Mini Shell

// ==========================================================================
// Breakpoint Mixin
// See https://wpcalypso.wordpress.com/devdocs/docs/coding-guidelines/css.md#media-queries
// ==========================================================================

$breakpoints: 480px, 660px, 960px, 1040px; // Think very carefully before adding a new breakpoint

@mixin breakpoint( $size ){
	@if type-of($size) == string {
	  $approved-value: 0;
		@each $breakpoint in $breakpoints {
			$and-larger: ">" + $breakpoint;
			$and-smaller: "<" + $breakpoint;

			@if $size == $and-smaller {
				$approved-value: 1;
				@media ( max-width: $breakpoint ) {
					@content;
				}
			}
			@else {
				@if $size == $and-larger {
					$approved-value: 2;
					@media ( min-width: $breakpoint + 1 ) {
						@content;
					}
				}
				@else {
					@each $breakpoint-end in $breakpoints {
						$range: $breakpoint + "-" + $breakpoint-end;
						@if $size == $range {
							$approved-value: 3;
							@media ( min-width: $breakpoint + 1 ) and ( max-width: $breakpoint-end ) {
								@content;
							}
						}
					}
				}
			}
		}
		@if $approved-value == 0 {
			$sizes: "";
			@each $breakpoint in $breakpoints {
				$sizes: $sizes + " " + $breakpoint;
			}
			// TODO - change this to use @error, when it is supported by node-sass
			@warn "ERROR in breakpoint( #{ $size } ): You can only use these sizes[ #{$sizes} ] using the following syntax [ <#{ nth( $breakpoints, 1 ) } >#{ nth( $breakpoints, 1 ) } #{ nth( $breakpoints, 1 ) }-#{ nth( $breakpoints, 2 ) } ]";
		}
	}
	@else {
		$sizes: "";
		@each $breakpoint in $breakpoints {
			$sizes: $sizes + " " + $breakpoint;
		}
		// TODO - change this to use @error, when it is supported by node-sass
		@warn "ERROR in breakpoint( #{ $size } ): Please wrap the breakpoint $size in parenthesis. You can use these sizes[ #{$sizes} ] using the following syntax [ <#{ nth( $breakpoints, 1 ) } >#{ nth( $breakpoints, 1 ) } #{ nth( $breakpoints, 1 ) }-#{ nth( $breakpoints, 2 ) } ]";
	}
}