Check expression statements for context displayname

Author: JulesBlm

lib/rules/display-name.js

@@ -80,30 +80,52 @@ module.exports = {
     /**
      * Checks if the node is a React.createContext call
      * @param {ASTNode} node - The AST node being checked.
-     * @returns {Boolean} - True if node is a React.createContext call object literal, false if not.
+     * @returns {Boolean} - True if node is a React.createContext call, false if not.
      */
     function isCreateContext(node) {
-      if (!node.init) {
-        return false;
-      }
-
       if (
-        node.init.type === 'CallExpression'
+        node.init
+        && node.init.type === 'CallExpression'
         && node.init.callee
         && node.init.callee.name === 'createContext'
       ) {
         return true;
       }
 
       if (
-        node.init.callee
+        node.init
+        && node.init.callee
         && node.init.callee.type === 'MemberExpression'
         && node.init.callee.property
         && node.init.callee.property.name === 'createContext'
       ) {
         return true;
       }
 
+      if (
+        node.expression
+        && node.expression.type === 'AssignmentExpression'
+        && node.expression.operator === '='
+        && node.expression.right.type === 'CallExpression'
+        && node.expression.right.callee
+        && node.expression.right.callee.name === 'createContext'
+      ) {
+        return true;
+      }
+
+      if (
+        node.expression
+        && node.expression.type === 'AssignmentExpression'
+        && node.expression.operator === '='
+        && node.expression.right.type === 'CallExpression'
+        && node.expression.right.callee
+        && node.expression.right.callee.type === 'MemberExpression'
+        && node.expression.right.callee.property
+        && node.expression.right.callee.property.name === 'createContext'
+      ) {
+        return true;
+      }
+
       return false;
     }
 
@@ -191,6 +213,11 @@ module.exports = {
     // --------------------------------------------------------------------------
 
     return {
+      ExpressionStatement(node) {
+        if (checkContextObjects && isCreateContext(node)) {
+          contextObjects.set(node.expression.left.name, { node, hasDisplayName: false });
+        }
+      },
       VariableDeclarator(node) {
         if (checkContextObjects && isCreateContext(node)) {
           contextObjects.set(node.id.name, { node, hasDisplayName: false });

tests/lib/rules/display-name.js

@@ -839,6 +839,16 @@ ruleTester.run('display-name', rule, {
       code: `
         import { createContext } from 'react';
 
+        let Hello;
+        Hello = createContext();
+        Hello.displayName = "HelloContext";
+      `,
+      options: [{ checkContextObjects: true }],
+    },
+    {
+      code: `
+        import { createContext } from 'react';
+
         const Hello = createContext();
       `,
       settings: {
@@ -852,13 +862,21 @@ ruleTester.run('display-name', rule, {
       code: `
         import { createContext } from 'react';
 
-        const Hello = createContext();
+        var Hello;
+        Hello = createContext();
+        Hello.displayName = "HelloContext";
       `,
-      settings: {
-        react: {
-          version: '>16.3.0',
-        },
-      },
+      options: [{ checkContextObjects: true }],
+    },
+    {
+      code: `
+        import { createContext } from 'react';
+
+        var Hello;
+        Hello = React.createContext();
+        Hello.displayName = "HelloContext";
+      `,
+      options: [{ checkContextObjects: true }],
     },
   ]),
 
@@ -1327,5 +1345,35 @@ ruleTester.run('display-name', rule, {
       ],
       options: [{ checkContextObjects: true }],
     },
+    {
+      code: `
+        import { createContext } from 'react';
+
+        var Hello;
+        Hello = createContext();
+      `,
+      errors: [
+        {
+          messageId: 'noContextDisplayName',
+          line: 5,
+        },
+      ],
+      options: [{ checkContextObjects: true }],
+    },
+    {
+      code: `
+        import { createContext } from 'react';
+
+        var Hello;
+        Hello = React.createContext();
+      `,
+      errors: [
+        {
+          messageId: 'noContextDisplayName',
+          line: 5,
+        },
+      ],
+      options: [{ checkContextObjects: true }],
+    },
   ]),
 });