fix(igxMask): Correct cursor position when typing - master (#12515)

* fix(igxMask): Correct cursor position when typing

* fix(igxMask): additional check if the maskedValue has been updated

Author: georgianastasov

projects/igniteui-angular/src/lib/directives/mask/mask-parsing.service.ts

@@ -91,6 +91,7 @@ export class MaskParsingService {
         const chars = Array.from(value);
         let cursor = start;
         end = Math.min(end, maskedValue.length);
+        let initialMaskedValue = maskedValue;
 
         for (let i = start; i < end || (chars.length && i < maskedValue.length); i++) {
             if (literalsPositions.indexOf(i) !== -1) {
@@ -114,10 +115,21 @@ export class MaskParsingService {
             maskedValue = this.replaceCharAt(maskedValue, i, char);
         }
 
-        if (Math.abs(end - start) >= 1) {
-            // set cursor to be max between last cursor pos and the calculated `end`
-            // since on `delete` the cursor should move forward
-            cursor = Math.max(cursor, end);
+        if (value.length <= 1) {
+            let isDelete = false;
+            cursor = start;
+            for (let i = 0; i < literalsPositions.length; i++) {
+                if (value === '') {
+                    // on `delete` the cursor should move forward
+                    cursor = Math.max(cursor, end);
+                    isDelete = true;
+                } else if (cursor === literalsPositions[i]) {
+                    cursor = literalsPositions[i] + 1;
+                }
+            }
+            if (!isDelete && initialMaskedValue !== maskedValue) {
+                cursor++;
+            }
         }
 
         return { value: maskedValue, end: cursor};