--- /dev/null
+/**
+ * @fileoverview Rule to enforce a maximum number of nested callbacks.
+ * @author Ian Christian Myers
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+module.exports = {
+ meta: {
+ type: "suggestion",
+
+ docs: {
+ description: "enforce a maximum depth that callbacks can be nested",
+ category: "Stylistic Issues",
+ recommended: false,
+ url: "https://eslint.org/docs/rules/max-nested-callbacks"
+ },
+
+ schema: [
+ {
+ oneOf: [
+ {
+ type: "integer",
+ minimum: 0
+ },
+ {
+ type: "object",
+ properties: {
+ maximum: {
+ type: "integer",
+ minimum: 0
+ },
+ max: {
+ type: "integer",
+ minimum: 0
+ }
+ },
+ additionalProperties: false
+ }
+ ]
+ }
+ ],
+ messages: {
+ exceed: "Too many nested callbacks ({{num}}). Maximum allowed is {{max}}."
+ }
+ },
+
+ create(context) {
+
+ //--------------------------------------------------------------------------
+ // Constants
+ //--------------------------------------------------------------------------
+ const option = context.options[0];
+ let THRESHOLD = 10;
+
+ if (
+ typeof option === "object" &&
+ (Object.prototype.hasOwnProperty.call(option, "maximum") || Object.prototype.hasOwnProperty.call(option, "max"))
+ ) {
+ THRESHOLD = option.maximum || option.max;
+ } else if (typeof option === "number") {
+ THRESHOLD = option;
+ }
+
+ //--------------------------------------------------------------------------
+ // Helpers
+ //--------------------------------------------------------------------------
+
+ const callbackStack = [];
+
+ /**
+ * Checks a given function node for too many callbacks.
+ * @param {ASTNode} node The node to check.
+ * @returns {void}
+ * @private
+ */
+ function checkFunction(node) {
+ const parent = node.parent;
+
+ if (parent.type === "CallExpression") {
+ callbackStack.push(node);
+ }
+
+ if (callbackStack.length > THRESHOLD) {
+ const opts = { num: callbackStack.length, max: THRESHOLD };
+
+ context.report({ node, messageId: "exceed", data: opts });
+ }
+ }
+
+ /**
+ * Pops the call stack.
+ * @returns {void}
+ * @private
+ */
+ function popStack() {
+ callbackStack.pop();
+ }
+
+ //--------------------------------------------------------------------------
+ // Public API
+ //--------------------------------------------------------------------------
+
+ return {
+ ArrowFunctionExpression: checkFunction,
+ "ArrowFunctionExpression:exit": popStack,
+
+ FunctionExpression: checkFunction,
+ "FunctionExpression:exit": popStack
+ };
+
+ }
+};