52 lines
		
	
	
		
			1.1 KiB
		
	
	
	
		
			JavaScript
		
	
	
		
			Executable File
		
	
	
	
	
			
		
		
	
	
			52 lines
		
	
	
		
			1.1 KiB
		
	
	
	
		
			JavaScript
		
	
	
		
			Executable File
		
	
	
	
	
/**
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 * @fileoverview Rule to flag comparisons to null without a type-checking
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 * operator.
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 * @author Ian Christian Myers
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 */
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"use strict";
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//------------------------------------------------------------------------------
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// Rule Definition
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//------------------------------------------------------------------------------
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/** @type {import('../types').Rule.RuleModule} */
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module.exports = {
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	meta: {
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		type: "suggestion",
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		docs: {
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			description:
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				"Disallow `null` comparisons without type-checking operators",
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			recommended: false,
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			url: "https://eslint.org/docs/latest/rules/no-eq-null",
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		},
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		schema: [],
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		messages: {
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			unexpected: "Use '===' to compare with null.",
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		},
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	},
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	create(context) {
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		return {
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			BinaryExpression(node) {
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				const badOperator =
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					node.operator === "==" || node.operator === "!=";
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				if (
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					(node.right.type === "Literal" &&
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						node.right.raw === "null" &&
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						badOperator) ||
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					(node.left.type === "Literal" &&
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						node.left.raw === "null" &&
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						badOperator)
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				) {
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					context.report({ node, messageId: "unexpected" });
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				}
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			},
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		};
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	},
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};
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