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Direktori : /var/www/html/node_modules/eslint/lib/rules/ |
Current File : /var/www/html/node_modules/eslint/lib/rules/eqeqeq.js |
/** * @fileoverview Rule to flag statements that use != and == instead of !== and === * @author Nicholas C. Zakas */ "use strict"; //------------------------------------------------------------------------------ // Requirements //------------------------------------------------------------------------------ const astUtils = require("./utils/ast-utils"); //------------------------------------------------------------------------------ // Rule Definition //------------------------------------------------------------------------------ /** @type {import('../shared/types').Rule} */ module.exports = { meta: { type: "suggestion", docs: { description: "require the use of `===` and `!==`", recommended: false, url: "https://eslint.org/docs/rules/eqeqeq" }, schema: { anyOf: [ { type: "array", items: [ { enum: ["always"] }, { type: "object", properties: { null: { enum: ["always", "never", "ignore"] } }, additionalProperties: false } ], additionalItems: false }, { type: "array", items: [ { enum: ["smart", "allow-null"] } ], additionalItems: false } ] }, fixable: "code", messages: { unexpected: "Expected '{{expectedOperator}}' and instead saw '{{actualOperator}}'." } }, create(context) { const config = context.options[0] || "always"; const options = context.options[1] || {}; const sourceCode = context.getSourceCode(); const nullOption = (config === "always") ? options.null || "always" : "ignore"; const enforceRuleForNull = (nullOption === "always"); const enforceInverseRuleForNull = (nullOption === "never"); /** * Checks if an expression is a typeof expression * @param {ASTNode} node The node to check * @returns {boolean} if the node is a typeof expression */ function isTypeOf(node) { return node.type === "UnaryExpression" && node.operator === "typeof"; } /** * Checks if either operand of a binary expression is a typeof operation * @param {ASTNode} node The node to check * @returns {boolean} if one of the operands is typeof * @private */ function isTypeOfBinary(node) { return isTypeOf(node.left) || isTypeOf(node.right); } /** * Checks if operands are literals of the same type (via typeof) * @param {ASTNode} node The node to check * @returns {boolean} if operands are of same type * @private */ function areLiteralsAndSameType(node) { return node.left.type === "Literal" && node.right.type === "Literal" && typeof node.left.value === typeof node.right.value; } /** * Checks if one of the operands is a literal null * @param {ASTNode} node The node to check * @returns {boolean} if operands are null * @private */ function isNullCheck(node) { return astUtils.isNullLiteral(node.right) || astUtils.isNullLiteral(node.left); } /** * Reports a message for this rule. * @param {ASTNode} node The binary expression node that was checked * @param {string} expectedOperator The operator that was expected (either '==', '!=', '===', or '!==') * @returns {void} * @private */ function report(node, expectedOperator) { const operatorToken = sourceCode.getFirstTokenBetween( node.left, node.right, token => token.value === node.operator ); context.report({ node, loc: operatorToken.loc, messageId: "unexpected", data: { expectedOperator, actualOperator: node.operator }, fix(fixer) { // If the comparison is a `typeof` comparison or both sides are literals with the same type, then it's safe to fix. if (isTypeOfBinary(node) || areLiteralsAndSameType(node)) { return fixer.replaceText(operatorToken, expectedOperator); } return null; } }); } return { BinaryExpression(node) { const isNull = isNullCheck(node); if (node.operator !== "==" && node.operator !== "!=") { if (enforceInverseRuleForNull && isNull) { report(node, node.operator.slice(0, -1)); } return; } if (config === "smart" && (isTypeOfBinary(node) || areLiteralsAndSameType(node) || isNull)) { return; } if (!enforceRuleForNull && isNull) { return; } report(node, `${node.operator}=`); } }; } };