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?
Marked As Solved
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.
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