('no-unknown-property', rule, {
         },
       ],
     },
+    {
+      code: '<div data-UPPERCASE="invalid" />',
+      errors: [
+        {
+          messageId: 'unknownProp',
+          data: {
+            name: 'data-UPPERCASE',
+          },
+        },
+      ],
+      options: [{ allowDataUpperCase: false }],
+    },
     {
       code: '<div abbr="abbr" />',
       errors: [