feat: support array push syntax

Author: pi0

README.md

@@ -43,6 +43,12 @@ db.enabled=true
 update({ 'db.enabled': true }) // or update(..., { name: '.conf' })
 ```
 
+Push to an array:
+
+```ts
+update({ 'modules[]': 'test' })
+```
+
 **Read/Write config:**
 
 ```ts
@@ -83,6 +89,8 @@ It means that you can use `.` for keys to define objects. Some examples:
 
 **Note:** If you use keys that can override like `x=` and `x.y=`, you can disable this feature by passing `flat: true` option.
 
+**Tip:** You can use keys ending with `[]` to push to an array like `test[]=A`
+
 ## Native Values
 
 RC uses [destr](https://www.npmjs.com/package/destr) to convert values into native javascript values.

src/index.ts

@@ -40,8 +40,20 @@ export function parse (contents: string, options?: RCOptions): RC {
 
     // Key
     const key = match[1]
-    if (!key || key === '__proto__' || key === 'constructor') { continue }
-    config[key] = destr(match[2].trim() /* val */)
+
+    if (!key || key === '__proto__' || key === 'constructor') {
+      continue
+    }
+
+    const val = destr(match[2].trim() /* val */)
+
+    if (key.endsWith('[]')) {
+      const nkey = key.substr(0, key.length - 2)
+      config[nkey] = (config[nkey] || []).concat(val)
+      continue
+    }
+
+    config[key] = val
   }
 
   return options?.flat ? config : unflatten(config, { overwrite: true })

test/index.test.ts

@@ -53,4 +53,15 @@ describe('rc', () => {
     update(obj, { flat: true, name: '.conf2' })
     expect(read({ flat: true, name: '.conf2' })).toMatchObject(obj)
   })
+
+  test('Parse indexless arrays', () => {
+    expect(parse(`
+      x.foo[]=A
+      x.foo[]=B
+    `)).toMatchObject({
+      x: {
+        foo: ['A', 'B']
+      }
+    })
+  })
 })