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, 141 insertions, 0 deletions

diff --git a/tools/node_modules/eslint/lib/rules/no-labels.js b/tools/node_modules/eslint/lib/rules/no-labels.js
new file mode 100644
index 0000000000..101092a667
--- /dev/null
+++ b/tools/node_modules/eslint/lib/rules/no-labels.js
@@ -0,0 +1,141 @@
+/**
+ * @fileoverview Disallow Labeled Statements
+ * @author Nicholas C. Zakas
+ */
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const astUtils = require("../ast-utils");
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+module.exports = {
+    meta: {
+        docs: {
+            description: "disallow labeled statements",
+            category: "Best Practices",
+            recommended: false
+        },
+
+        schema: [
+            {
+                type: "object",
+                properties: {
+                    allowLoop: {
+                        type: "boolean"
+                    },
+                    allowSwitch: {
+                        type: "boolean"
+                    }
+                },
+                additionalProperties: false
+            }
+        ]
+    },
+
+    create(context) {
+        const options = context.options[0];
+        const allowLoop = Boolean(options && options.allowLoop);
+        const allowSwitch = Boolean(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,
+                        message: "Unexpected labeled statement."
+                    });
+                }
+
+                scopeInfo = scopeInfo.upper;
+            },
+
+            BreakStatement(node) {
+                if (node.label && !isAllowed(getKind(node.label.name))) {
+                    context.report({
+                        node,
+                        message: "Unexpected label in break statement."
+                    });
+                }
+            },
+
+            ContinueStatement(node) {
+                if (node.label && !isAllowed(getKind(node.label.name))) {
+                    context.report({
+                        node,
+                        message: "Unexpected label in continue statement."
+                    });
+                }
+            }
+        };
+
+    }
+};