feat(object.has-key()): add checking the key in any object name.

object/_index.scss

@@ -2,6 +2,7 @@
 @forward 'object.create.function';
 @forward 'object.get-key.function';
 @forward 'object.get.function';
+@forward 'object.has-key.function';
 @forward 'object.keys.function';
 @forward 'object.last-id.function';
 @forward 'object.last-name.function';

object/_object.has-key.function.scss

@@ -0,0 +1,22 @@
+// Sass.
+@use 'sass:map';
+
+// Variables.
+@use 'object.var' as object;
+
+// Functions.
+@use 'object.get-key.function' as *;
+
+// Status: TODO: key
+// The `object.has-key()` function checks whether object in use has key.
+// @param `$key` Required key to check object in use has.
+// @arbitrary `$keys...` Additional keys to check nested key.
+// @returns The returned value is a `bool` indicating object in use has key.
+@function has-key($key, $keys...) {
+  @if type-of($key) == map {
+    @each $name, $key in $key {
+      @return map.has-key(object.$object, get-key($name, $key)...);
+    }
+  }
+  @return map.has-key(object.$object, get-key($key: $key)...);
+}

object/_object.spec.scss

@@ -139,6 +139,9 @@ $debug: object.merge(light, (object 1: 1), (object 2: 2));
 // @debug object.get();
 // @debug object.last-name();
 // @debug object.keys();
+// @debug object.has-key((theme: (light, theme color)));
+// @debug object.has-key(light, theme color);
+
 // @debug object.pick((light, dark color));
 
 // $debug: object.copy(light, (dark color, theme)); // DONE