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, 143 insertions, 0 deletions

diff --git a/tools/node_modules/eslint/lib/rules/camelcase.js b/tools/node_modules/eslint/lib/rules/camelcase.js
new file mode 100644
index 0000000000..6fb1475b21
--- /dev/null
+++ b/tools/node_modules/eslint/lib/rules/camelcase.js
@@ -0,0 +1,143 @@
+/**
+ * @fileoverview Rule to flag non-camelcased identifiers
+ * @author Nicholas C. Zakas
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+module.exports = {
+    meta: {
+        docs: {
+            description: "enforce camelcase naming convention",
+            category: "Stylistic Issues",
+            recommended: false
+        },
+
+        schema: [
+            {
+                type: "object",
+                properties: {
+                    properties: {
+                        enum: ["always", "never"]
+                    }
+                },
+                additionalProperties: false
+            }
+        ]
+    },
+
+    create(context) {
+
+        //--------------------------------------------------------------------------
+        // Helpers
+        //--------------------------------------------------------------------------
+
+        // contains reported nodes to avoid reporting twice on destructuring with shorthand notation
+        const reported = [];
+        const ALLOWED_PARENT_TYPES = new Set(["CallExpression", "NewExpression"]);
+
+        /**
+         * Checks if a string contains an underscore and isn't all upper-case
+         * @param {string} name The string to check.
+         * @returns {boolean} if the string is underscored
+         * @private
+         */
+        function isUnderscored(name) {
+
+            // if there's an underscore, it might be A_CONSTANT, which is okay
+            return name.indexOf("_") > -1 && name !== name.toUpperCase();
+        }
+
+        /**
+         * Reports an AST node as a rule violation.
+         * @param {ASTNode} node The node to report.
+         * @returns {void}
+         * @private
+         */
+        function report(node) {
+            if (reported.indexOf(node) < 0) {
+                reported.push(node);
+                context.report({ node, message: "Identifier '{{name}}' is not in camel case.", data: { name: node.name } });
+            }
+        }
+
+        const options = context.options[0] || {};
+        let properties = options.properties || "";
+
+        if (properties !== "always" && properties !== "never") {
+            properties = "always";
+        }
+
+        return {
+
+            Identifier(node) {
+
+                /*
+                 * Leading and trailing underscores are commonly used to flag
+                 * private/protected identifiers, strip them
+                 */
+                const name = node.name.replace(/^_+|_+$/g, ""),
+                    effectiveParent = (node.parent.type === "MemberExpression") ? node.parent.parent : node.parent;
+
+                // MemberExpressions get special rules
+                if (node.parent.type === "MemberExpression") {
+
+                    // "never" check properties
+                    if (properties === "never") {
+                        return;
+                    }
+
+                    // Always report underscored object names
+                    if (node.parent.object.type === "Identifier" &&
+                            node.parent.object.name === node.name &&
+                            isUnderscored(name)) {
+                        report(node);
+
+                    // Report AssignmentExpressions only if they are the left side of the assignment
+                    } else if (effectiveParent.type === "AssignmentExpression" &&
+                            isUnderscored(name) &&
+                            (effectiveParent.right.type !== "MemberExpression" ||
+                            effectiveParent.left.type === "MemberExpression" &&
+                            effectiveParent.left.property.name === node.name)) {
+                        report(node);
+                    }
+
+                // Properties have their own rules
+                } else if (node.parent.type === "Property") {
+
+                    // "never" check properties
+                    if (properties === "never") {
+                        return;
+                    }
+
+                    if (node.parent.parent && node.parent.parent.type === "ObjectPattern" &&
+                            node.parent.key === node && node.parent.value !== node) {
+                        return;
+                    }
+
+                    if (isUnderscored(name) && !ALLOWED_PARENT_TYPES.has(effectiveParent.type)) {
+                        report(node);
+                    }
+
+                // Check if it's an import specifier
+                } else if (["ImportSpecifier", "ImportNamespaceSpecifier", "ImportDefaultSpecifier"].indexOf(node.parent.type) >= 0) {
+
+                    // Report only if the local imported identifier is underscored
+                    if (node.parent.local && node.parent.local.name === node.name && isUnderscored(name)) {
+                        report(node);
+                    }
+
+                // Report anything that is underscored that isn't a CallExpression
+                } else if (isUnderscored(name) && !ALLOWED_PARENT_TYPES.has(effectiveParent.type)) {
+                    report(node);
+                }
+            }
+
+        };
+
+    }
+};