Table of Contents for
Node.js 8 the Right Way

Version ebook / Retour

Cover image for bash Cookbook, 2nd Edition Node.js 8 the Right Way by Jim Wilson Published by Pragmatic Bookshelf, 2018
  1. Title Page
  2. Node.js 8 the Right Way
  3. Node.js 8 the Right Way
  4. Node.js 8 the Right Way
  5. Node.js 8 the Right Way
  6.  Acknowledgments
  7.  Preface
  8. Why Node.js the Right Way?
  9. What’s in This Book
  10. What This Book Is Not
  11. Code Examples and Conventions
  12. Online Resources
  13. Part I. Getting Up to Speed on Node.js 8
  14. 1. Getting Started
  15. Thinking Beyond the web
  16. Node.js’s Niche
  17. How Node.js Applications Work
  18. Aspects of Node.js Development
  19. Installing Node.js
  20. 2. Wrangling the File System
  21. Programming for the Node.js Event Loop
  22. Spawning a Child Process
  23. Capturing Data from an EventEmitter
  24. Reading and Writing Files Asynchronously
  25. The Two Phases of a Node.js Program
  26. Wrapping Up
  27. 3. Networking with Sockets
  28. Listening for Socket Connections
  29. Implementing a Messaging Protocol
  30. Creating Socket Client Connections
  31. Testing Network Application Functionality
  32. Extending Core Classes in Custom Modules
  33. Developing Unit Tests with Mocha
  34. Wrapping Up
  35. 4. Connecting Robust Microservices
  36. Installing ØMQ
  37. Publishing and Subscribing to Messages
  38. Responding to Requests
  39. Routing and Dealing Messages
  40. Clustering Node.js Processes
  41. Pushing and Pulling Messages
  42. Wrapping Up
  43. Node.js 8 the Right Way
  44. Part II. Working with Data
  45. 5. Transforming Data and Testing Continuously
  46. Procuring External Data
  47. Behavior-Driven Development with Mocha and Chai
  48. Extracting Data from XML with Cheerio
  49. Processing Data Files Sequentially
  50. Debugging Tests with Chrome DevTools
  51. Wrapping Up
  52. 6. Commanding Databases
  53. Introducing Elasticsearch
  54. Creating a Command-Line Program in Node.js with Commander
  55. Using request to Fetch JSON over HTTP
  56. Shaping JSON with jq
  57. Inserting Elasticsearch Documents in Bulk
  58. Implementing an Elasticsearch Query Command
  59. Wrapping Up
  60. Node.js 8 the Right Way
  61. Part III. Creating an Application from the Ground Up
  62. 7. Developing RESTful Web Services
  63. Advantages of Express
  64. Serving APIs with Express
  65. Writing Modular Express Services
  66. Keeping Services Running with nodemon
  67. Adding Search APIs
  68. Simplifying Code Flows with Promises
  69. Manipulating Documents RESTfully
  70. Emulating Synchronous Style with async and await
  71. Providing an Async Handler Function to Express
  72. Wrapping Up
  73. 8. Creating a Beautiful User Experience
  74. Getting Started with webpack
  75. Generating Your First webpack Bundle
  76. Sprucing Up Your UI with Bootstrap
  77. Bringing in Bootstrap JavaScript and jQuery
  78. Transpiling with TypeScript
  79. Templating HTML with Handlebars
  80. Implementing hashChange Navigation
  81. Listing Objects in a View
  82. Saving Data with a Form
  83. Wrapping Up
  84. 9. Fortifying Your Application
  85. Setting Up the Initial Project
  86. Managing User Sessions in Express
  87. Adding Authentication UI Elements
  88. Setting Up Passport
  89. Authenticating with Facebook, Twitter, and Google
  90. Composing an Express Router
  91. Bringing in the Book Bundle UI
  92. Serving in Production
  93. Wrapping Up
  94. Node.js 8 the Right Way
  95. 10. BONUS: Developing Flows with Node-RED
  96. Setting Up Node-RED
  97. Securing Node-RED
  98. Developing a Node-RED Flow
  99. Creating HTTP APIs with Node-RED
  100. Handling Errors in Node-RED Flows
  101. Wrapping Up
  102. A1. Setting Up Angular
  103. A2. Setting Up React
  104. Node.js 8 the Right Way

Wrapping Up

This chapter explored how to write socket-based networked applications in Node. We developed both ends of a server/client interaction and created a JSON-based protocol for them to communicate.

When our assumptions about the protocol began to fail us, we developed a test case to expose the problem. You wrote a custom Node.js module that extended EventEmitter, a core Node.js class. You also learned one technique for buffering streamed data and incrementally scanning it for messages.

Using npm, you installed Mocha, a popular test framework, and used it to develop a unit test.

Writing simple networked applications in Node.js, like those in this chapter, doesn’t take very much code. After only a few lines, you have a functioning server or client application.

However, writing robust applications is harder when you consider the many ways in which a networked application might fail. In the next chapter, we’ll use high-performance messaging libraries and infrastructure to take our Node.js applications to the next level.

The following tasks ask you to improve the code from this chapter, making it more testable and more robust.

Testability

In this chapter, we developed a unit test to run with Mocha. Currently it only tests one behavior of the LDJClient class, namely that it emits a message event for a message that came in as a single data event.

The following questions ask you to think about and implement additional tests.

  • Add a unit test for a single message that is split over two (or more) data events from the stream.

  • Add a unit test that passes in null to the LDJClient constructor and asserts that an error is thrown. Then make the test pass by modifying the constructor.

Robustness

The LDJClient developed in this chapter is somewhat fragile. The questions in this section ask you to expand on its implementation in key ways.

  • The LDJClient already handles the case in which a properly formatted JSON string is split over multiple lines. What happens if the incoming data is not a properly formatted JSON string?

  • Write a test case that sends a data event that is not JSON. What do you think should happen in this case?

  • What happens if the last data event completes a JSON message, but without the trailing newline?

  • Write a case where the stream object sends a data event containing JSON but no newline, followed by a close event. A real Stream instance will emit a close event when going offline—update LDJClient to listen for close and process the remainder of the buffer.

  • Should LDJClient emit a close event for its listeners? Under what circumstances?

Footnotes

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