--- /dev/null
+/**
+ * @fileoverview Disallow Labeled Statements
+ * @author Nicholas C. Zakas
+ */
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const astUtils = require("./utils/ast-utils");
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+module.exports = {
+ meta: {
+ type: "suggestion",
+
+ docs: {
+ description: "disallow labeled statements",
+ category: "Best Practices",
+ recommended: false,
+ url: "https://eslint.org/docs/rules/no-labels"
+ },
+
+ schema: [
+ {
+ type: "object",
+ properties: {
+ allowLoop: {
+ type: "boolean",
+ default: false
+ },
+ allowSwitch: {
+ type: "boolean",
+ default: false
+ }
+ },
+ additionalProperties: false
+ }
+ ],
+
+ messages: {
+ unexpectedLabel: "Unexpected labeled statement.",
+ unexpectedLabelInBreak: "Unexpected label in break statement.",
+ unexpectedLabelInContinue: "Unexpected label in continue statement."
+ }
+ },
+
+ create(context) {
+ const options = context.options[0];
+ const allowLoop = options && options.allowLoop;
+ const allowSwitch = options && options.allowSwitch;
+ let scopeInfo = null;
+
+ /**
+ * Gets the kind of a given node.
+ * @param {ASTNode} node A node to get.
+ * @returns {string} The kind of the node.
+ */
+ function getBodyKind(node) {
+ if (astUtils.isLoop(node)) {
+ return "loop";
+ }
+ if (node.type === "SwitchStatement") {
+ return "switch";
+ }
+ return "other";
+ }
+
+ /**
+ * Checks whether the label of a given kind is allowed or not.
+ * @param {string} kind A kind to check.
+ * @returns {boolean} `true` if the kind is allowed.
+ */
+ function isAllowed(kind) {
+ switch (kind) {
+ case "loop": return allowLoop;
+ case "switch": return allowSwitch;
+ default: return false;
+ }
+ }
+
+ /**
+ * Checks whether a given name is a label of a loop or not.
+ * @param {string} label A name of a label to check.
+ * @returns {boolean} `true` if the name is a label of a loop.
+ */
+ function getKind(label) {
+ let info = scopeInfo;
+
+ while (info) {
+ if (info.label === label) {
+ return info.kind;
+ }
+ info = info.upper;
+ }
+
+ /* istanbul ignore next: syntax error */
+ return "other";
+ }
+
+ //--------------------------------------------------------------------------
+ // Public
+ //--------------------------------------------------------------------------
+
+ return {
+ LabeledStatement(node) {
+ scopeInfo = {
+ label: node.label.name,
+ kind: getBodyKind(node.body),
+ upper: scopeInfo
+ };
+ },
+
+ "LabeledStatement:exit"(node) {
+ if (!isAllowed(scopeInfo.kind)) {
+ context.report({
+ node,
+ messageId: "unexpectedLabel"
+ });
+ }
+
+ scopeInfo = scopeInfo.upper;
+ },
+
+ BreakStatement(node) {
+ if (node.label && !isAllowed(getKind(node.label.name))) {
+ context.report({
+ node,
+ messageId: "unexpectedLabelInBreak"
+ });
+ }
+ },
+
+ ContinueStatement(node) {
+ if (node.label && !isAllowed(getKind(node.label.name))) {
+ context.report({
+ node,
+ messageId: "unexpectedLabelInContinue"
+ });
+ }
+ }
+ };
+
+ }
+};