[Refactor] improve performance of rule merging

Author: golopot

CHANGELOG.md

@@ -31,7 +31,9 @@ This change log adheres to standards from [Keep a CHANGELOG](https://keepachange
 * [Refactor] improve performance by avoiding unnecessary `Components.detect` ([#3273][] @golopot)
 * [Refactor] add `isParenthesized` AST util ([#3203][] @Belco90)
 * [Docs] `default-props-match-prop-types`, `require-default-props`, `sort-prop-types`: fix typos ([#3279][] @nix6839)
+* [Refactor] improve performance of rule merging ([#3281][] @golopot)
 
+[#3281]: https://github.com/jsx-eslint/eslint-plugin-react/pull/3281
 [#3280]: https://github.com/jsx-eslint/eslint-plugin-react/pull/3280
 [#3279]: https://github.com/jsx-eslint/eslint-plugin-react/pull/3279
 [#3273]: https://github.com/jsx-eslint/eslint-plugin-react/pull/3273

lib/util/Components.js

@@ -247,6 +247,39 @@ function getWrapperFunctions(context, pragma) {
   ]);
 }
 
+// eslint-disable-next-line valid-jsdoc
+/**
+ * Merge many eslint rules into one
+ * @param {{[_: string]: Function}[]} rules the returned values for eslint rule.create(context)
+ * @returns {{[_: string]: Function}} merged rule
+ */
+function mergeRules(rules) {
+  /** @type {Map<string, Function[]>} */
+  const handlersByKey = new Map();
+  rules.forEach((rule) => {
+    Object.keys(rule).forEach((key) => {
+      const fns = handlersByKey.get(key);
+      if (!fns) {
+        handlersByKey.set(key, [rule[key]]);
+      } else {
+        fns.push(rule[key]);
+      }
+    });
+  });
+
+  /** @type {{[key: string]: Function}} */
+  const rule = {};
+  handlersByKey.forEach((fns, key) => {
+    rule[key] = function mergedHandler(node) {
+      fns.forEach((fn) => {
+        fn(node);
+      });
+    };
+  });
+
+  return rule;
+}
+
 function componentRule(rule, context) {
   const pragma = pragmaUtil.getFromContext(context);
   const sourceCode = context.getSourceCode();
@@ -859,44 +892,21 @@ function componentRule(rule, context) {
     },
   };
 
-  // Update the provided rule instructions to add the component detection
   const ruleInstructions = rule(context, components, utils);
-  const updatedRuleInstructions = Object.assign({}, ruleInstructions);
   const propTypesInstructions = propTypesUtil(context, components, utils);
   const usedPropTypesInstructions = usedPropTypesUtil(context, components, utils);
   const defaultPropsInstructions = defaultPropsUtil(context, components, utils);
-  const allKeys = new Set(Object.keys(detectionInstructions).concat(
-    Object.keys(propTypesInstructions),
-    Object.keys(usedPropTypesInstructions),
-    Object.keys(defaultPropsInstructions),
-    Object.keys(reactImportInstructions)
-  ));
 
-  allKeys.forEach((instruction) => {
-    updatedRuleInstructions[instruction] = (node) => {
-      if (instruction in detectionInstructions) {
-        detectionInstructions[instruction](node);
-      }
-      if (instruction in propTypesInstructions) {
-        propTypesInstructions[instruction](node);
-      }
-      if (instruction in usedPropTypesInstructions) {
-        usedPropTypesInstructions[instruction](node);
-      }
-      if (instruction in defaultPropsInstructions) {
-        defaultPropsInstructions[instruction](node);
-      }
-      if (instruction in reactImportInstructions) {
-        reactImportInstructions[instruction](node);
-      }
-      if (ruleInstructions[instruction]) {
-        return ruleInstructions[instruction](node);
-      }
-    };
-  });
+  const mergedRule = mergeRules([
+    detectionInstructions,
+    propTypesInstructions,
+    usedPropTypesInstructions,
+    defaultPropsInstructions,
+    reactImportInstructions,
+    ruleInstructions,
+  ]);
 
-  // Return the updated rule instructions
-  return updatedRuleInstructions;
+  return mergedRule;
 }
 
 module.exports = Object.assign(Components, {