Prevent min constraint going negative #2695

assets/js/base/components/price-slider/constrain-range-slider-values.js

@@ -1,45 +1,53 @@
+const parseValid = ( value, fallback ) => {
+	const parsedValue =
+		typeof value === 'string' ? parseInt( value, 10 ) : value;
+
+	if ( ! Number.isFinite( parsedValue ) ) {
+		return fallback;
+	}
+
+	return parsedValue;
+};
+
 /**
  * Validate a min and max value for a range slider against defined constraints (min, max, step).
  *
  * @param {Array} values Array containing min and max values.
- * @param {number|null} min Min allowed value for the sliders.
- * @param {number|null} max Max allowed value for the sliders.
+ * @param {number|null} minAllowed Min allowed value for the sliders.
+ * @param {number|null} maxAllowed Max allowed value for the sliders.
  * @param {number} step Step value for the sliders.
  * @param {boolean} isMin Whether we're currently interacting with the min range slider or not, so we update the correct values.
  * @return {Array} Validated and updated min/max values that fit within the range slider constraints.
  */
 export const constrainRangeSliderValues = (
 	values,
-	min,
-	max,
+	minAllowed,
+	maxAllowed,
 	step = 1,
 	isMin = false
 ) => {
-	let minValue = parseInt( values[ 0 ], 10 );
-	let maxValue = parseInt( values[ 1 ], 10 );
+	const hasMinConstraint = Number.isFinite( minAllowed );
+	const hasMaxConstraint = Number.isFinite( maxAllowed );
+	const minConstraint = minAllowed || 0;
+	const maxConstraint = maxAllowed || step;
 
-	if ( ! Number.isFinite( minValue ) ) {
-		minValue = min || 0;
-	}
-
-	if ( ! Number.isFinite( maxValue ) ) {
-		maxValue = max || step;
-	}
+	let minValue = parseValid( values[ 0 ], minConstraint );
+	let maxValue = parseValid( values[ 1 ], maxConstraint );
 
-	if ( Number.isFinite( min ) && min > minValue ) {
-		minValue = min;
+	if ( hasMinConstraint && minConstraint > minValue ) {
+		minValue = minConstraint;
 	}
 
-	if ( Number.isFinite( max ) && max <= minValue ) {
-		minValue = max - step;
+	if ( hasMaxConstraint && maxConstraint <= minValue ) {
+		minValue = maxConstraint - step;
 	}
 
-	if ( Number.isFinite( min ) && min >= maxValue ) {
-		maxValue = min + step;
+	if ( hasMinConstraint && minConstraint >= maxValue ) {
+		maxValue = minConstraint + step;
 	}
 
-	if ( Number.isFinite( max ) && max < maxValue ) {
-		maxValue = max;
+	if ( hasMaxConstraint && maxConstraint < maxValue ) {
+		maxValue = maxConstraint;
 	}
 
 	if ( ! isMin && minValue >= maxValue ) {
@@ -50,5 +58,9 @@ export const constrainRangeSliderValues = (
 		maxValue = minValue + step;
 	}
 
+	if ( minValue < 0 ) {
+		minValue = 0;
+	}
+
 	return [ minValue, maxValue ];
 };