Marc Schier 0357380335 Source generator: typed NodeSet method signatures and referenced model accessors (#4124) ...

**Stack 2/5** — base #4123. Part of the #4096 split; see #4096 for the
overall picture.

> Review after #4123. The diff shown against `master` will include #4123
until that merges.

## What this is

Source generator only; no runtime library changes.

## Contents

- **Typed NodeSet method signatures.** A method imported from a NodeSet
now gets a typed signature. Methods that share a declared signature are
grouped onto one generated `MethodType`, named after its owner when the
plain name would collide, so two unrelated `Execute` methods no longer
share a class.
- **An override that keeps the signature it inherits keeps the
declaration it overrides.** Pointing `MethodDeclarationNode` at the
override itself made `MethodDeclarationId` self-referential. OPC 10000-4
lets a caller invoke a method with the NodeId of its declaration in the
ObjectType *or any supertype*, and `MethodState.MethodDeclarationId` is
what the server matches on, so `Call` stopped resolving and returned
`Bad_MethodInvalid` for every alarm subtype. An override that genuinely
changes its signature still becomes its own declaration.
- **`StateNumbers` / `TransitionNumbers` were emitted empty for every
NodeSet-sourced model**, because such children arrive as
`VariableDesign` rather than `PropertyDesign` and were filtered out. Any
companion model built from a NodeSet was writing `StateNumber = 0` on
the wire — a Part 16 defect well beyond the models in this stack. The
ModelDesign path is unchanged.
- **Referenced models can contribute fluent accessors**, carried by a
model dependency payload so a downstream model can extend an upstream
one.

## Notes for the reviewer

- `tests/Opc.Ua.SourceGeneration.Tests` is left at its `master` content
here. Its new vendor-subtype test uses the Robotics NodeSet as its
fixture, so it can only land with the Robotics change at the top of the
stack (5/5).
- `PumpInstanceNodeIdRegressionTests` gains six
`InputArguments`/`OutputArguments` entries for argument-less standard
condition methods. Typed method signatures materialise those properties
from the `ConditionType` declaration even where the method takes none.
That is a real deviation, pinned rather than hidden so it stays visible;
it is worth a follow-up.

## Validation

`dotnet build UA.slnx` — 0 errors.

| Suite | Result |
| --- | --- |
| Opc.Ua.SourceGeneration.Core.Tests | 3739 / 0 |
| Opc.Ua.SourceGeneration.Tests | 81 / 0 |
| Opc.Ua.Di.Tests | 304 / 0 |
| Opc.Ua.History.Tests | 506 / 0 |
| Opc.Ua.Gds.Tests | 1095 / 0 |

History and GDS are listed because they are what the method-declaration
fix above is load-bearing for: without it they fail with 10 and 370
errors respectively.

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 8cbb8cd0-f0cb-4ab0-bea2-6202fbf69485

2026-08-01 07:55:57 +02:00

..

ModelDependencyV1.cs

Source generator: typed NodeSet method signatures and referenced model accessors (#4124)

2026-08-01 07:55:57 +02:00