Repository: jquery/jquery
File: src/css.js (JavaScript)

Code before:
			jQuery.css( elem, "boxSizing", false, styles ) === "border-box",
		valueIsBorderBox = isBorderBox,

		val = curCSS( elem, dimension, styles ),
		offsetProp = "offset" + dimension[ 0 ].toUpperCase() + dimension.slice( 1 );

	// Support: Firefox <=54
	// Return a confounding non-pixel value or feign ignorance, as appropriate.
	if ( rnumnonpx.test( val ) ) {
		if ( !extra ) {
			return val;
		}
		val = "auto";
	}


	// Fall back to offsetWidth/offsetHeight when value is "auto"
	// This happens for inline elements with no explicit setting (gh-3571)
	// Support: Android <=4.1 - 4.3 only
	// Also use offsetWidth/offsetHeight for misreported inline dimensions (gh-3602)
	// Support: IE 9-11 only
	// Also use offsetWidth/offsetHeight for when box sizing is unreliable
	// We use getClientRects() to check for hidden/disconnected.
	// In those cases, the computed value can be trusted to be border-box
	if ( ( !support.boxSizingReliable() &&
		jQuery.css( elem, "boxSizing", false, styles ) === "border-box" ||
		val === "auto" ||
		!parseFloat( val ) && jQuery.css( elem, "display", false, styles ) === "inline" ) &&
		elem.getClientRects().length ) {

		isBorderBox = jQuery.css( elem, "boxSizing", false, styles ) === "border-box";

		// Where available, offsetWidth/offsetHeight approximate border box dimensions.
		// Where not available (e.g., SVG), assume unreliable box-sizing and interpret the
		// retrieved value as a content box dimension.
		valueIsBorderBox = offsetProp in elem;
		if ( valueIsBorderBox ) {
			val = elem[ offsetProp ];
		}
	}

	// Normalize "" and auto
	val = parseFloat( val ) || 0;

	// Adjust for the element's box model
	return ( val +
		boxModelAdjustment(
			elem,
			dimension,
			extra || ( isBorderBox ? "border" : "content" ),
			valueIsBorderBox,

Review comment (suggestion):
You may get a size reduction by turning this bare condition into an assignment, matching its other two appearances.
```suggestion
		(isBorderBox = jQuery.css( elem, "boxSizing", false, styles ) === "border-box") ||
```

Code after:
			jQuery.css( elem, "boxSizing", false, styles ) === "border-box",
		valueIsBorderBox = isBorderBox,

		val = curCSS( elem, dimension, styles ),
		offsetProp = "offset" + dimension[ 0 ].toUpperCase() + dimension.slice( 1 );

	// Support: Firefox <=54
	// Return a confounding non-pixel value or feign ignorance, as appropriate.
	if ( rnumnonpx.test( val ) ) {
		if ( !extra ) {
			return val;
		}
		val = "auto";
	}


	// Fall back to offsetWidth/offsetHeight when value is "auto"
	// This happens for inline elements with no explicit setting (gh-3571)
	// Support: Android <=4.1 - 4.3 only
	// Also use offsetWidth/offsetHeight for misreported inline dimensions (gh-3602)
	// Support: IE 9-11 only
	// Also use offsetWidth/offsetHeight for when box sizing is unreliable
	// We use getClientRects() to check for hidden/disconnected.
	// In those cases, the computed value can be trusted to be border-box
	if ( ( !support.boxSizingReliable() && isBorderBox ||
		val === "auto" ||
		!parseFloat( val ) && jQuery.css( elem, "display", false, styles ) === "inline" ) &&
		elem.getClientRects().length ) {

		isBorderBox = jQuery.css( elem, "boxSizing", false, styles ) === "border-box";

		// Where available, offsetWidth/offsetHeight approximate border box dimensions.
		// Where not available (e.g., SVG), assume unreliable box-sizing and interpret the
		// retrieved value as a content box dimension.
		valueIsBorderBox = offsetProp in elem;
		if ( valueIsBorderBox ) {
			val = elem[ offsetProp ];
		}
	}

	// Normalize "" and auto
	val = parseFloat( val ) || 0;

	// Adjust for the element's box model
	return ( val +
		boxModelAdjustment(
			elem,
			dimension,
			extra || ( isBorderBox ? "border" : "content" ),
			valueIsBorderBox,
			styles,