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, 148 insertions, 0 deletions

diff --git a/tools/node_modules/eslint/lib/rules/max-depth.js b/tools/node_modules/eslint/lib/rules/max-depth.js
new file mode 100644
index 0000000000..74c13ffa9f
--- /dev/null
+++ b/tools/node_modules/eslint/lib/rules/max-depth.js
@@ -0,0 +1,148 @@
+/**
+ * @fileoverview A rule to set the maximum depth block can be nested in a function.
+ * @author Ian Christian Myers
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+module.exports = {
+    meta: {
+        docs: {
+            description: "enforce a maximum depth that blocks can be nested",
+            category: "Stylistic Issues",
+            recommended: false
+        },
+
+        schema: [
+            {
+                oneOf: [
+                    {
+                        type: "integer",
+                        minimum: 0
+                    },
+                    {
+                        type: "object",
+                        properties: {
+                            maximum: {
+                                type: "integer",
+                                minimum: 0
+                            },
+                            max: {
+                                type: "integer",
+                                minimum: 0
+                            }
+                        },
+                        additionalProperties: false
+                    }
+                ]
+            }
+        ]
+    },
+
+    create(context) {
+
+        //--------------------------------------------------------------------------
+        // Helpers
+        //--------------------------------------------------------------------------
+
+        const functionStack = [],
+            option = context.options[0];
+        let maxDepth = 4;
+
+        if (typeof option === "object" && option.hasOwnProperty("maximum") && typeof option.maximum === "number") {
+            maxDepth = option.maximum;
+        }
+        if (typeof option === "object" && option.hasOwnProperty("max") && typeof option.max === "number") {
+            maxDepth = option.max;
+        }
+        if (typeof option === "number") {
+            maxDepth = option;
+        }
+
+        /**
+         * When parsing a new function, store it in our function stack
+         * @returns {void}
+         * @private
+         */
+        function startFunction() {
+            functionStack.push(0);
+        }
+
+        /**
+         * When parsing is done then pop out the reference
+         * @returns {void}
+         * @private
+         */
+        function endFunction() {
+            functionStack.pop();
+        }
+
+        /**
+         * Save the block and Evaluate the node
+         * @param {ASTNode} node node to evaluate
+         * @returns {void}
+         * @private
+         */
+        function pushBlock(node) {
+            const len = ++functionStack[functionStack.length - 1];
+
+            if (len > maxDepth) {
+                context.report({ node, message: "Blocks are nested too deeply ({{depth}}).", data: { depth: len } });
+            }
+        }
+
+        /**
+         * Pop the saved block
+         * @returns {void}
+         * @private
+         */
+        function popBlock() {
+            functionStack[functionStack.length - 1]--;
+        }
+
+        //--------------------------------------------------------------------------
+        // Public API
+        //--------------------------------------------------------------------------
+
+        return {
+            Program: startFunction,
+            FunctionDeclaration: startFunction,
+            FunctionExpression: startFunction,
+            ArrowFunctionExpression: startFunction,
+
+            IfStatement(node) {
+                if (node.parent.type !== "IfStatement") {
+                    pushBlock(node);
+                }
+            },
+            SwitchStatement: pushBlock,
+            TryStatement: pushBlock,
+            DoWhileStatement: pushBlock,
+            WhileStatement: pushBlock,
+            WithStatement: pushBlock,
+            ForStatement: pushBlock,
+            ForInStatement: pushBlock,
+            ForOfStatement: pushBlock,
+
+            "IfStatement:exit": popBlock,
+            "SwitchStatement:exit": popBlock,
+            "TryStatement:exit": popBlock,
+            "DoWhileStatement:exit": popBlock,
+            "WhileStatement:exit": popBlock,
+            "WithStatement:exit": popBlock,
+            "ForStatement:exit": popBlock,
+            "ForInStatement:exit": popBlock,
+            "ForOfStatement:exit": popBlock,
+
+            "FunctionDeclaration:exit": endFunction,
+            "FunctionExpression:exit": endFunction,
+            "ArrowFunctionExpression:exit": endFunction,
+            "Program:exit": endFunction
+        };
+
+    }
+};