51 lines
1.2 KiB
JavaScript
51 lines
1.2 KiB
JavaScript
/**
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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 = 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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