Merge pull request #2261 from IBMa/dev-2219

fix(engine): Issues related to `<elements>` made invisible with clip-path

Author: philljenkins

accessibility-checker-engine/src/v4/util/CSSUtil.ts

@@ -477,7 +477,8 @@ export class CSSUtil {
      * @return value in pixels
      */
     public static convertValue2Pixels(unit, unitValue, elem) {
-        if (unitValue == 0) return 0;
+        if (unitValue === 0) return 0;
+        if (!unit) unit = "px";
         const supportedUnits = {
             // absolute unit
             px: (value) => value,
@@ -511,7 +512,7 @@ export class CSSUtil {
                     getComputedStyle(elem).getPropertyValue("font-size")
                 ),
         };
-
+        
         if (unit in supportedUnits) return supportedUnits[unit](unitValue);
 
         return null;
@@ -863,4 +864,25 @@ export class CSSUtil {
         return null;
     }
 
+    /**
+     * return an array [value, Unit] from a value-unit combo string
+     * @param valueUnitCombo, such as 20px, 2rem 
+     * @returns 
+     */
+    public static getValueUnitPair(valueUnitCombo) {
+        if (!valueUnitCombo) return null;
+
+        if (Number.isInteger(valueUnitCombo)) return ["px", valueUnitCombo];
+
+        const value = parseInt(valueUnitCombo);
+        if (isNaN(value)) return null;
+
+        valueUnitCombo = valueUnitCombo.trim().toLowerCase();
+        let match = valueUnitCombo.trim().match(/([a-z]+)$/);
+        let unit = 'px';
+        if (match) unit = match[1];
+        
+        return [unit, value];
+    }
+
 }