Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.4.21)
// Compass (v1.0.3)
// ----

@mixin transition-base($properties...){
  // Свойство transition-property по-умолчанию равно значению all
  // т.е. запись transition: 250ms ease 0s; будет
  // эквивалентна записи transition: all 250ms ease 0s;
  transition: 250ms ease 0s;
  @if length($properties) > 0 {
    transition-property: $properties;
  }
}

.s1 {
  @include transition-base();
}
.s2 {
  @include transition-base(padding, color, border-color);
}

SassMeister-output.css

.s1 {
  transition: 250ms ease 0s;
}

.s2 {
  transition: 250ms ease 0s;
  transition-property: padding, color, border-color;
}