feat: properly handle arrays

src/index.ts

@@ -8,14 +8,18 @@ import { deepMerge } from './utils'
  *
  * @param {object} options - The configuration options.
  * @param {string} options.name - The name of the configuration file.
- * @param {string} [options.cwd] - The current working directory. If not provided, defaults to the current process's working directory.
+ * @param {string} [options.cwd] - The current working directory.
  * @param {T} options.defaultConfig - The default configuration.
- * @returns {Promise<T>} The merged configuration object.
+ * @returns {Promise<T>} The merged configuration.
  * @example ```ts
- * // imports from example.config.{ts,js} and merges with default config
- * await loadConfig({ name: 'example', defaultConfig: { foo: 'bar' } })
+ * // Merges arrays if both configs are arrays, otherwise does object deep merge
+ * await loadConfig({
+ *   name: 'example',
+ *   defaultConfig: [{ foo: 'bar' }]
+ * })
+ * ```
  */
-export async function loadConfig<T extends Record<string, unknown>>({ name, cwd, defaultConfig }: Config<T>): Promise<T> {
+export async function loadConfig<T>({ name, cwd, defaultConfig }: Config<T>): Promise<T> {
   const configPath = resolve(cwd || process.cwd(), `${name}.config`)
 
   try {

src/utils.ts

@@ -1,25 +1,37 @@
 /**
- * Deep merge objects
+ * Deep merge objects or arrays
  *
- * @param target - The target object
- * @param sources - The source objects
- * @returns The merged object
- * @example deepMerge({ foo: 'bar' }, { bar: 'baz' }) // { foo: 'bar', bar: 'baz' }
+ * @param target - The target object or array
+ * @param sources - The source objects or arrays
+ * @returns The merged result
  */
-export function deepMerge<T extends object>(target: T, ...sources: Array<Partial<T>>): T {
+export function deepMerge<T>(target: T, ...sources: Partial<T>[]): T {
   if (!sources.length)
     return target
 
   const source = sources.shift()
+  if (!source)
+    return target
+
+  if (Array.isArray(target) && Array.isArray(source)) {
+    // If both are arrays, concatenate them
+    return [...target, ...source] as T
+  }
 
   if (isObject(target) && isObject(source)) {
     for (const key in source) {
       if (Object.prototype.hasOwnProperty.call(source, key)) {
         const sourceValue = source[key]
-        if (isObject(sourceValue) && isObject(target[key])) {
-          target[key] = deepMerge(target[key] as any, sourceValue as any)
+        if (Array.isArray(sourceValue) && Array.isArray((target as any)[key])) {
+          // Merge arrays within objects
+          (target as any)[key] = [...(target as any)[key], ...sourceValue]
+        }
+        else if (isObject(sourceValue) && isObject((target as any)[key])) {
+          // Deep merge nested objects
+          (target as any)[key] = deepMerge((target as any)[key], sourceValue)
         }
         else {
+          // Replace primitive values and objects/arrays that don't match in type
           (target as any)[key] = sourceValue
         }
       }