Testing opcilloscope

The suite has three layers and uses only .NET plus the operating-system facilities noted below.

1. Unit / integration tests (existing)

Tests/Opcilloscope.Tests/ — xUnit tests for the OPC UA, configuration, theming and utility layers, plus integration tests against the in-process Opcilloscope.TestServer.

dotnet test Opcilloscope.sln
dotnet test Tests/Opcilloscope.Tests/Opcilloscope.Tests.csproj \
  --filter "FullyQualifiedName~Integration"

The solution contains the cross-platform unit, integration, and component tests. The Linux-only black-box project is invoked explicitly as described in layer 3.

2. In-process TUI component tests

Tests/Opcilloscope.Tests/Tui/ — constructs the real Terminal.Gui views and dialogs (MonitoredVariablesView, ConnectDialog, the theme/Scheme system, …) and asserts on their observable behaviour and state.

dotnet test Tests/Opcilloscope.Tests/Opcilloscope.Tests.csproj \
  --filter "FullyQualifiedName~Tui"

These tests live in a non-parallel xUnit collection ([Collection("Tui")]) because the app's TerminalUi.App reference and Terminal.Gui theme/driver state are process-global and must not be shared across parallel tests.

Why these assert on state, not rendered cells. Terminal.Gui 2.4.5 (stable) does not expose a public headless driver: Application.Create() leaves Driver null until the real console event loop runs, and the cell-buffer assertion helper (DriverAssert) only exists on the upstream develop branch. Assertions on the rendered screen are therefore done by layer 3 (below), which drives the real published binary. When upstream ships a public test driver, these component tests can add cell-level snapshots.

3. Black-box end-to-end (PTY) tests

Tests/Opcilloscope.E2ETests/ — launches the published binary attached to a sized Linux pseudo-terminal, reconstructs the rendered screen from the VT/ANSI output, and asserts on it. The harness uses .NET plus Linux libc (openpty/posix_spawn); it needs no Node, Python, script, or external terminal emulator.

# Linux only; creates and removes a fresh temporary publish:
dotnet test Tests/Opcilloscope.E2ETests/Opcilloscope.E2ETests.csproj

# Or exercise one exact pre-published artifact, as CI does:
OPCILLOSCOPE_BIN="$PWD/publish/opcilloscope" \
  dotnet test Tests/Opcilloscope.E2ETests/Opcilloscope.E2ETests.csproj

The project intentionally stays out of Opcilloscope.sln, preserving normal solution builds and tests on macOS and Windows. If OPCILLOSCOPE_BIN is set but missing, the suite fails rather than silently publishing a different binary.

See Tests/Opcilloscope.E2ETests/README.md for details and CI notes.