"use strict"; Object.defineProperty(exports, "__esModule", { value: true }); const utils_1 = require("../utils"); const ast_utils_1 = require("../utils/ast-utils"); const compat_1 = require("../utils/compat"); /** * Splits the given node by the given logical operator. * @param operator Logical operator `||` or `&&`. * @param node The node to split. * @returns Array of conditions that makes the node when joined by the operator. */ function splitByLogicalOperator(operator, node) { if (node.type === 'LogicalExpression' && node.operator === operator) { return [ ...splitByLogicalOperator(operator, node.left), ...splitByLogicalOperator(operator, node.right) ]; } return [node]; } /** * Split with ||. */ function splitByOr(node) { return splitByLogicalOperator('||', node); } /** * Split with &&. */ function splitByAnd(node) { return splitByLogicalOperator('&&', node); } /** * Build OrOperands */ function buildOrOperands(node) { const orOperands = splitByOr(node); return { node, operands: orOperands.map((orOperand) => { const andOperands = splitByAnd(orOperand); return { node: orOperand, operands: andOperands }; }) }; } exports.default = (0, utils_1.createRule)('no-dupe-else-if-blocks', { meta: { docs: { description: 'disallow duplicate conditions in `{#if}` / `{:else if}` chains', category: 'Possible Errors', recommended: true }, schema: [], messages: { unexpected: 'This branch can never execute. Its condition is a duplicate or covered by previous conditions in the `{#if}` / `{:else if}` chain.' }, type: 'problem' // "problem", }, create(context) { const sourceCode = (0, compat_1.getSourceCode)(context); /** * Determines whether the two given nodes are considered to be equal. In particular, given that the nodes * represent expressions in a boolean context, `||` and `&&` can be considered as commutative operators. * @param a First node. * @param b Second node. * @returns `true` if the nodes are considered to be equal. */ function equal(a, b) { if (a.type !== b.type) { return false; } if (a.type === 'LogicalExpression' && b.type === 'LogicalExpression' && (a.operator === '||' || a.operator === '&&') && a.operator === b.operator) { return ((equal(a.left, b.left) && equal(a.right, b.right)) || (equal(a.left, b.right) && equal(a.right, b.left))); } return (0, ast_utils_1.equalTokens)(a, b, sourceCode); } /** * Determines whether the first given AndOperands is a subset of the second given AndOperands. * * e.g. A: (a && b), B: (a && b && c): B is a subset of A. * * @param operandsA The AndOperands to compare from. * @param operandsB The AndOperands to compare against. * @returns `true` if the `andOperandsA` is a subset of the `andOperandsB`. */ function isSubset(operandsA, operandsB) { return operandsA.operands.every((operandA) => operandsB.operands.some((operandB) => equal(operandA, operandB))); } /** Iterate SvelteIfBlock nodes */ function* iterateIfElseIf(node) { let target = node; while (target.parent.type === 'SvelteElseBlock' && target.parent.children.includes(target) && target.parent.parent.type === 'SvelteIfBlock') { yield target.parent.parent; target = target.parent.parent; } } return { SvelteIfBlock(node) { const test = node.expression; const conditionsToCheck = test.type === 'LogicalExpression' && test.operator === '&&' ? [...splitByAnd(test), test] : [test]; const listToCheck = conditionsToCheck.map(buildOrOperands); for (const currentIdBlock of iterateIfElseIf(node)) { if (currentIdBlock.expression) { const currentOrOperands = buildOrOperands(currentIdBlock.expression); for (const condition of listToCheck) { const operands = (condition.operands = condition.operands.filter((orOperand) => { return !currentOrOperands.operands.some((currentOrOperand) => isSubset(currentOrOperand, orOperand)); })); if (!operands.length) { context.report({ node: condition.node, messageId: 'unexpected' }); return; } } } } } }; } });