thingies

parts/3/phonebookBackend/node_modules/eslint/lib/shared/deep-merge-arrays.js

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+/**
+ * @fileoverview Applies default rule options
+ * @author JoshuaKGoldberg
+ */
+
+"use strict";
+
+/**
+ * Check if the variable contains an object strictly rejecting arrays
+ * @param {unknown} value an object
+ * @returns {boolean} Whether value is an object
+ */
+function isObjectNotArray(value) {
+	return typeof value === "object" && value !== null && !Array.isArray(value);
+}
+
+/**
+ * Deeply merges second on top of first, creating a new {} object if needed.
+ * @param {T} first Base, default value.
+ * @param {U} second User-specified value.
+ * @returns {T | U | (T & U)} Merged equivalent of second on top of first.
+ */
+function deepMergeObjects(first, second) {
+	if (second === void 0) {
+		return first;
+	}
+
+	if (!isObjectNotArray(first) || !isObjectNotArray(second)) {
+		return second;
+	}
+
+	const result = { ...first, ...second };
+
+	for (const key of Object.keys(second)) {
+		if (Object.prototype.propertyIsEnumerable.call(first, key)) {
+			result[key] = deepMergeObjects(first[key], second[key]);
+		}
+	}
+
+	return result;
+}
+
+/**
+ * Deeply merges second on top of first, creating a new [] array if needed.
+ * @param {T[]} first Base, default values.
+ * @param {U[]} second User-specified values.
+ * @returns {(T | U | (T & U))[]} Merged equivalent of second on top of first.
+ */
+function deepMergeArrays(first, second) {
+	if (!first || !second) {
+		return second || first || [];
+	}
+
+	return [
+		...first.map((value, i) =>
+			deepMergeObjects(value, i < second.length ? second[i] : void 0),
+		),
+		...second.slice(first.length),
+	];
+}
+
+module.exports = { deepMergeArrays };