fix(param-util): more strict regex for mergeUpdateExpressions

Author: mumenthalers

src/dynamo/expression/param-util.spec.ts

@@ -81,5 +81,15 @@ describe('ParamUtils', () => {
         'SET #doRemove = :doRemove, #doAdd = :doAdd REMOVE c, d',
       )
     })
+    it('should work correctly even if a property is named DELETE', () => {
+      expect(
+        mergeUpdateExpressions(
+          'DELETE #myProp, #myProp2, #DELETE ADD #myOtherProp :myOtherVal',
+          'SET #addresses = list_append(#addresses, :addresses), #name = :name',
+        ),
+      ).toBe(
+        'DELETE #myProp, #myProp2, #DELETE ADD #myOtherProp :myOtherVal SET #addresses = list_append(#addresses, :addresses), #name = :name',
+      )
+    })
   })
 })

src/dynamo/expression/param-util.ts

@@ -62,8 +62,11 @@ export function mergeUpdateExpressions(expression1: string, expression2: string)
 }
 
 function splitUpdateExpressionToActionKeyword(updateExpression: string): UpdateExpressionsByKeyword {
-  return updateExpression
-    .split(/\s?(SET|REMOVE|ADD|DELETE)\s/g)
+  // add a whitespace at the beginning of the expression to be able to work with a more stricter regex
+  return ` ${updateExpression}`
+  // the regex ensures a whitespace at the beginning of the ActionWord
+  // -> to not have problems with properties named exactly as an ActionKeyword
+    .split(/\s(SET|REMOVE|ADD|DELETE)\s/g)
     .reduce((u, e, i, arr) => {
       if (isUpdateActionKeyword(e)) {
         u[e] = arr[i + 1]