fix: loadedMessage is not cleared after message(s) handled

[jtarvainen]

Environment

• HL7 Client version: 2.3.1
• HL7 Server version: 2.4.1

Questions:

• Are you using the Node HL7 Server package as your HL7 Server to connect to or a 3rd party system?

Yes

Expected Behavior

The Inbound instance's "data" event handler should clear loadedMessage after handling a complete message (or batch of messages). Otherwise the variable just keeps concatenating each received message in perpetuity.

Actual Behavior

loadedMessage is never cleared, causing each previously received message to be re-handled upon reception of each new message.

The fix is to add the following after row 220 in src/server/inbound.ts:

loadedMessage = '';

Steps to reproduce the bug

Create a unit test where:

1. Client initiates a connection to the server
2. Client sends a message to the server and waits for a response (connection is kept open!)
3. Client sends a second message to server and waits for a response
4. Client closes the connection to the server

Assert that in step #3 the previously sent message is re-handled on the server in addition to the new message and two acknowledgments are sent to the client instead of one.

[Bugs5382]

@jtarvainen My coding days are tomorrow. I will work on this and release the other feature for AE.

[Bugs5382]

So doing so breaks up a unit test for very large messages, like getting PDF data.

node-hl7-server/src/server/inbound.ts

Line 139 in 9eb9a20

let loadedMessage: string = ''

Already has clearing of the loadedMessage on a TCP connect. I might have to write a unit test out for this one to test out this issue.

[Bugs5382]

This could be a bug in the node-hl7-client as well.

[jtarvainen]

The client device we use keeps the TCP connection alive between messages, so we can't rely on the clear-on-connect feature.

[Bugs5382]

@jtarvainen Just so you know, I am trying to nail this down. Some major testing I been writing locally.

[jtarvainen]

@Bugs5382 Any update on this? I haven't investigated the code further, but to me it sounds like it should be OK to clear loadedMessage after the current message (or batch of messages) has been fully processed, even if it contains PDF data?

[Bugs5382]

@jtarvainen I am still working. I tried that, and my unit tests failed hard. Maybe I am missing something.

[Bugs5382]

This fix is going to be out soon. Thanks @jtarvainen for your patience.

[Bugs5382]

@jtarvainen This has been release 3.0.1-develop

[jtarvainen]

That's great, thank you!