Fix missing ProjectionExpression on scan with attributes (#511)

* fix: missing ProjectionExpression on scan with attributes

* add tests

* add changelog

* 3.4.5

Author: anatolzak

CHANGELOG.md

@@ -590,4 +590,8 @@ All notable changes to this project will be documented in this file. Breaking ch
 - [Issue #439](https://github.com/tywalch/electrodb/issues/439); Fixed missing TypeScript types for `attributes` property on `scan`, `find`, and `match` methods.
 
 ## [3.4.4]
-- Reduced ElectroDB's pre/post-processing overhead before/after DynamoDB requests by as much as 85% in some cases.
+- Reduced ElectroDB's pre/post-processing overhead before/after DynamoDB requests by as much as 85% in some cases.
+
+## [3.4.5]
+### Fixed
+- [Issue #510](https://github.com/tywalch/electrodb/issues/510); Fixes the issue where ElectroDB did not create the ProjectionExpression DynamoDB parameter when scanning a table and specifying attributes to return.

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "electrodb",
-  "version": "3.4.4",
+  "version": "3.4.5",
   "description": "A library to more easily create and interact with multiple entities and heretical relationships in dynamodb",
   "main": "index.js",
   "scripts": {

package.json

@@ -2012,7 +2012,10 @@ class Entity {
         );
         break;
       case MethodTypes.scan:
-        params = this._makeScanParam(filter[ExpressionTypes.FilterExpression]);
+        params = this._makeScanParam(
+          filter[ExpressionTypes.FilterExpression],
+          config,
+        );
         break;
       /* istanbul ignore next */
       default:
@@ -2228,7 +2231,7 @@ class Entity {
   }
 
   /* istanbul ignore next */
-  _makeScanParam(filter = {}) {
+  _makeScanParam(filter = {}, options = {}) {
     let indexBase = TableIndex;
     let hasSortKey = this.model.lookup.indexHasSortKeys[indexBase];
     let accessPattern =
@@ -2291,7 +2294,10 @@ class Entity {
       params.FilterExpression = filterExpressions.join(" AND ");
     }
 
-    return params;
+    return this._applyProjectionExpressions({
+      parameters: params,
+      config: options,
+    });
   }
 
   _makeSimpleIndexParams(partition, sort) {

src/entity.js

@@ -4380,6 +4380,16 @@ describe("attributes query option", () => {
       },
     ]);
 
+
+    const scanParams = entityWithSK.scan.params({
+      // @ts-ignore - the ParamOptions type does not accept attributes
+      // but this is valid in runtime
+      attributes: ["attr2", "attr9", "attr5", "attr10"],
+    });
+    expect(scanParams.ProjectionExpression).to.equal(
+      "#__edb_e__, #__edb_v__, #pk, #sk, #attr2, #prop9, #attr5, #attr10",
+    );
+
     const matchItem = await entityWithSK
       .match({
         attr1: item.attr1,