refactor(indicator.remove()): remove indicator from string.

Author: sciborrudnicki

variant/indicator/_indicator.remove.function.scss

@@ -12,21 +12,31 @@
 // @returns
 @function remove($item, $indicator) {
   $i: 1;
-  $item: remove.value($item, '+');
-  @each $value in $item {
-    @if type-of($value) == string {
-      $item: list.set-nth($item, $i, string.replace(#{$value}, all, $indicator, ''));
-    } @else if type-of($value) == list {
-      $j: 1;
-      @each $v in $value {
-        $value: list.set-nth($value, $j, string.replace(#{$v}, all, $indicator, ''));
-        $j: $j + 1;
+  @if type-of($item) == string {
+    @if string.index($item, $indicator) {
+      $item: string.slice($item, 2);
+    }
+  } @else {
+    @each $value in $item {
+      @if type-of($value) == string {
+        $item: list.set-nth($item, $i, string.replace(#{$value}, all, $indicator, ''));
+      } @else if type-of($value) == list {
+        $j: 1;
+        @each $v in $value {
+          $value: list.set-nth($value, $j, string.replace(#{$v}, all, $indicator, ''));
+          $j: $j + 1;
+        }
+
+        $item: list.set-nth($item, $i, $value);
       }
 
-      $item: list.set-nth($item, $i, $value);
+      $i: $i + 1;
     }
-
-    $i: $i + 1;
   }
   @return $item;
 }
+
+// Examples.
+// @debug remove(+background, '+');
+// @debug remove(+bg, '+');
+// @debug type-of(remove(+bg, '+'));