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, 43 insertions, 0 deletions

diff --git a/tools/node_modules/eslint/lib/rules/no-new-symbol.js b/tools/node_modules/eslint/lib/rules/no-new-symbol.js
new file mode 100644
index 0000000000..5743a4748a
--- /dev/null
+++ b/tools/node_modules/eslint/lib/rules/no-new-symbol.js
@@ -0,0 +1,43 @@
+/**
+ * @fileoverview Rule to disallow use of the new operator with the `Symbol` object
+ * @author Alberto Rodríguez
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+module.exports = {
+    meta: {
+        docs: {
+            description: "disallow `new` operators with the `Symbol` object",
+            category: "ECMAScript 6",
+            recommended: true
+        },
+
+        schema: []
+    },
+
+    create(context) {
+
+        return {
+            "Program:exit"() {
+                const globalScope = context.getScope();
+                const variable = globalScope.set.get("Symbol");
+
+                if (variable && variable.defs.length === 0) {
+                    variable.references.forEach(ref => {
+                        const node = ref.identifier;
+
+                        if (node.parent && node.parent.type === "NewExpression") {
+                            context.report({ node, message: "`Symbol` cannot be called as a constructor." });
+                        }
+                    });
+                }
+            }
+        };
+
+    }
+};