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

jimmykiang
PragProg Customers

Distributed Services With Go - Agent_test.go error line 77
This test is broken right out of the box… — FAIL: TestAgent (7.82s) agent_test.go:77: Error Trace: agent_test.go:77 agent_test.go:...
#errata/book-distributed-services-with-go
4 1559 7
New
iPaul
PragProg Customers

The Definitive ANTLR 4 Reference: Program deprecation warning
page 37 ANTLRInputStream input = new ANTLRInputStream(is); as of ANTLR 4 .8 should be: CharStream stream = CharStreams.fromStream(i...
#errata/book-the-definitive-antlr-4-reference
4 987 0
New
belgoros
PragProg Customers

Effective Testing with RSpec 3: Running Sequel migrations fails (page 84)
Following the steps described in Chapter 6 of the book, I’m stuck with running the migration as described on page 84: bundle exec sequel...
#errata/book-effective-testing-with-rspec-3
4 1152 1
New
GilWright
PragProg Customers

Apple Game Frameworks and Technologies: Screen image may be wrong (p 13)
Working through the steps (checking that the Info,plist matches exactly), run the demo game and what appears is grey but does not fill th...
#errata/book-apple-game-frameworks-and-technologies
11 1081 5
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
Mmm
PragProg Customers

Hands-on Rust: Build depending on bracket-lib fails
Hi, build fails on: bracket-lib = “~0.8.1” when running on Mac Mini M1 Rust version 1.5.0: Compiling winit v0.22.2 error[E0308]: mi...
#question/book-hands-on-rust
1 1218 1
New
swlaschin
PragProg Customers

Domain Modeling Made Functional: Missing diagram on page 18
The book has the same “Problem space/Solution space” diagram on page 18 as is on page 17. The correct Problem/Solution space diagrams ar...
#errata/book-domain-modeling-made-functional
1 1078 1
New
brian-m-ops
PragProg Customers

Python Testing with pytest, Second Edition: cards pip install error (page 12)
#book-python-testing-with-pytest-second-edition Hi. Thanks for writing the book. I am just learning so this might just of been an issue ...
#errata/book-python-testing-with-pytest-second-edition
4 1191 3
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
adamwoolhether
PragProg Customers

Powerful Command-Line Applications in Go: Exercise Solutions (many pages)
Is there any place where we can discuss the solutions to some of the exercises? I can figure most of them out, but am having trouble with...
#question/book-powerful-command-line-applications-in-go
17 1396 9
New

Other popular topics Top

PragmaticBookshelf
Backend>Learning Resources

Web Development with Clojure, Third Edition
Stop developing web apps with yesterday’s tools. Today, developers are increasingly adopting Clojure as a web-development platform. See f...
pragprog.com
#pragprog#web-development/clojure#published-book/book-web-development-with-clojure-third-edition
5 4584 1
New
PragmaticBookshelf
Backend>Learning Resources

Programming Machine Learning
Machine learning can be intimidating, with its reliance on math and algorithms that most programmers don't encounter in their regular wor...
pragprog.com
#pragprog#ai/python#published-book/book-programming-machine-learning#math#algorithms
6 5350 3
New
siddhant3030
General Dev>Dev Chat

Which vertical monitor do you use?
I’m thinking of buying a monitor that I can rotate to use as a vertical monitor? Also, I want to know if someone is using it for program...
#monitors#programming
51 4892 20
New
Rainer
Community>Journals

Programming Erlang Book Club
My first contact with Erlang was about 2 years ago when I used RabbitMQ, which is written in Erlang, for my job. This made me curious and...
/erlang/book-programming-erlang-2nd-edition#book-club
195 6815 95
New
AstonJ
General Dev>Hardware

BIIP MT3 Extended 2048 Custom Keycap Set (Drop)
This looks like a stunning keycap set :orange_heart: A LEGENDARY KEYBOARD LIVES ON When you bought an Apple Macintosh computer in the e...
/keyboards#apple#keycaps#mechanical-keyboards
14 6713 7
New
rustkas
Backend>Chat

Using Regular Expressions in Erlang
Intensively researching Erlang books and additional resources on it, I have found that the topic of using Regular Expressions is either c...
/erlang#regular-expressions
91 5662 43
New
AstonJ
Science/Tech>Health & Diet

David Sinclair's new Lifespan podcast
We’ve talked about his book briefly here but it is quickly becoming obsolete - so he’s decided to create a series of 7 podcasts, the firs...
#health#podcasts#bio-hackers#david-sinclair
87 6790 49
New
PragmaticBookshelf
Backend>Learning Resources

Agile Web Development with Rails 8
Get the comprehensive, insider information you need for Rails 8 with the new edition of this award-winning classic. Sam Ruby @rubys ...
pragprog.com
#pragprog#web-development/ruby/rails#published-book/book-agile-web-development-with-rails-8
12 7404 7
New
AnfaengerAlex
Android>Questions

Unresolved Reference to android in build.gradle.kts – Beginner Issue
Hello, I’m a beginner in Android development and I’m facing an issue with my project setup. In my build.gradle.kts file, I have the foll...
#binding
0 7460 2
New
AstonJ
AI>In The News

DeepSeek (671B) running on a cluster of 8 Mac Mini Pros with 64GB RAM each
This is cool! DEEPSEEK-V3 ON M4 MAC: BLAZING FAST INFERENCE ON APPLE SILICON We just witnessed something incredible: the largest open-s...
#ai#macs/deepseek
0 6695 1
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