Wecome to this ASP.NET solution which contains examples of how to incorporate, build and Unit Test React front-end inside an ASP.NET Core (1.0.0) and ASP.NET MVC5 application.

Licence: MIT

The example projects are designed to be scalable up to a real-world, production-ready applications with full build, test, and deployment capabilities.

This new article covers the changes made to the ReactWebPack.Core Kanban application to use the Redux store instead of the Flux store.

This is about improving the Unit Test to test some of the parts of the ReactWebPack.Core application, which requires the mocking of the async KanbanApi module and handling the JavaScript promises that it uses.

This gives some guidance on how to test React components in a React application that uses Redux.

The solution contains three projects:

1. ReactJsNet.MVC5: A simple example of using the ReactJS.Net package to on-the-fly convert React JSX files to currently supported standards, e.g. ES5, JavaScript. (Note: Also available for ASP.NET Core, see this NuGet package).
2. ReactWebPack This is a more complex React application which is built using the WebPack module bundler and Babel Transpiler

• ReactWebPack.Core is an ASP.NET Core (1.0.0) MVC version using Redux store.
• ReactWebPack.MVC5 is a ASP.NET MVC5 version using the Flux store.
  Note: This now contains the Unit Tests.

3. ReactTests: A separate project containing a setup for running Unit Tests on React components and libraries. This was removed because having a separate project causes a problem of having multiple copies of React. Now found as part of ReactWebPack.Core.

NOTE: The ReactWebPack.Core project used to be at Core version RC2, but has been updated to Core 1.0.0. While I changed the namespace I haven't changed the folder names as it would mean updating every link to this project from the acticles I ahve written.

If you clone/copy this GitHub Repository then you need to:

• I assume you are running Visual Studio 2015 (VS2015), which includes a version of Node.js just for VS2015.
  NOTE: You can use Visual Studio 2013 for the MVC5 versions, but you need VS2015 for the ASP.NET Core versions.

• If you want to build the application that uses ASP.NET Core then you need to download and install Visual Studio 2015 Update 3 and .NET Core 1.0.0 - VS 2015 Tooling Preview 2 - See The .NET Core Windows page for the latest links.

• I recommend you use Visual Studio Code (VSCode) to run the build/test React command scripts. You will need to:

  • Install VSCode
  • Install proper Node.js if not already loaded.
    Type node --version to check if nodejs is already installed.
  • Install the the extension VSCode NPM Scripts extension.

• If you want to run the React command scripts from Visual Studio load the NPM Task Runner extension through Tools -> Extensions and Updates -> Online -> search for NPM Task Runner.

You should set the specific project you want to try as the startup application. Simply right-click the project and select Set as Startup Project.

If you want to run any of the MVC versions to see how it works 'out-of-the-box' then press F5 (Start Debugging).

Note: ReactWebPack.Core or ReactWebPack.MVC5 it will run with the last build I did on that project's React code. ReactJsNet.MVC5 transpiles on the fly anyway, so will always be up to date.

Note: In the ReactWebPack.Core project VS2015 shows the message - not installed after the Dependencies folder and the Dependencies\npm folder. It seems this is a known issue: see issue NPM optional package installation failure #479 in aspnet/Tooling.

These sections apply to:

• ReactWebPack.Core
• ReactWebPack.MVC5

NOTE: ReactJsNet.MVC5 doesn't need a build.

If you want to run any of the build/test processes then you need to ensure the NPM packages are loaded in that specific project. To do that load the solution into Visual Studio and right-click the packages.json file in the project you are interested in. Then click Restore Packages at the top of the context menu.

Note: If you restore all the packages and compile all the projects the solution takes up a LOT of disk space.

VSCode is a great way to handle the React code because it understands JSX and ES6 syntax. Its also very lightweight, i.e. it has a small memory footprint and is fast. Because the AspNetReactSamples solution has multiple package.json files I have added some user setting to help the VSCode npm Scripts extension work with all of the projects. The process is:

1. Make sure you have VSCode setup properly - see 1. How to setup.
2. Open the outer directory of the samples, e.g. AspNetReactSamples, with VSCodes Open Folder command.
3. Type F1 key, then npm and select npm: Run Script (shortcut: cntrl-R shift-R)
4. You are then presented with scripts for the project ReactWebPack.Core. Pick the one you want to run e.g. dev-build.
   *NOTE: commands with watch in them stay running and will rebuild the files and re-run the command if a .js file is saved. Very useful when debugging/developing.
5. The output of the process is shown in a new console window, including any errors.
   NOTE: To stop a watch task type cntrl-C in the console window.

If you don't want to learn VSCode then you can run the React build/test commands from Visual Studio:

1. Make sure you have Visual Studio setup properly, especially that you have installed the NPM Task Runner extension - see 1. How to setup.
2. Open the Task Runner Explorer window (found via Views->Other Windows->Task Runner Explorer) select the package.json of the project you want to run commands for in the top dropdown and then click the command you want to run. See example screenshot below:
   
   The results will appear in the Task Runner Explorer output pane.

*NOTES:

• commands with watch in them stay running and will rebuild the files and re-run the command if a *.js file is saved. Very useful when debugging/developing.
• I have sometimes found that Task Runner NOT show the ReactWebPack.Core NPM commands commands. I found out the NPM Task Runner tool was disabled (not sure why). If you can't see the build commands then check that it is enabled via Tools->Extensions and Updates->Installed and search for NPM.*

I have now written quite a few Unit Tests and the way I set this up has changed. It used to be in a separate project, but that caused a problem of multiple copies of React. The Unit Tests are therefore now part of ReactWebPack.Core.

The key files for Unit Testing are:

1. karam.config.js which holds all the info for the Karam test runner.
2. tests.webpack.js which finds the unit tests to run.
3. package.json which holds all the libraries needed for Unit Testing, and the scripts to run the unit tests.
4. The Unit Tests can be found in the directory JsUnitTests/Tests.

See the article Templates for building React front-ends in ASP.NET Core and MVC5 for more information on Unit Testing and the newer articles:

• Adding mocking to React.js Unit Tests about mocking modules to improve testing.
• Unit Testing React components that use Redux which talks testing React apps that use Redux.

If you want to create your own ASP.NET application that runs a React.js application then it is fairly easy to copy a few files from these sample projects to add React.js build and run capabilites.

The two projects, ReactWebPack.Core or ReactWebPack.MVC5, contain four key files. You should pick the files for the specific

1. package.json: npm library files and scripts The package.json file holds all the libraries that you need to a) build and b) run the React.js application. You need to decide what libraraies you want for your application, but the sample has a good starting point. The ASP.NET Core package.json and ASP.NET MVC5 package.json are different, but only because they have different libraries.

• The ASP.NET Core package.jsoncontains the various React.js Redux libraries and the normal Gulp build automation tools that ASP.NET Core uses to productionise the JavaScript and CSS files.
• The ASP.NET MVC5 package.json contains the React.js Flux store instead of Redux, as this implements the older style of the Kanban application. By default MVC5 applciations do not included any Gulp or Grunt build automation tools in this.

2. webpack.config.js: the file that controls the build of the React.js application This file controls how the React.js is transpiled and linked to form the two JavaScript files that contain the built React.js application. The ASP.NET Core version and the ASP.NET MVC5 version are very similar, which a few key differences which I will spell out below:
   The ASP.NET Core *webpack.config.js contains the follow lines especially for ASP.NET Core:

• line 22: it refers to wwwroot\js directory, as that is where published files need to go.
• line 24: if in production mode the files are minified so we make the ending ....min.js. That stops Gulp from doing any more concatenating/minification on the files.
  The ASP.NET MVC5 *webpack.config.js contains the follow lines especially for ASP.NET MVC:
• line 22: it puts the published files in the /js directory.
• I don't add ...min.js to the end of production produced files. It made it easier for testing, but you might want to do that.
  BOTH files look for the top level React.js file in the file /app/App.js (see line 18 in both files). If you want to move/change the name of your top level React.js file then you need to adit this.

3. The razor Index.cshtml and Layout .cshtml files To get the React.js application shown then you need to put it in MVC Views file, with an appropriate layout file to load any associated libraries. The way you do this has changed between the ASP.NET MVC5 release and the newer ASP.NET Core release.

• For the ASP.NET Core version look at Home/Index.cshmtl and the Shared/_ReactLayout.cshtml files.
• For the ASP.NER MVC5 version look at Home/Index.cshmtl and the Shared/_ReactLayout.cshtml files.

4. Unit Tests If you want to create Unit tests (of course you do!) then you need to add the unit test configuration files, the npm test libraries & scripts and write the Unit Tests themselves. Have a look at the section 4c. Notes about the Unit Tests for more on this.

While the React build process have totally valid development and production paths I haven't handled all the ASP.NET side of production/deployment. Things that would need to be added:

• I have set up cachebuster values to ReactWebPack.Core in production mode but I haven't done anything in the ReactWebPack.MVC5 project.
• I have changed the endings of the vendor.js and main.js to ...min.js in ReactWebPack.Core, but not in ReactWebPack.MVC5.
• The ASP.NET Core project now uses the VS2015 bundle and minifier extension instead of Gulp. I have minified the CSS files using this extension so there should be no need to run it again.