init source

node_modules/eslint-plugin-react/lib/rules/no-redundant-should-component-update.js

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+/**
+ * @fileoverview Flag shouldComponentUpdate when extending PureComponent
+ */
+
+'use strict';
+
+const Components = require('../util/Components');
+const astUtil = require('../util/ast');
+const docsUrl = require('../util/docsUrl');
+
+function errorMessage(node) {
+  return `${node} does not need shouldComponentUpdate when extending React.PureComponent.`;
+}
+
+// ------------------------------------------------------------------------------
+// Rule Definition
+// ------------------------------------------------------------------------------
+
+module.exports = {
+  meta: {
+    docs: {
+      description: 'Flag shouldComponentUpdate when extending PureComponent',
+      category: 'Possible Errors',
+      recommended: false,
+      url: docsUrl('no-redundant-should-component-update')
+    },
+    schema: []
+  },
+
+  create: Components.detect((context, components, utils) => {
+    /**
+     * Checks for shouldComponentUpdate property
+     * @param {ASTNode} node The AST node being checked.
+     * @returns {Boolean} Whether or not the property exists.
+     */
+    function hasShouldComponentUpdate(node) {
+      const properties = astUtil.getComponentProperties(node);
+      return properties.some((property) => {
+        const name = astUtil.getPropertyName(property);
+        return name === 'shouldComponentUpdate';
+      });
+    }
+
+    /**
+     * Get name of node if available
+     * @param {ASTNode} node The AST node being checked.
+     * @return {String} The name of the node
+     */
+    function getNodeName(node) {
+      if (node.id) {
+        return node.id.name;
+      }
+      if (node.parent && node.parent.id) {
+        return node.parent.id.name;
+      }
+      return '';
+    }
+
+    /**
+     * Checks for violation of rule
+     * @param {ASTNode} node The AST node being checked.
+     */
+    function checkForViolation(node) {
+      if (utils.isPureComponent(node)) {
+        const hasScu = hasShouldComponentUpdate(node);
+        if (hasScu) {
+          const className = getNodeName(node);
+          context.report({
+            node,
+            message: errorMessage(className)
+          });
+        }
+      }
+    }
+
+    return {
+      ClassDeclaration: checkForViolation,
+      ClassExpression: checkForViolation
+    };
+  })
+};