--- /dev/null
+/**
+ * @fileoverview Rule to disallow mixed binary operators.
+ * @author Toru Nagashima
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const astUtils = require("./utils/ast-utils.js");
+
+//------------------------------------------------------------------------------
+// Helpers
+//------------------------------------------------------------------------------
+
+const ARITHMETIC_OPERATORS = ["+", "-", "*", "/", "%", "**"];
+const BITWISE_OPERATORS = ["&", "|", "^", "~", "<<", ">>", ">>>"];
+const COMPARISON_OPERATORS = ["==", "!=", "===", "!==", ">", ">=", "<", "<="];
+const LOGICAL_OPERATORS = ["&&", "||"];
+const RELATIONAL_OPERATORS = ["in", "instanceof"];
+const TERNARY_OPERATOR = ["?:"];
+const ALL_OPERATORS = [].concat(
+ ARITHMETIC_OPERATORS,
+ BITWISE_OPERATORS,
+ COMPARISON_OPERATORS,
+ LOGICAL_OPERATORS,
+ RELATIONAL_OPERATORS,
+ TERNARY_OPERATOR
+);
+const DEFAULT_GROUPS = [
+ ARITHMETIC_OPERATORS,
+ BITWISE_OPERATORS,
+ COMPARISON_OPERATORS,
+ LOGICAL_OPERATORS,
+ RELATIONAL_OPERATORS
+];
+const TARGET_NODE_TYPE = /^(?:Binary|Logical|Conditional)Expression$/u;
+
+/**
+ * Normalizes options.
+ * @param {Object|undefined} options A options object to normalize.
+ * @returns {Object} Normalized option object.
+ */
+function normalizeOptions(options = {}) {
+ const hasGroups = options.groups && options.groups.length > 0;
+ const groups = hasGroups ? options.groups : DEFAULT_GROUPS;
+ const allowSamePrecedence = 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);
+}
+
+/**
+ * Checks whether the given node is a conditional expression and returns the test node else the left node.
+ * @param {ASTNode} node A node which can be a BinaryExpression or a LogicalExpression node.
+ * This parent node can be BinaryExpression, LogicalExpression
+ * , or a ConditionalExpression node
+ * @returns {ASTNode} node the appropriate node(left or test).
+ */
+function getChildNode(node) {
+ return node.type === "ConditionalExpression" ? node.test : node.left;
+}
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+module.exports = {
+ meta: {
+ type: "suggestion",
+
+ docs: {
+ description: "disallow mixed binary operators",
+ category: "Stylistic Issues",
+ recommended: false,
+ url: "https://eslint.org/docs/rules/no-mixed-operators"
+ },
+
+ schema: [
+ {
+ type: "object",
+ properties: {
+ groups: {
+ type: "array",
+ items: {
+ type: "array",
+ items: { enum: ALL_OPERATORS },
+ minItems: 2,
+ uniqueItems: true
+ },
+ uniqueItems: true
+ },
+ allowSamePrecedence: {
+ type: "boolean",
+ default: true
+ }
+ },
+ 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.type === "ConditionalExpression" ? "?:" : 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)
+ );
+ }
+
+ /**
+ * Checks whether the operator of a given node is mixed with a
+ * conditional expression.
+ * @param {ASTNode} node A node to check. This is a conditional
+ * expression node
+ * @returns {boolean} `true` if the node was mixed.
+ */
+ function isMixedWithConditionalParent(node) {
+ return !astUtils.isParenthesised(sourceCode, node) && !astUtils.isParenthesised(sourceCode, node.test);
+ }
+
+ /**
+ * 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(getChildNode(node), 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 = (getChildNode(parent) === node) ? node : parent;
+ const right = (getChildNode(parent) !== 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,
+ message,
+ data
+ });
+ context.report({
+ node: right,
+ loc: getOperatorToken(right).loc,
+ 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)) {
+ if (node.parent.type === "ConditionalExpression" && !shouldIgnore(node) && isMixedWithConditionalParent(node.parent)) {
+ reportBothOperators(node);
+ } else {
+ if (TARGET_NODE_TYPE.test(node.parent.type) &&
+ isMixedWithParent(node) &&
+ !shouldIgnore(node)
+ ) {
+ reportBothOperators(node);
+ }
+ }
+ }
+
+ }
+
+ return {
+ BinaryExpression: check,
+ LogicalExpression: check
+
+ };
+ }
+};
projects / dotfiles / .git / blobdiff