Issue #7: Refactor input validation code

Check <health card, province> pair that was already encountered on a previous line

guids-generator.html

@@ -268,6 +268,15 @@
             return HC_VALIDATOR[province](value, dob) || HC_VALIDATOR['CA'](value);
         }
 
+        // For any line check previously enered lines that contains a <health card, province> pair
+        let checkDuplicates = (line, healthCard, province, postProcessed, index) => {
+            let duplicates = postProcessed.filter( item => (item.healthCard == healthCard && item.province == province) );
+            if (duplicates.length > 0) {
+                return {"error" : province +  " health card number " + line.trim().split(/[\t,]+/)[0] + " has already been entered on line " + index + " with a different date of birth"};
+            }
+            return {};
+        }
+
         // Input validation and sanitising
         let validate  = () => {
             let value = binput;
@@ -322,8 +331,15 @@
                     info[0] = healthCard;
                 }
 
+                // Check duplicated <health card, province> pair
+                let duplicates = checkDuplicates(line, healthCard, province, postProcessed, index);
+                if (duplicates.error) {
+                    postProcessed.push({"line" : line, "index": index, "value": duplicates.error, "isError": true});
+                    continue;
+                }
+
                 // If the input is found valid, concatenate the post-processed health card number and date of birth and generate the GUID
-                postProcessed.push({"line" : line, "index": index, "value": info[0] + info[2]});
+                postProcessed.push({"line" : line, "index": index, "healthCard": healthCard, "province": province, "value": info[0] + info[2]});
             }
 
             setValidatedData(postProcessed);