1 files changed, 101 insertions, 0 deletions
diff --git a/tools/node_modules/eslint/lib/rules/no-redeclare.js b/tools/node_modules/eslint/lib/rules/no-redeclare.js
new file mode 100644
index 0000000000..ccb57003ed
--- /dev/null
+++ b/tools/node_modules/eslint/lib/rules/no-redeclare.js
@@ -0,0 +1,101 @@
+/**
+ * @fileoverview Rule to flag when the same variable is declared more then once.
+ * @author Ilya Volodin
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+module.exports = {
+    meta: {
+        docs: {
+            description: "disallow variable redeclaration",
+            category: "Best Practices",
+            recommended: true
+        },
+
+        schema: [
+            {
+                type: "object",
+                properties: {
+                    builtinGlobals: { type: "boolean" }
+                },
+                additionalProperties: false
+            }
+        ]
+    },
+
+    create(context) {
+        const options = {
+            builtinGlobals: Boolean(context.options[0] && context.options[0].builtinGlobals)
+        };
+
+        /**
+         * Find variables in a given scope and flag redeclared ones.
+         * @param {Scope} scope - An eslint-scope scope object.
+         * @returns {void}
+         * @private
+         */
+        function findVariablesInScope(scope) {
+            scope.variables.forEach(variable => {
+                const hasBuiltin = options.builtinGlobals && "writeable" in variable;
+                const count = (hasBuiltin ? 1 : 0) + variable.identifiers.length;
+
+                if (count >= 2) {
+                    variable.identifiers.sort((a, b) => a.range[1] - b.range[1]);
+
+                    for (let i = (hasBuiltin ? 0 : 1), l = variable.identifiers.length; i < l; i++) {
+                        context.report({ node: variable.identifiers[i], message: "'{{a}}' is already defined.", data: { a: variable.name } });
+                    }
+                }
+            });
+
+        }
+
+        /**
+         * Find variables in the current scope.
+         * @param {ASTNode} node - The Program node.
+         * @returns {void}
+         * @private
+         */
+        function checkForGlobal(node) {
+            const scope = context.getScope(),
+                parserOptions = context.parserOptions,
+                ecmaFeatures = parserOptions.ecmaFeatures || {};
+
+            // Nodejs env or modules has a special scope.
+            if (ecmaFeatures.globalReturn || node.sourceType === "module") {
+                findVariablesInScope(scope.childScopes[0]);
+            } else {
+                findVariablesInScope(scope);
+            }
+        }
+
+        /**
+         * Find variables in the current scope.
+         * @returns {void}
+         * @private
+         */
+        function checkForBlock() {
+            findVariablesInScope(context.getScope());
+        }
+
+        if (context.parserOptions.ecmaVersion >= 6) {
+            return {
+                Program: checkForGlobal,
+                BlockStatement: checkForBlock,
+                SwitchStatement: checkForBlock
+            };
+        }
+        return {
+            Program: checkForGlobal,
+            FunctionDeclaration: checkForBlock,
+            FunctionExpression: checkForBlock,
+            ArrowFunctionExpression: checkForBlock
+        };
+
+    }
+};