[Fix] destructuring-assignment: Handle destructuring of useContext in SFC

Author: ed-jinyoung-park

lib/rules/destructuring-assignment.js

@@ -39,6 +39,8 @@ module.exports = {
     const configuration = context.options[0] || DEFAULT_OPTION;
     const ignoreClassFields = (context.options[1] && (context.options[1].ignoreClassFields === true)) || false;
 
+    // set to save renamed var of useContext
+    const contextSet = new Set();
     /**
      * @param {ASTNode} node We expect either an ArrowFunctionExpression,
      *   FunctionDeclaration, or FunctionExpression
@@ -61,14 +63,24 @@ module.exports = {
     }
 
     function handleSFCUsage(node) {
-      // props.aProp || context.aProp
-      const isPropUsed = (node.object.name === 'props' || node.object.name === 'context') && !isAssignmentLHS(node);
+      // props.aProp
+      const isPropUsed = node.object.name === 'props' && !isAssignmentLHS(node);
       if (isPropUsed && configuration === 'always') {
         context.report({
           node,
           message: `Must use destructuring ${node.object.name} assignment`
         });
       }
+
+      // const foo = useContext(aContext);
+      // foo.aProp
+      const isContextUsed = contextSet.has(node.object.name) && !isAssignmentLHS(node);
+      if (isContextUsed && configuration === 'always') {
+        context.report({
+          node,
+          message: `Must use destructuring ${node.object.name} assignment`
+        });
+      }
     }
 
     function isInClassProperty(node) {
@@ -125,13 +137,29 @@ module.exports = {
         const SFCComponent = components.get(context.getScope(node).block);
 
         const destructuring = (node.init && node.id && node.id.type === 'ObjectPattern');
+        const identifier = (node.init && node.id && node.id.type === 'Identifier');
         // let {foo} = props;
-        const destructuringSFC = destructuring && (node.init.name === 'props' || node.init.name === 'context');
+        const destructuringSFC = destructuring && node.init.name === 'props';
+        // let {foo} = useContext(aContext);
+        const destructuringUseContext = destructuring && node.init.callee && node.init.callee.name === 'useContext';
+        // let foo = useContext(aContext);
+        const assignUseContext = identifier && node.init.callee && node.init.callee.name === 'useContext';
         // let {foo} = this.props;
         const destructuringClass = destructuring && node.init.object && node.init.object.type === 'ThisExpression' && (
           node.init.property.name === 'props' || node.init.property.name === 'context' || node.init.property.name === 'state'
         );
 
+        if (SFCComponent && assignUseContext) {
+          contextSet.add(node.id.name);
+        }
+
+        if (SFCComponent && destructuringUseContext && configuration === 'never') {
+          context.report({
+            node,
+            message: `Must never use destructuring ${node.init.callee.name} assignment`
+          });
+        }
+
         if (SFCComponent && destructuringSFC && configuration === 'never') {
           context.report({
             node,

tests/lib/rules/destructuring-assignment.js

@@ -176,6 +176,18 @@ ruleTester.run('destructuring-assignment', rule, {
     ].join('\n'),
     options: ['always', {ignoreClassFields: true}],
     parser: parsers.BABEL_ESLINT
+  }, {
+    code: `const MyComponent = (props) => {
+      const {foo} = useContext(aContext);
+      return <div>{foo}</div>
+    };`,
+    options: ['always']
+  }, {
+    code: `const MyComponent = (props) => {
+      const foo = useContext(aContext);
+      return <div>{foo.test}</div>
+    };`,
+    options: ['never']
   }],
 
   invalid: [{
@@ -314,5 +326,23 @@ ruleTester.run('destructuring-assignment', rule, {
     errors: [
       {message: 'Must never use destructuring state assignment'}
     ]
+  }, {
+    code: `const MyComponent = (props) => {
+      const foo = useContext(aContext);
+      return <div>{foo.test}</div>
+    };`,
+    options: ['always'],
+    errors: [
+      {message: 'Must use destructuring foo assignment'}
+    ]
+  }, {
+    code: `const MyComponent = (props) => {
+      const {foo} = useContext(aContext);
+      return <div>{foo}</div>
+    };`,
+    options: ['never'],
+    errors: [
+      {message: 'Must never use destructuring useContext assignment'}
+    ]
   }]
 });