[Fix] destructuring-assignment: fix a false positive for local prop named context in SFC

Fixes #2911.

Author: SyMind

CHANGELOG.md

@@ -16,12 +16,14 @@ This change log adheres to standards from [Keep a CHANGELOG](http://keepachangel
 * [`no-array-index-key`]: support optional chaining ([#2897][] @SyMind)
 * [`no-typos`]: avoid a crash on bindingless `prop-types` import; add warning ([#2899][] @ljharb)
 * [`jsx-curly-brace-presence`]: ignore containers with comments ([#2900][] @golopot)
+* [`destructuring-assignment`]: fix a false positive for local prop named `context` in SFC ([#2929][] @SyMind)
 
 ### Changed
 * [Docs] [`jsx-no-constructed-context-values`][]: fix invalid example syntax ([#2910][] @kud)
 * [readme] Replace lists of rules with tables in readme ([#2908][] @motato1)
 * [Docs] added missing curly braces ([#2923][] @Muditxofficial)
 
+[#2929]: https://github.com/yannickcr/eslint-plugin-react/pull/2929
 [#2923]: https://github.com/yannickcr/eslint-plugin-react/pull/2923
 [#2910]: https://github.com/yannickcr/eslint-plugin-react/pull/2910
 [#2908]: https://github.com/yannickcr/eslint-plugin-react/pull/2908

lib/rules/destructuring-assignment.js

@@ -10,6 +10,40 @@ const isAssignmentLHS = require('../util/ast').isAssignmentLHS;
 
 const DEFAULT_OPTION = 'always';
 
+function createSFCParams() {
+  const queue = [];
+
+  return {
+    push(params) {
+      queue.unshift(params);
+    },
+    pop() {
+      queue.shift();
+    },
+    propsName() {
+      const found = queue.find((params) => {
+        const props = params[0];
+        return props && !props.destructuring && props.name;
+      });
+      return found && found[0] && found[0].name;
+    },
+    contextName() {
+      const found = queue.find((params) => {
+        const context = params[1];
+        return context && !context.destructuring && context.name;
+      });
+      return found && found[1] && found.name;
+    }
+  };
+}
+
+function evalParams(params) {
+  return params.map((param) => ({
+    destructuring: param.type === 'ObjectPattern',
+    name: param.type === 'Identifier' && param.name
+  }));
+}
+
 module.exports = {
   meta: {
     docs: {
@@ -46,31 +80,50 @@ module.exports = {
   create: Components.detect((context, components, utils) => {
     const configuration = context.options[0] || DEFAULT_OPTION;
     const ignoreClassFields = (context.options[1] && (context.options[1].ignoreClassFields === true)) || false;
+    const sfcParams = createSFCParams();
 
     /**
      * @param {ASTNode} node We expect either an ArrowFunctionExpression,
      *   FunctionDeclaration, or FunctionExpression
      */
     function handleStatelessComponent(node) {
-      const destructuringProps = node.params && node.params[0] && node.params[0].type === 'ObjectPattern';
-      const destructuringContext = node.params && node.params[1] && node.params[1].type === 'ObjectPattern';
+      const params = evalParams(node.params);
+
+      const SFCComponent = components.get(context.getScope(node).block);
+      if (!SFCComponent) {
+        return;
+      }
+      sfcParams.push(params);
 
-      if (destructuringProps && components.get(node) && configuration === 'never') {
+      if (params[0] && params[0].destructuring && components.get(node) && configuration === 'never') {
         context.report({
           node,
           messageId: 'noDestructPropsInSFCArg'
         });
-      } else if (destructuringContext && components.get(node) && configuration === 'never') {
+      } else if (params[1] && params[1].destructuring && components.get(node) && configuration === 'never') {
         context.report({
           node,
           messageId: 'noDestructContextInSFCArg'
         });
       }
     }
 
+    function handleStatelessComponentExit(node) {
+      const SFCComponent = components.get(context.getScope(node).block);
+      if (SFCComponent) {
+        sfcParams.pop();
+      }
+    }
+
     function handleSFCUsage(node) {
+      const propsName = sfcParams.propsName();
+      const contextName = sfcParams.contextName();
       // props.aProp || context.aProp
-      const isPropUsed = (node.object.name === 'props' || node.object.name === 'context') && !isAssignmentLHS(node);
+      const isPropUsed = (
+        (propsName && node.object.name === propsName)
+          || (contextName && node.object.name === contextName)
+      )
+        && !isAssignmentLHS(node);
       if (isPropUsed && configuration === 'always') {
         context.report({
           node,
@@ -123,6 +176,12 @@ module.exports = {
 
       FunctionExpression: handleStatelessComponent,
 
+      'FunctionDeclaration:exit': handleStatelessComponentExit,
+
+      'ArrowFunctionExpression:exit': handleStatelessComponentExit,
+
+      'FunctionExpression:exit': handleStatelessComponentExit,
+
       MemberExpression(node) {
         const SFCComponent = components.get(context.getScope(node).block);
         const classComponent = utils.getParentComponent(node);

tests/lib/rules/destructuring-assignment.js

@@ -176,6 +176,17 @@ ruleTester.run('destructuring-assignment', rule, {
     ].join('\n'),
     options: ['always', {ignoreClassFields: true}],
     parser: parsers.BABEL_ESLINT
+  },
+  // https://github.com/yannickcr/eslint-plugin-react/issues/2911
+  {
+    code: `
+      function Foo({context}) {
+        const d = context.describe()
+        return <div>{d}</div>
+      }
+    `,
+    options: ['always'],
+    parser: parsers.BABEL_ESLINT
   }],
 
   invalid: [{