Software Developer Ben

This post details the setup process for a NoSQL database with MongoDB. Firstly, go to the MongoDB website  and navigate to the Download Center. Download the correct version and run the installer. For ease of access, customise the location to be on the C drive root. In the command line, go to the bin within the mongodb folder. Return the below in order to set up the directory and logging. After hitting enter, the following will be displayed. The MongoDB service is now started and we can go ahead and view and customise some no-SQL databases. Returning "show dbs" in the command line will display the current databases. We can see we have a local and admin database. To create a new database, for example "mycustomers" we have to return "use mycustomers". If the "mycustomers" database already existed, then the "use mycustomers" command would not create a new database, but instead make "mycustomers" the active database. ...

This post examines how a user password can be securely stored. There are many blog posts elsewhere online that detail the importance behind securing passwords securely; this post will simply focus on the code which can accomplish the task. The extracts below are from a simple console application that demonstrates the method used to securely save and verify a user password. In the Main  method, firstly the user is prompted to enter their password which is immediately passed into the HashNewPassword  method which itself salts and hashes the password and assigns it to the variable hashedPassword . In the HashNewPassword  method, the salt  variable is declared as an array of bytes. Using the RNGCryptoServiceProvider from  System.Security.Cryptography , a good standard salt is created. The salt, with the entered password, is then passed into the HashPassword  method. In the HashPassword  method, the hash  variable is declared...

This post is the second in the series of posts regarding implementing Mspec for unit tests within TDD. This section looks at how tests can be written to check that the correct exceptions are thrown under certain conditions. An understanding of  Test-driven development (TDD) with Mspec - Part 1 is assumed. The test shown  here will cover the throwing of a validation exception when a user is added without a name. New users are added using an AddUserModel , which is shown below. Note that the Required  tag is appended to both the Name  and Age  properties. In the post method in the user controller, first the model state is checked to ensure it is valid. If the model is not valid (i.e if there is no value for either the age or name, or both) a validation exception is thrown. In the test an AddUserModel  is created with a null name in the Establish  step. Then, in the Because  step the result is set to the output of the post method. Howe...

This post describes how to use MSpec tests to implement test-driven development (TDD). Details on TDD can be found on  this  wikipedia page. Machine.specifications is simple to install through the Nuget package manager, more information can be found on the  MSpec site . Here Machine Fakes is also used to create the unit tests, more information on this can be found here . This blog post will be analogous to Behaviour-driven development (BDD) with SpecFlow - Part 1 , hence a direct comparison is able to be made between the two testing methodologies. The example below will show the Mspec test for the command query that gets all users from the database. By convention Mspec classes are titled in snake case. The Subject attribute is added, although this is not essential it is good practice to do so. The test class inherits from WithSubject (from Machine.Fakes) with the type being the class where the testable code resides. Note : the following code snippets are all cont...

In a recent project, I was tasked with implementing functionality into an application to allow admin users the ability to add/edit descriptions of sections of work. These sections form part of a workbook that the regular users must complete. The admin users may want to add bullet points, hyperlinks as well as bold or italic text to the aforementioned descriptions - so a simple out of the box text input would not suffice. After some research, I opted to use Quill  due to its apparently simplicity and high level of customisation. This blog post will detail the basic setup and usage of Quill, in an Aurelia web project which uses typescript. The above shows a typescript file for description rows. On this file there is a method that opens an edit modal for a description, it is this modal that uses a quill editor so that the user can edit the description. In the activate method the Quill options are set using a method located in a helper file (see below). In the openEditDescript...

As detailed on the  Dapper Tutorial Site , Dapper is an object relational mapper (ORM), which means it handles the mapping between the code base and the data store. The setup is simple and explained effectively on the tutorial site. Hence, this post shall not describe the setup steps for Dapper, but instead show an example of how it can be used, in the context of a data import. This example deals with the real world scenario of an application with a table of employees. The employee information that populates this table derives from a different database on the server, that is used by other applications within the hypothetical company. The importer must first get the data from the common database, then make any required calculations before finally passing data into the application database table. In addition, it must handle updates to users that have already been imported previously. I will be using the Northwind  database in this example, specifically the employees table. T...

This post is the second in the series of posts regarding implementing SpecFlow for unit tests within BDD. This section looks at how tests can be written to check that the correct exceptions are thrown under certain conditions. An understanding of  Behaviour-driven development (BDD) with Specflow - Part 1 and Using the Mediatr pipeline with Fluent Validation  is assumed. Firstly, two steps must be written. A step to add the user without a name and a second to return the error message. Step to add invalid user The user data is passed in as a dynamic, then the properties are assigned to an AddUserModel , which is what is passed to the AddUserRequest . The AddUser  method on the administration engine is called and the exception remembered in the test context. Note that this exact step could also be used in a test to check that a user can not be added without an age assigned. Step to verify exception The exception is recalled from the text context and verified...

This post describes how to utilise SpecFlow to write unit tests that implement behaviour-driven development (BDD). Details on the BDD can be found on this wikipedia page. SpecFlow is simple to install through the Nuget package manager, more information can be found on the SpecFlow site . SpecFlow tests comprise of two main elements: features and steps. In feature files, scenarios are written which together test all the behaviours of the feature. Each test will call methods in a step file, which is where the C# code resides and the actual. In this blog post, we just look at a couple of very simple examples. In the future, there will be posts which go into more detail about the power of SpecFlow. Below is an example feature file for getting all users from a database, titled Get all users . At the top, the feature is defined subsequently a bit more detail is given. This is a suite of tests that will prescribe the behaviour for getting all users. The first scenario details the...

This post details the setup process for Entity Framework code first migrations. Assume a new project with a  User  entity, with just 2 properties: Id and Name. The database schema is yet to be created. Creating the Schema Install the Entity Framework package, through the Nuget package manager or other means - more information on the package can be found on the project site Add a UserConfiguration  file to control the mapping between entity and schema Add IDataContext  and DataContext files, here every persisted entity must be declared as a DbSet and the corresponding configuration file must be added to the model builder as shown Add a connection string in the web config file, to an existing database In the package manager console, select the project where the Entity Framework package has been installed. Type update-database  and run. This will create the schema in the database given in the connection string Updating the Schema Now, make a ...

Fluent Migrator makes the process of writing database migrations much easier and less error prone by removing the need to write sql scripts. Instead, all schema changes are written in C# files, utilising methods in the Fluent Migrator library. This post describes the required steps to setup Fluent Migrator, in the context of creating a user table. Install the Fluent Migrator package into the migrations project - more information on installation can be found on the project site In an appropriate location, add a new C# file to become the first migration The file should implement Migration, from the Fluent Migrator package Decorate the class with the Migration attribute, and as this is the first migration in the project it takes the argument 1 Every migration class requires an Up and a Down method, to commit the schema changes and rollback if an error occurs in the process In the Up  method, a  User  table is scripted for, with an Id field (a primary key) an...

This post details the process to create a domain auditing system using NHibernate events. Upon any change to a mapped entity, details of the change are posted to an audit table in the database. Setup Create the AuditEventListener , which inherits from IPostInsertEventListener , IPostUpdateEventListener and IPostDeleteEventListener;  this will enable the logging of inserts, updates and deletes respectively A custom time provider is used here, to append the current date and time to the logging, though using the native DateTime.Now is normally sufficient Add the  OnPostUpdate   method and pass in a  PostUpdateEvent Using the entity  property on the PostUpdateEvent , check to ensure the entity is not an AuditLogEntry , as it makes no sense to audit the audit entity Verify that the old state of the entity is not null. If the old state is null, it is clear that this is not an update, and so make the method throw an error if this is the case U...