tools: move eslint from tools to tools/node_modules

This is required because we need to add the babel-eslint dependency
and it has to be able to resolve "eslint".
babel-eslint is required to support future ES features such as async
iterators and import.meta.

Refs: https://github.com/nodejs/node/pull/17755
PR-URL: https://github.com/nodejs/node/pull/17820
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>

1 files changed, 69 insertions, 0 deletions

diff --git a/tools/node_modules/eslint/lib/rules/no-label-var.js b/tools/node_modules/eslint/lib/rules/no-label-var.js
new file mode 100644
index 0000000000..954066aef3
--- /dev/null
+++ b/tools/node_modules/eslint/lib/rules/no-label-var.js
@@ -0,0 +1,69 @@
+/**
+ * @fileoverview Rule to flag labels that are the same as an identifier
+ * @author Ian Christian Myers
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const astUtils = require("../ast-utils");
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+module.exports = {
+    meta: {
+        docs: {
+            description: "disallow labels that share a name with a variable",
+            category: "Variables",
+            recommended: false
+        },
+
+        schema: []
+    },
+
+    create(context) {
+
+        //--------------------------------------------------------------------------
+        // Helpers
+        //--------------------------------------------------------------------------
+
+        /**
+         * Check if the identifier is present inside current scope
+         * @param {Object} scope current scope
+         * @param {string} name To evaluate
+         * @returns {boolean} True if its present
+         * @private
+         */
+        function findIdentifier(scope, name) {
+            return astUtils.getVariableByName(scope, name) !== null;
+        }
+
+        //--------------------------------------------------------------------------
+        // Public API
+        //--------------------------------------------------------------------------
+
+        return {
+
+            LabeledStatement(node) {
+
+                // Fetch the innermost scope.
+                const scope = context.getScope();
+
+                /*
+                 * Recursively find the identifier walking up the scope, starting
+                 * with the innermost scope.
+                 */
+                if (findIdentifier(scope, node.label.name)) {
+                    context.report({ node, message: "Found identifier with same name as label." });
+                }
+            }
+
+        };
+
+    }
+};