Bug in BuildVariant (opcua-iiot-core.ts): Values like 0, 0.0, or false result in null (or NaN) values

[dei-p4i]

Which node-red-contrib-iiot-opcua version are you using?

4.0.9

What happened?

We encountered getting #NaN as values on our OPC UA Server, when using the write node, if the value was 0.0. Further testing showed that also 0 (for int types) and false (for boolean) resulted in null errors. Note: Before updating to 4.0.9 we used a 3.x.x version without that problem (don't remember exact version)

I found a probable problematic line of code in the package source: the if-test in the beginning of buildNewVariant in /src/core/opcua-iiot-core.ts:

  let variantValue: VariantOptions = {
    dataType: DataType.Null,
    value: null
  }
  // Possible bug location:
  // javascript interprets 0, 0.0 and false (or empty arrays or ...) here as false, so value stays "null"
  if (value.value)
    value = value.value

Server

OPCUA-IIoT-Flex-Server Node (Please attach AddressSpaceScript to the next section)

How can this be reproduced?

Zipped Demo with Flex-Server using (slightly modified) original addressSpace code: demo-iiot-opcua-zero-value-bug.json.zip

• Set value to 1.0 by inject => read by inject => value is 1.0
• Set value to 0.0 by inject => read by inject => value is null

What did you expect to happen?

Value should be 0.0 (or 0 or false depending on used data type)

Other Information

No response

[biancode]

It would be good to have tests for this issue.

[CW0815]

opc.tcp://milo.digitalpetri.com:62541/milo ns=2;s=CTT/Static/All Profiles/Scalar/Int16

Write Set value to 1 by inject (value is 1) Set value to 0 by inject ("Error: expecting a number NaN") Set value to "0" by inject (value is 0)

Read read 1 by inject (msg.payload.value[0].value is 1) read 0 by inject (msg.payload.value[0].value.value is 0)

[biancode]

We working on a version 4.1 - we found a lot issues after the TS merge, which are to be fixed soon.

[CW0815]

same problem with version 4.1

opc.tcp://milo.digitalpetri.com:62541/milo ns=2;s=CTT/Static/All Profiles/Scalar/Int16

Write Set value to 1 by inject (value is 1) Set value to 0 by inject ("Error: expecting a number NaN") Set value to "0" by inject (value is 0)

Read read 1 by inject (msg.payload.value[0].value is 1) read 0 by inject (msg.payload.value[0].value.value is 0)

[biancode]

We did not work on that for now. Maybe we have it next week in our next release.

[biancode]

@JoelKrec we should include this as a test in the package.

[biancode]

v4.1.1 actual test - release soon

[biancode]

Test Flow to implement in e2e testings

TestFlowZeroValueBug.json.zip

[CW0815]

v4.1.1 the value is null, but with "OPCUA-IIoT-Inject" + "function" the value is 0

msg.payload.nodetype = 'inject'; msg.payload.injectType = 'write'

msg.payload.valuesToWrite = []; msg.payload.valuesToWrite[0] = "0";

return msg;

TestFlowZeroValueBug02.zip

[biancode]

@CW0815 give v4.1.2 a try

[CW0815]

This works with v4.1.2

But with a Response between Read and helper, the output is different at 0 and 1.

[biancode]

The response node is not working very well after the shift to TypeScript. See the TODO.md for more information.

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