feat(typing): narrow typing when not defining returnValues

the default returnValues is NONE which means there is no value returned from exec. The actual implementation in write.request.ts return T | void depending on returnValues, but we want the default return value of exec() to be void, so we don't have to cast any time we use the exec() method

Author: michaelwittwer

src/dynamo/request/delete/delete.request.ts

@@ -26,10 +26,20 @@ export class DeleteRequest<T> extends WriteRequest<T, DynamoDB.DeleteItemInput,
     return this
   }
 
+  /*
+   * kind a hacky - this is just for typing reasons so Promise<void> is the default return type when not defining a
+   * returnValues other than NONE
+   *
+   * const valueVoid = new DeleteRequest(...).exec()
+   * const valueMyModel = new DeleteRequest(...).returnValues('ALL_OLD').exec()
+   */
+  exec(): Promise<void> {
+    return <Promise<void>>super.exec()
+  }
+
   execFullResponse(): Promise<DynamoDB.DeleteItemOutput> {
     this.logger.debug('request', this.params)
     return this.dynamoDBWrapper.deleteItem(this.params)
       .then(promiseTap(response => this.logger.debug('response', response)))
   }
 }
-

src/dynamo/request/put/put.request.ts

@@ -38,6 +38,17 @@ export class PutRequest<T> extends WriteRequest<T, DynamoDB.PutItemInput, PutReq
     return this
   }
 
+  /*
+   * kind a hacky - this is just for typing reasons so Promise<void> is the default return type when not defining a
+   * returnValues other than NONE
+   *
+   * const valueVoid = new DeleteRequest(...).exec()
+   * const valueMyModel = new DeleteRequest(...).returnValues('ALL_OLD').exec()
+   */
+  exec(): Promise<void> {
+    return <Promise<void>>super.exec()
+  }
+
   execFullResponse(): Promise<DynamoDB.PutItemOutput> {
     this.logger.debug('request', this.params)
     return this.dynamoDBWrapper.putItem(this.params)

src/dynamo/request/update/update.request.ts

@@ -40,6 +40,17 @@ export class UpdateRequest<T> extends WriteRequest<T, DynamoDB.UpdateItemInput,
     return this
   }
 
+  /*
+   * kind a hacky - this is just for typing reasons so Promise<void> is the default return type when not defining a
+   * returnValues other than NONE
+   *
+   * const valueVoid = new DeleteRequest(...).exec()
+   * const valueMyModel = new DeleteRequest(...).returnValues('ALL_OLD').exec()
+   */
+  exec(): Promise<void> {
+    return <Promise<void>>super.exec()
+  }
+
   execFullResponse(): Promise<DynamoDB.UpdateItemOutput> {
     this.logger.debug('request', this.params)
     return this.dynamoDBWrapper.updateItem(this.params)

src/dynamo/request/write.request.ts

@@ -48,7 +48,7 @@ export abstract class WriteRequest<T,
   /**
    * @returns { void } if no ReturnValues are requested, { T } if the requested ReturnValues are ALL_OLD|ALL_NEW or {Partial<T>} if the requested ReturnValues are UPDATED_OLD|UPDATED_NEW
    */
-  exec(): Promise<T | undefined> {
+  exec(): Promise<T | void> {
     return this.execFullResponse()
       .then(response => {
         if ('Attributes' in response && typeof response.Attributes === 'object' && response.Attributes !== null) {