[BUG]: Moleculer js called action context is lost #6262
Description
Tracer Version(s)
5.24.0 => 5.62.0
Node.js Version(s)
20.10.0
Bug Report
Moleculer js has a feature where you can set and send back the meta from the called action to the caller , as said in the docs, but dd trace breaks that feature.
Reproduction Code
With these actions as an example
async first(ctx) {
await ctx.call("test.second", null, { meta: {
a: "John"
}});
console.log(ctx.meta);
// Prints: { a: "Doe" }
},
second(ctx) {
// Modify meta
ctx.meta.a = "Doe";
}
Without datadog tracer we get Doe as the value in first action, but when we use dd-trace we still get John.
The reason is the way moleculer js implements the context is they add a ctx property to the returned promise (not value) of the broker call handler result and then the context of the called action is merged with the caller's context.
In our code, patching this code https://github.com/DataDog/dd-trace-js/blob/master/packages/datadog-instrumentations/src/moleculer/client.js#L24 to look like this solves the issue of context being lost, although it is just a hotfix not a proper solution:
promise
.then(
result => {
finishChannel.publish({ broker, ctx })
return result
},
error => {
errorChannel.publish(error)
finishChannel.publish({ broker, ctx })
throw error
}
)
return promise
instead of (original not working code)
return promise
.then(
result => {
finishChannel.publish({ broker, ctx })
return result
},
error => {
errorChannel.publish(error)
finishChannel.publish({ broker, ctx })
throw error
}
)
Error Logs
No response
Tracer Config
No response
Operating System
No response
Bundling
Unsure