diff options
Diffstat (limited to 'tools/node_modules/eslint/lib/rules/no-mixed-operators.js')
| -rw-r--r-- | tools/node_modules/eslint/lib/rules/no-mixed-operators.js | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/tools/node_modules/eslint/lib/rules/no-mixed-operators.js b/tools/node_modules/eslint/lib/rules/no-mixed-operators.js new file mode 100644 index 0000000000..9f1fbc9a6d --- /dev/null +++ b/tools/node_modules/eslint/lib/rules/no-mixed-operators.js @@ -0,0 +1,209 @@ +/** + * @fileoverview Rule to disallow mixed binary operators. + * @author Toru Nagashima + */ + +"use strict"; + +//------------------------------------------------------------------------------ +// Requirements +//------------------------------------------------------------------------------ + +const astUtils = require("../ast-utils.js"); + +//------------------------------------------------------------------------------ +// Helpers +//------------------------------------------------------------------------------ + +const ARITHMETIC_OPERATORS = ["+", "-", "*", "/", "%", "**"]; +const BITWISE_OPERATORS = ["&", "|", "^", "~", "<<", ">>", ">>>"]; +const COMPARISON_OPERATORS = ["==", "!=", "===", "!==", ">", ">=", "<", "<="]; +const LOGICAL_OPERATORS = ["&&", "||"]; +const RELATIONAL_OPERATORS = ["in", "instanceof"]; +const ALL_OPERATORS = [].concat( + ARITHMETIC_OPERATORS, + BITWISE_OPERATORS, + COMPARISON_OPERATORS, + LOGICAL_OPERATORS, + RELATIONAL_OPERATORS +); +const DEFAULT_GROUPS = [ + ARITHMETIC_OPERATORS, + BITWISE_OPERATORS, + COMPARISON_OPERATORS, + LOGICAL_OPERATORS, + RELATIONAL_OPERATORS +]; +const TARGET_NODE_TYPE = /^(?:Binary|Logical)Expression$/; + +/** + * Normalizes options. + * + * @param {Object|undefined} options - A options object to normalize. + * @returns {Object} Normalized option object. + */ +function normalizeOptions(options) { + const hasGroups = (options && options.groups && options.groups.length > 0); + const groups = hasGroups ? options.groups : DEFAULT_GROUPS; + const allowSamePrecedence = (options && options.allowSamePrecedence) !== false; + + return { + groups, + allowSamePrecedence + }; +} + +/** + * Checks whether any group which includes both given operator exists or not. + * + * @param {Array.<string[]>} groups - A list of groups to check. + * @param {string} left - An operator. + * @param {string} right - Another operator. + * @returns {boolean} `true` if such group existed. + */ +function includesBothInAGroup(groups, left, right) { + return groups.some(group => group.indexOf(left) !== -1 && group.indexOf(right) !== -1); +} + +//------------------------------------------------------------------------------ +// Rule Definition +//------------------------------------------------------------------------------ + +module.exports = { + meta: { + docs: { + description: "disallow mixed binary operators", + category: "Stylistic Issues", + recommended: false + }, + schema: [ + { + type: "object", + properties: { + groups: { + type: "array", + items: { + type: "array", + items: { enum: ALL_OPERATORS }, + minItems: 2, + uniqueItems: true + }, + uniqueItems: true + }, + allowSamePrecedence: { + type: "boolean" + } + }, + additionalProperties: false + } + ] + }, + + create(context) { + const sourceCode = context.getSourceCode(); + const options = normalizeOptions(context.options[0]); + + /** + * Checks whether a given node should be ignored by options or not. + * + * @param {ASTNode} node - A node to check. This is a BinaryExpression + * node or a LogicalExpression node. This parent node is one of + * them, too. + * @returns {boolean} `true` if the node should be ignored. + */ + function shouldIgnore(node) { + const a = node; + const b = node.parent; + + return ( + !includesBothInAGroup(options.groups, a.operator, b.operator) || + ( + options.allowSamePrecedence && + astUtils.getPrecedence(a) === astUtils.getPrecedence(b) + ) + ); + } + + /** + * Checks whether the operator of a given node is mixed with parent + * node's operator or not. + * + * @param {ASTNode} node - A node to check. This is a BinaryExpression + * node or a LogicalExpression node. This parent node is one of + * them, too. + * @returns {boolean} `true` if the node was mixed. + */ + function isMixedWithParent(node) { + return ( + node.operator !== node.parent.operator && + !astUtils.isParenthesised(sourceCode, node) + ); + } + + /** + * Gets the operator token of a given node. + * + * @param {ASTNode} node - A node to check. This is a BinaryExpression + * node or a LogicalExpression node. + * @returns {Token} The operator token of the node. + */ + function getOperatorToken(node) { + return sourceCode.getTokenAfter(node.left, astUtils.isNotClosingParenToken); + } + + /** + * Reports both the operator of a given node and the operator of the + * parent node. + * + * @param {ASTNode} node - A node to check. This is a BinaryExpression + * node or a LogicalExpression node. This parent node is one of + * them, too. + * @returns {void} + */ + function reportBothOperators(node) { + const parent = node.parent; + const left = (parent.left === node) ? node : parent; + const right = (parent.left !== node) ? node : parent; + const message = + "Unexpected mix of '{{leftOperator}}' and '{{rightOperator}}'."; + const data = { + leftOperator: left.operator, + rightOperator: right.operator + }; + + context.report({ + node: left, + loc: getOperatorToken(left).loc.start, + message, + data + }); + context.report({ + node: right, + loc: getOperatorToken(right).loc.start, + message, + data + }); + } + + /** + * Checks between the operator of this node and the operator of the + * parent node. + * + * @param {ASTNode} node - A node to check. + * @returns {void} + */ + function check(node) { + if (TARGET_NODE_TYPE.test(node.parent.type) && + isMixedWithParent(node) && + !shouldIgnore(node) + ) { + reportBothOperators(node); + } + } + + return { + BinaryExpression: check, + LogicalExpression: check + }; + } +}; |