1 files changed, 140 insertions, 0 deletions
diff --git a/tools/node_modules/eslint/lib/rules/no-extra-label.js b/tools/node_modules/eslint/lib/rules/no-extra-label.js
new file mode 100644
index 0000000000..b89267de93
--- /dev/null
+++ b/tools/node_modules/eslint/lib/rules/no-extra-label.js
@@ -0,0 +1,140 @@
+/**
+ * @fileoverview Rule to disallow unnecessary labels
+ * @author Toru Nagashima
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const astUtils = require("../ast-utils");
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+module.exports = {
+    meta: {
+        docs: {
+            description: "disallow unnecessary labels",
+            category: "Best Practices",
+            recommended: false
+        },
+
+        schema: [],
+
+        fixable: "code"
+    },
+
+    create(context) {
+        const sourceCode = context.getSourceCode();
+        let scopeInfo = null;
+
+        /**
+         * Creates a new scope with a breakable statement.
+         *
+         * @param {ASTNode} node - A node to create. This is a BreakableStatement.
+         * @returns {void}
+         */
+        function enterBreakableStatement(node) {
+            scopeInfo = {
+                label: node.parent.type === "LabeledStatement" ? node.parent.label : null,
+                breakable: true,
+                upper: scopeInfo
+            };
+        }
+
+        /**
+         * Removes the top scope of the stack.
+         *
+         * @returns {void}
+         */
+        function exitBreakableStatement() {
+            scopeInfo = scopeInfo.upper;
+        }
+
+        /**
+         * Creates a new scope with a labeled statement.
+         *
+         * This ignores it if the body is a breakable statement.
+         * In this case it's handled in the `enterBreakableStatement` function.
+         *
+         * @param {ASTNode} node - A node to create. This is a LabeledStatement.
+         * @returns {void}
+         */
+        function enterLabeledStatement(node) {
+            if (!astUtils.isBreakableStatement(node.body)) {
+                scopeInfo = {
+                    label: node.label,
+                    breakable: false,
+                    upper: scopeInfo
+                };
+            }
+        }
+
+        /**
+         * Removes the top scope of the stack.
+         *
+         * This ignores it if the body is a breakable statement.
+         * In this case it's handled in the `exitBreakableStatement` function.
+         *
+         * @param {ASTNode} node - A node. This is a LabeledStatement.
+         * @returns {void}
+         */
+        function exitLabeledStatement(node) {
+            if (!astUtils.isBreakableStatement(node.body)) {
+                scopeInfo = scopeInfo.upper;
+            }
+        }
+
+        /**
+         * Reports a given control node if it's unnecessary.
+         *
+         * @param {ASTNode} node - A node. This is a BreakStatement or a
+         *      ContinueStatement.
+         * @returns {void}
+         */
+        function reportIfUnnecessary(node) {
+            if (!node.label) {
+                return;
+            }
+
+            const labelNode = node.label;
+
+            for (let info = scopeInfo; info !== null; info = info.upper) {
+                if (info.breakable || info.label && info.label.name === labelNode.name) {
+                    if (info.breakable && info.label && info.label.name === labelNode.name) {
+                        context.report({
+                            node: labelNode,
+                            message: "This label '{{name}}' is unnecessary.",
+                            data: labelNode,
+                            fix: fixer => fixer.removeRange([sourceCode.getFirstToken(node).range[1], labelNode.range[1]])
+                        });
+                    }
+                    return;
+                }
+            }
+        }
+
+        return {
+            WhileStatement: enterBreakableStatement,
+            "WhileStatement:exit": exitBreakableStatement,
+            DoWhileStatement: enterBreakableStatement,
+            "DoWhileStatement:exit": exitBreakableStatement,
+            ForStatement: enterBreakableStatement,
+            "ForStatement:exit": exitBreakableStatement,
+            ForInStatement: enterBreakableStatement,
+            "ForInStatement:exit": exitBreakableStatement,
+            ForOfStatement: enterBreakableStatement,
+            "ForOfStatement:exit": exitBreakableStatement,
+            SwitchStatement: enterBreakableStatement,
+            "SwitchStatement:exit": exitBreakableStatement,
+            LabeledStatement: enterLabeledStatement,
+            "LabeledStatement:exit": exitLabeledStatement,
+            BreakStatement: reportIfUnnecessary,
+            ContinueStatement: reportIfUnnecessary
+        };
+    }
+};