47 lines
1.2 KiB
JavaScript
47 lines
1.2 KiB
JavaScript
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'use strict';
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const isSameReference = require('../utils/is-same-reference.js');
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const {getParenthesizedRange} = require('../utils/parentheses.js');
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const {isNumberLiteral} = require('../ast/index.js');
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const isLengthMemberExpression = node =>
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node.type === 'MemberExpression'
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&& !node.computed
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&& !node.optional
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&& node.property.type === 'Identifier'
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&& node.property.name === 'length';
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const isLiteralPositiveNumber = node =>
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isNumberLiteral(node)
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&& node.value > 0;
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function getNegativeIndexLengthNode(node, objectNode) {
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if (!node) {
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return;
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}
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const {type, operator, left, right} = node;
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if (type !== 'BinaryExpression' || operator !== '-' || !isLiteralPositiveNumber(right)) {
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return;
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}
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if (isLengthMemberExpression(left) && isSameReference(left.object, objectNode)) {
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return left;
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}
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// Nested BinaryExpression
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return getNegativeIndexLengthNode(left, objectNode);
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}
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function removeLengthNode(node, fixer, sourceCode) {
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const [start, end] = getParenthesizedRange(node, sourceCode);
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return fixer.removeRange([
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start,
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end + sourceCode.text.slice(end).match(/\S|$/).index,
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]);
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}
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module.exports = {
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getNegativeIndexLengthNode,
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removeLengthNode,
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};
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