PragProg Customers

Practical Microservices: Missing expected version in recordViewing function (page 37)

nicholasjhenry

nicholasjhenry

Practical Microservices: Missing expected version in recordViewing function (page 37)

The function call for the message store is:

// video-tutorials/src/app/record-viewings/index.js
messageStore.write(streamName, viewedEvent)

but the function def is:

// video-tutorials/src/message-store/write.js
return (streamName, message, expectedVersion) => {
 // implementation
}

Is there something I missing?

1 comment
#errata/book-practical-microservices
3 832 1

Marked As Solved

nicholasjhenry

nicholasjhenry

Perhaps a lack in my knowledge of JavaScript and Message DB. Calling the function with the first two parameters will result in expectedVersion to be null. If write_message is invoked with a null then no version check is made. I can see how this behaviour would be desired for logging events compared to managing the state of an aggregate (DDD) where the expected version is important.

2
Post #2

Where Next?

View thread on forum
View Practical Microservices's book portal
Post errata for this book
Post a suggestion for this book
Post a question about this book
Post a review about this book
Home PragProg Customers
#errata/book-practical-microservices
3 832 1
Last post

Popular Pragmatic Bookshelf topics Top

abtin
PragProg Customers

Distributed Services With Go - gogoproto on linux
page 20: … protoc command… I had to additionally run the following go get commands in order to be able to compile protobuf code using go...
#errata/book-distributed-services-with-go
14 2953 7
New
jimschubert
PragProg Customers

Distributed Services With Go - Ch 3 index errors on Config
In Chapter 3, the source for index introduces Config on page 31, followed by more code including tests; Config isn’t introduced until pag...
#pragprog#errata/book-distributed-services-with-go
8 1316 3
New
brianokken
PragProg Customers

Python Testing with pytest: pytest now requires markers to be declared (downloadable code)
Many tasks_proj/tests directories exist in chapters 2, 3, 5 that have tests that use the custom markers smoke and get, which are not decl...
#errata/book-python-testing-with-pytest
2 1383 2
New
mikecargal
PragProg Customers

Hands-on Rust: can_place logic is "inside out"
Title: Hands-On Rust (Chapter 11: prefab) Just played a couple of amulet-less games. With a bit of debugging, I believe that your can_p...
#errata/book-hands-on-rust
22 1628 20
New
leonW
PragProg Customers

Python Testing with pytest, Second Edition: File not Found Error (page 43)
I ran this command after installing the sample application: $ cards add do something --owner Brian And got a file not found error: Fil...
#errata/book-python-testing-with-pytest-second-edition
5 4391 7
New
Charles
PragProg Customers

Programming Phoenix LiveView: book not updated to version 1.6 (p. 18)
In general, the book isn’t yet updated for Phoenix version 1.6. On page 18 of the book, the authors indicate that an auto generated of ro...
#errata/book-programming-phoenix-liveview
9 2051 12
New
taguniversalmachine
PragProg Customers

Real-Time Phoenix: ProductChannelTest - undefined function describe/2 (pg 203)
Hi, I am getting an error I cannot figure out on my test. I have what I think is the exact code from the book, other than I changed “us...
#question/book-real-time-phoenix
0 1775 6
New
kolossal
PragProg Customers

Hands on Rust: Need help with error - thread 'main' panicked at 'Failed to load texture
Hi, I need some help, I’m new to rust and was learning through your book. but I got stuck at the last stage of distribution. Whenever I t...
#question/book-hands-on-rust
3 1989 5
New
redconfetti
PragProg Customers

Docker for Rails Developers - 'docker-machine' command deprecated (page 156)
Docker-Machine became part of the Docker Toolbox, which was deprecated in 2020, long after Docker Desktop supported Docker Engine nativel...
/book-docker-for-rails-developers#suggestion
0 896 0
New
roadbike
PragProg Customers

Programming Machine Learning: Setting up your system (p 13)
From page 13: On Python 3.7, you can install the libraries with pip by running these commands inside a Python venv using Visual Studio ...
#question/book-programming-machine-learning
1 989 3
New

Other popular topics Top

PragmaticBookshelf
General Dev>Learning Resources

A Common-Sense Guide to Data Structures and Algorithms, Second Edition
Algorithms and data structures are much more than abstract concepts. Mastering them enables you to write code that runs faster and more e...
pragprog.com
#pragprog/python/ruby#published-book/book-a-common-sense-guide-to-data-structures-and-algorithms-second-edition#math#algorithms/js
19 6022 5
New
ohm
Science/Tech>Tech Chat

Games! Which do you play?
Which, if any, games do you play? On what platform? I just bought (and completed) Minecraft Dungeons for my Nintendo Switch. Other than ...
#games
246 6097 101
New
Exadra37
Linux>Questions

AMD or Intel for Programming with Linux as the OS?
I am thinking in building or buy a desktop computer for programing, both professionally and on my free time, and my choice of OS is Linux...
#mobile#android#web-development#linux#desktop-computer#mobile-development
36 6006 10
New
AstonJ
Backend>Questions

Erlang's not installing on macOS Big Sur "You are natively building Erlang/OTP for a later version of MacOSX than current version"
Just done a fresh install of macOS Big Sur and on installing Erlang I am getting: asdf install erlang 23.1.2 Configure failed. checking ...
#macos/erlang#big-sur#asdf
10 6212 8
New
PragmaticBookshelf
Backend>Learning Resources

Agile Web Development with Rails 7
Rails 7 completely redefines what it means to produce fantastic user experiences and provides a way to achieve all the benefits of single...
pragprog.com
#pragprog#web-development/ruby/rails#published-book/book-agile-web-development-with-rails-7
32 6600 9
New
PragmaticBookshelf
Community>In The Spotlight

Spotlight: Dmitry Zinoviev (Author) Interview and AMA!
Author Spotlight Dmitry Zinoviev @aqsaqal Today we’re putting our spotlight on Dmitry Zinoviev, author of Data Science Essentials in ...
#author-spotlight/python/book-complex-network-analysis-in-python/book-data-science-essentials-in-python/book-resourceful-code-reuse/book-pythonic-programming
33 5211 14
New
hilfordjames
Windows>Chat

Taskbar Overflow Menu (NOT System Tray Overflow)
There appears to have been an update that has changed the terminology for what has previously been known as the Taskbar Overflow - this h...
#taskbar-overflow-win-11
3 3715 2
New
PragmaticBookshelf
Community>In The Spotlight

Spotlight: Bruce Tate (Author) Interview and AMA!
Author Spotlight: Bruce Tate @redrapids Programming languages always emerge out of need, and if that’s not always true, they’re defin...
/elixir/ruby/phoenix/book-seven-more-languages-in-seven-weeks/book-seven-languages-in-seven-weeks#liveview/book-programming-phoenix-liveview
54 5678 23
New
PragmaticBookshelf
General Dev>Learning Resources

A Common-Sense Guide to Data Structures and Algorithms in Python, Volume 1
Big O Notation can make your code faster by orders of magnitude. Get the hands-on info you need to master data structures and algorithms ...
pragprog.com
#pragprog/python#published-book/book-a-common-sense-guide-to-data-structures-and-algorithms-in-python-volume-1
24 5988 11
New
PragmaticBookshelf
Backend>Learning Resources

Engineering Elixir Applications
Develop, deploy, and debug BEAM applications using BEAMOps: a new paradigm that focuses on scalability, fault tolerance, and owning each ...
pragprog.com
#pragprog/elixir#published-book/book-engineering-elixir-applications
40 7136 21
New
Back to top

Latest in Practical Microservices

Practical Microservices Portal ❯

PragProg Customers

Pragmatic Bookshelf PragProg Customers ❯

Latest on Devtalk

Devtalk ❯

We ❤️ helpful members!

We reward our most helpful members via our MOTM scheme - by giving away a whopping 25 books per year!

Member of the Month

Devtalk Sponsors

Pragmatic Bookshelf

Practical resources that improve the lives of professional developers.

Erlang Solutions

We build trusted fault-tolerant systems that scale to billions of users.

Honeybadger

Real-time error tracking, performance insights, and observability for devs.

EEF

Supporting innovation across the BEAM ecosystem.

coders51

We build reliable cloud platforms for business-critical systems.

Manning Publications

Develop your skills with books, videos, and courses.

AppSignal

Catch errors, track performance, monitor hosts and more.

WyeWorks

Enabling companies to succeed by building software people love.

Pragmatic Studio

Courses that move you from confusion to "Aha, now I get it!"

Linux New Media

Publishing Linux Magazine, ADMIN, and MakerSpace for 25+ years.

View all our sponsors ❯

Categories:

Sub Categories:

Popular Portals

Devtalk Sponsors

Pragmatic Bookshelf

Practical resources that improve the lives of professional developers.

Erlang Solutions

We build trusted fault-tolerant systems that scale to billions of users.

Honeybadger

Real-time error tracking, performance insights, and observability for devs.

EEF

Supporting innovation across the BEAM ecosystem.

coders51

We build reliable cloud platforms for business-critical systems.

Manning Publications

Develop your skills with books, videos, and courses.

AppSignal

Catch errors, track performance, monitor hosts and more.

WyeWorks

Enabling companies to succeed by building software people love.

Pragmatic Studio

Courses that move you from confusion to "Aha, now I get it!"

Linux New Media

Publishing Linux Magazine, ADMIN, and MakerSpace for 25+ years.

View all our sponsors ❯

We're in Beta

About us Mission Statement See our Roadmap