feat: extend conditional update item api

Author: mdsiddiq-till

src/mutation/updateItem.ts

@@ -38,6 +38,8 @@ const buildConditionExpressions = (
         expression += `${expressionName} ${operator} :val${i}_1 AND :val${i}_2`;
         attrValues[`:val${i}_1`] = value[0];
         attrValues[`:val${i}_2`] = value[1];
+      } else if (operator=== 'ATTRIBUTE_EXISTS' || operator === 'ATTRIBUTE_NOT_EXISTS') {
+        expression += `${operator.toLowerCase()}(${expressionName})`;
       } else {
         expression += `${expressionName} ${operator} :val${i}`;
         attrValues[`:val${i}`] = value;

src/query/queryBuilder.ts

@@ -39,6 +39,10 @@ export function keyOperatorLookup(
       return 'BEGINS_WITH';
     case 'exists':
       return 'EXISTS';
+    case 'attribute_exists':
+      return 'ATTRIBUTE_EXISTS';
+    case 'attribute_not_exists':
+      return 'ATTRIBUTE_NOT_EXISTS';
     default:
       return '=';
   }

src/types.ts

@@ -25,7 +25,9 @@ export type DynamoDBOperators =
   | 'BEGINS_WITH'
   | 'IN'
   | 'EXISTS'
-  | 'CONTAINS';
+  | 'CONTAINS'
+  | 'ATTRIBUTE_EXISTS'
+  | 'ATTRIBUTE_NOT_EXISTS';
 
 /**
  * Operators for where clauses
@@ -41,6 +43,8 @@ export type FilterOperators =
   | 'between'
   | 'like'
   | 'exists'
+  | 'attribute_exists'
+  | 'attribute_not_exists'
   | 'beginsWith';
 /**
  * Matching predicate comparison