### Fixed

- [Issue #464](#464); When specifing return attributes on retrieval methods, ElectroDB would unexpectly return null or missing values if the options chosen resulted in an empty object being returned. This behavor could be confused with no results being found. ElectroDB now returns the empty object in these cases.

### Added
- ElectroDB Error objects no contain a `params()` method. If your operation resulted in an error thrown by the DynamoDB client, you can call the `params()` method to get the compiled parameters sent to DynamoDB. This can be helpful for debugging. Note, that if the error was thrown prior to parameter creation (validation errors, invalid query errors, etc) then the `params()` method will return the value `null`.

CHANGELOG.md

@@ -550,4 +550,11 @@ All notable changes to this project will be documented in this file. Breaking ch
 
 ## [3.0.1]
 ### Fixed
-- The execution option `{ compare: "attributes" }` used incorrect expression comparisons that impacted `lte` queries on indexes with a single composite key.   
+- The execution option `{ compare: "attributes" }` used incorrect expression comparisons that impacted `lte` queries on indexes with a single composite key.   
+
+## [3.1.0]
+### Fixed
+- [Issue #464](https://github.com/tywalch/electrodb/issues/464); When specifing return attributes on retrieval methods, ElectroDB would unexpectly return null or missing values if the options chosen resulted in an empty object being returned. This behavor could be confused with no results being found. ElectroDB now returns the empty object in these cases.
+
+### Added
+- ElectroDB Error objects no contain a `params()` method. If your operation resulted in an error thrown by the DynamoDB client, you can call the `params()` method to get the compiled parameters sent to DynamoDB. This can be helpful for debugging. Note, that if the error was thrown prior to parameter creation (validation errors, invalid query errors, etc) then the `params()` method will return the value `null`. 

RELEASE.md

@@ -31,4 +31,4 @@ The approach for "Watch All" syntax for attributes (e.g. `{watch: "*"}`) weighed
 
 ### ExpressionAttributeValues Properties
 
-To prevent clashes between `update` values and filter conditions, a change was made to how the property names of `ExpressionAttributeValues` are constructed. This is not a breaking change but if you have tests to specifically compare param results against static JSON you will need to update that JSON. Changes to JSON query parameters is not considered a breaking major version change.
+To prevent clashes between `update` values and filter conditions, a change was made to how the property names of `ExpressionAttributeValues` are constructed. This is not a breaking change but if you have tests to specifically compare param results against static JSON you will need to update that JSON. Changes to JSON query parameters is not considered a breaking major version change.

index.d.ts

@@ -2935,9 +2935,10 @@ export class ElectroError<E extends Error = Error> extends Error {
   readonly name: "ElectroError";
   readonly code: number;
   readonly date: number;
-  readonly isElectroError: boolean;
   readonly cause: E | undefined;
-  ref: {
+  readonly isElectroError: boolean;
+  readonly params: () => Record<string, unknown> | null;
+  readonly ref: {
     readonly code: number;
     readonly section: string;
     readonly name: string;

package.json

@@ -1,6 +1,6 @@
 {
   "name": "electrodb",
-  "version": "3.0.1",
+  "version": "3.1.0",
   "description": "A library to more easily create and interact with multiple entities and heretical relationships in dynamodb",
   "main": "index.js",
   "scripts": {

src/entity.js

@@ -466,15 +466,18 @@ class Entity {
         if (err.__isAWSError) {
           stackTrace.message = `Error thrown by DynamoDB client: "${err.message}" - For more detail on this error reference: https://electrodb.dev/en/reference/errors/#aws-error`;
           stackTrace.cause = err;
+          e.applyParamsFn(stackTrace, err.__edb_params);
           return Promise.reject(stackTrace);
         } else if (err.isElectroError) {
+          e.applyParamsFn(err, err.__edb_params);
           return Promise.reject(err);
         } else {
           stackTrace.message = new e.ElectroError(
             e.ErrorCodes.UnknownError,
             err.message,
             err,
           ).message;
+          e.applyParamsFn(stackTrace, err.__edb_params);
           return Promise.reject(stackTrace);
         }
       }
@@ -516,6 +519,10 @@ class Entity {
       .catch((err) => {
         notifyQuery();
         notifyResults(err, false);
+        Object.defineProperty(err, '__edb_params', {
+          enumerable: false,
+          value: params,
+        })
         err.__isAWSError = true;
         throw err;
       });
@@ -935,7 +942,7 @@ class Entity {
               response.Item,
               config,
             );
-            if (Object.keys(results).length === 0) {
+            if (Object.keys(results).length === 0 && !config._objectOnEmpty) {
               results = null;
             }
           } else if (!config._objectOnEmpty) {
@@ -957,7 +964,7 @@ class Entity {
                 item,
                 config,
               );
-              if (Object.keys(record).length > 0) {
+              if (Object.keys(record).length > 0 || config._objectOnEmpty) {
                 results.push(record);
               }
             }
@@ -967,7 +974,7 @@ class Entity {
             response.Attributes,
             config,
           );
-          if (Object.keys(results).length === 0) {
+          if (Object.keys(results).length === 0 && !config._objectOnEmpty) {
             results = null;
           }
         } else if (config._objectOnEmpty) {
@@ -1646,6 +1653,7 @@ class Entity {
       order: undefined,
       hydrate: false,
       hydrator: (_entity, _indexName, items) => items,
+      _objectOnEmpty: false,
       _includeOnResponseItem: {},
     };
 
@@ -1727,6 +1735,9 @@ class Entity {
 
       if (Array.isArray(option.attributes)) {
         config.attributes = config.attributes.concat(option.attributes);
+        if (config.attributes.length > 0) {
+          config._objectOnEmpty = true;
+        }
       }
 
       if (option.preserveBatchOrder === true) {

src/errors.js

@@ -280,7 +280,7 @@ function makeMessage(message, section) {
 }
 
 class ElectroError extends Error {
-  constructor(code, message, cause) {
+  constructor(code, message, cause, params = null) {
     super(message, { cause });
     let detail = ErrorCodes.UnknownError;
     if (code && code.sym === ErrorCode) {
@@ -298,9 +298,21 @@ class ElectroError extends Error {
     this.code = detail.code;
     this.date = Date.now();
     this.isElectroError = true;
+    applyParamsFn(this, params);
   }
 }
 
+function applyParamsFn(error, params = null) {
+  Object.defineProperty(error, 'params', {
+    enumerable: false,
+    writable: true,
+    configurable: true,
+    value: () => {
+      return params;
+    }
+  });
+}
+
 class ElectroValidationError extends ElectroError {
   constructor(errors = []) {
     const fields = [];
@@ -389,6 +401,7 @@ class ElectroAttributeValidationError extends ElectroError {
 module.exports = {
   ErrorCodes,
   ElectroError,
+  applyParamsFn,
   ElectroValidationError,
   ElectroUserValidationError,
   ElectroAttributeValidationError,

test/ts_connected.client.spec.ts

@@ -190,6 +190,202 @@ describe("dynamodb sdk client compatibility", () => {
         expect(results).to.be.an("array");
       });
 
+      describe('electro error params', () => {
+        it('the params function should not be visible in console logs', async () => {
+          const entity = new Entity(
+            {
+              model: {
+                service: "tests",
+                entity: uuid(),
+                version: "1",
+              },
+              attributes: {
+                prop1: {
+                  type: "string",
+                  default: () => uuid(),
+                  field: "p",
+                },
+                prop2: {
+                  type: "string",
+                  required: true,
+                  field: "r",
+                },
+                prop3: {
+                  type: "string",
+                  required: true,
+                  field: "a",
+                },
+              },
+              indexes: {
+                farm: {
+                  pk: {
+                    field: "pk",
+                    composite: ["prop1"],
+                  },
+                  sk: {
+                    field: "sk",
+                    composite: ["prop2"],
+                  },
+                },
+              },
+            },
+            {client, table: "electro"},
+          );
+
+          const prop1 = uuid();
+          const prop2 = uuid();
+          const prop3 = "abc";
+
+          let params: Record<string, unknown> | undefined = undefined;
+          await entity.create({prop1, prop2, prop3}).go();
+          const results = await entity.create({prop1, prop2, prop3}).go()
+            .then(() => null)
+            .catch((err: ElectroError) => err);
+
+          expect(results).to.not.be.null;
+
+          if (results) {
+            expect(JSON.parse(JSON.stringify(results))).to.not.have.keys('params');
+            expect(Object.keys(results).find(key => key === 'params')).to.be.undefined;
+            console.log(results);
+          }  
+        });
+
+        it('should return null parameters if error occurs prior to compiling parameters', async () => {
+          const entity = new Entity(
+            {
+              model: {
+                service: "tests",
+                entity: uuid(),
+                version: "1",
+              },
+              attributes: {
+                prop1: {
+                  type: "string",
+                  default: () => uuid(),
+                  field: "p",
+                },
+                prop2: {
+                  type: "string",
+                  required: true,
+                  field: "r",
+                },
+                prop3: {
+                  type: "string",
+                  required: true,
+                  field: "a",
+                  validate: (val) => {
+                    return val !== "abc";
+                  }
+                },
+              },
+              indexes: {
+                farm: {
+                  pk: {
+                    field: "pk",
+                    composite: ["prop1"],
+                  },
+                  sk: {
+                    field: "sk",
+                    composite: ["prop2"],
+                  },
+                },
+              },
+            },
+            {client, table: "electro"},
+          );
+
+          const prop1 = uuid();
+          const prop2 = uuid();
+          const prop3 = "abc";
+
+          let params: Record<string, unknown> | undefined = undefined;
+
+
+          const results = await entity.create({prop1, prop2, prop3}).go({
+              logger: (event) => {
+                if (event.type === 'query') {
+                  params = event.params;
+                }
+              }
+            })
+            .then(() => null)
+            .catch((err: ElectroError) => err);
+
+          expect(params).to.be.undefined;  
+          expect(results).to.not.be.null;
+
+          if (results) {
+            expect(results.params()).to.be.null;
+          } 
+        });
+
+        it('should return the parameters sent to DynamoDB if available', async () => {
+          const entity = new Entity(
+            {
+              model: {
+                service: "tests",
+                entity: uuid(),
+                version: "1",
+              },
+              attributes: {
+                prop1: {
+                  type: "string",
+                  default: () => uuid(),
+                  field: "p",
+                },
+                prop2: {
+                  type: "string",
+                  required: true,
+                  field: "r",
+                },
+                prop3: {
+                  type: "string",
+                  required: true,
+                  field: "a",
+                },
+              },
+              indexes: {
+                farm: {
+                  pk: {
+                    field: "pk",
+                    composite: ["prop1"],
+                  },
+                  sk: {
+                    field: "sk",
+                    composite: ["prop2"],
+                  },
+                },
+              },
+            },
+            {client, table: "electro"},
+          );
+
+          const prop1 = uuid();
+          const prop2 = uuid();
+          const prop3 = "abc";
+
+          let params: Record<string, unknown> | undefined = undefined;
+          await entity.create({prop1, prop2, prop3}).go();
+          const results = await entity.create({prop1, prop2, prop3}).go({
+            logger: (event) => {
+              if (event.type === 'query') {
+                params = event.params;
+              }
+            }
+          })
+            .then(() => null)
+            .catch((err: ElectroError) => err);
+
+          expect(results).to.not.be.null;
+
+          if (results) {
+            expect(results.params()).to.not.be.undefined.and.not.to.be.null;
+            expect(results.params()).to.deep.equal(params);
+          }
+        });
+      });
+
       it('should include original aws error as cause on thrown ElectroError', async () => {
         const entity = new Entity(
             {