The original three-stage design (probe / driver-loopback / forward-
bridge) only proved driver-write → server-read. It missed:
- OPC UA write → server → driver → PLC (the reverse direction)
- server-side data-change notifications actually firing (a stale
subscription can still let a read-after-the-fact return the new
value and look fine)
Extend _common.ps1 with two helpers:
- Test-OpcUaWriteBridge: otopcua-cli write the NodeId -> wait 3s ->
driver CLI read the PLC side, assert equality.
- Test-SubscribeSeesChange: Start-Process otopcua-cli subscribe in the
background with --duration N, settle 2s, driver-side write, wait for
the subscription window to close, assert captured stdout contains
the new value.
Wire both into test-modbus / test-abcip / test-ablegacy / test-s7 /
test-focas / test-twincat after the existing forward-bridge stage.
Update README to describe the five-stage design + note that the
published NodeId must be writable for stages 4 + 5.
Also prepend UTF-8 BOM to every script in scripts/e2e so Windows
PowerShell 5.1 parsers agree on em-dash byte sequences the way
PowerShell 7 already does. The scripts still #Requires -Version 7.0 —
the BOM is purely defensive for IDE / CI step parsers.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
