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, 116 insertions, 0 deletions

diff --git a/tools/node_modules/eslint/lib/rules/id-length.js b/tools/node_modules/eslint/lib/rules/id-length.js
new file mode 100644
index 0000000000..dad9c40649
--- /dev/null
+++ b/tools/node_modules/eslint/lib/rules/id-length.js
@@ -0,0 +1,116 @@
+/**
+ * @fileoverview Rule that warns when identifier names are shorter or longer
+ * than the values provided in configuration.
+ * @author Burak Yigit Kaya aka BYK
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+module.exports = {
+    meta: {
+        docs: {
+            description: "enforce minimum and maximum identifier lengths",
+            category: "Stylistic Issues",
+            recommended: false
+        },
+
+        schema: [
+            {
+                type: "object",
+                properties: {
+                    min: {
+                        type: "number"
+                    },
+                    max: {
+                        type: "number"
+                    },
+                    exceptions: {
+                        type: "array",
+                        uniqueItems: true,
+                        items: {
+                            type: "string"
+                        }
+                    },
+                    properties: {
+                        enum: ["always", "never"]
+                    }
+                },
+                additionalProperties: false
+            }
+        ]
+    },
+
+    create(context) {
+        const options = context.options[0] || {};
+        const minLength = typeof options.min !== "undefined" ? options.min : 2;
+        const maxLength = typeof options.max !== "undefined" ? options.max : Infinity;
+        const properties = options.properties !== "never";
+        const exceptions = (options.exceptions ? options.exceptions : [])
+            .reduce((obj, item) => {
+                obj[item] = true;
+
+                return obj;
+            }, {});
+
+        const SUPPORTED_EXPRESSIONS = {
+            MemberExpression: properties && function(parent) {
+                return !parent.computed && (
+
+                    // regular property assignment
+                    (parent.parent.left === parent && parent.parent.type === "AssignmentExpression" ||
+
+                    // or the last identifier in an ObjectPattern destructuring
+                    parent.parent.type === "Property" && parent.parent.value === parent &&
+                    parent.parent.parent.type === "ObjectPattern" && parent.parent.parent.parent.left === parent.parent.parent)
+                );
+            },
+            AssignmentPattern(parent, node) {
+                return parent.left === node;
+            },
+            VariableDeclarator(parent, node) {
+                return parent.id === node;
+            },
+            Property: properties && function(parent, node) {
+                return parent.key === node;
+            },
+            ImportDefaultSpecifier: true,
+            RestElement: true,
+            FunctionExpression: true,
+            ArrowFunctionExpression: true,
+            ClassDeclaration: true,
+            FunctionDeclaration: true,
+            MethodDefinition: true,
+            CatchClause: true
+        };
+
+        return {
+            Identifier(node) {
+                const name = node.name;
+                const parent = node.parent;
+
+                const isShort = name.length < minLength;
+                const isLong = name.length > maxLength;
+
+                if (!(isShort || isLong) || exceptions[name]) {
+                    return; // Nothing to report
+                }
+
+                const isValidExpression = SUPPORTED_EXPRESSIONS[parent.type];
+
+                if (isValidExpression && (isValidExpression === true || isValidExpression(parent, node))) {
+                    context.report({
+                        node,
+                        message: isShort
+                            ? "Identifier name '{{name}}' is too short (< {{min}})."
+                            : "Identifier name '{{name}}' is too long (> {{max}}).",
+                        data: { name, min: minLength, max: maxLength }
+                    });
+                }
+            }
+        };
+    }
+};