Port validation and lifecycle fixes to Node, Python, and Go

[stephentoub]

C# recently tightened generated RPC argument validation and session lifecycle cleanup. This ports the commensurate behavior to the SDKs that had matching gaps so clients fail earlier, do not keep stale active sessions around, and reject duplicate active local sessions consistently.

Summary

• Updates the TypeScript, Python, and Go RPC generators so generated session APIs validate required params before sending and reject session-scoped RPC calls after disconnect.
• Cleans up Node, Python, and Go session/client lifecycle handling: direct disconnect unregisters from the parent client, stop/force-stop/delete paths clear active session maps safely, and duplicate active session IDs are rejected.
• Adds focused lifecycle and generated-RPC regression coverage, plus adjusts Go e2e resume coverage for the new duplicate-active-session contract.

Rust was reviewed but left unchanged because its existing ownership/lifecycle model already covers the comparable behavior.

Validation

• cd nodejs && npm run typecheck
• cd nodejs && npm test -- client.test.ts --testNamePattern "directly disconnected|reports stop errors|replacement session|duplicate active|validates required"
• cd python && python -m pytest -q test_client.py test_rpc_generated.py
• cd python && python -m ruff check test_client.py test_rpc_generated.py copilot\client.py copilot\session.py
• cd go && go test -timeout 20m ./...
• git diff --check

[Copilot]

Pull request overview

This PR ports stricter generated-RPC argument validation and session lifecycle cleanup (previously tightened in C#) to the Node.js, Python, and Go SDKs, so clients fail earlier on invalid usage and don’t retain stale/duplicate active sessions.

Changes:

• Updated TS/Python/Go RPC generators (and regenerated outputs) to validate required request objects before sending and to reject session-scoped RPC calls once a session is disconnected.
• Hardened session/client lifecycle cleanup across Node/Python/Go (disconnect unregisters from the owning client; stop/force-stop/delete ensure sessions are marked unusable; duplicate active session IDs are rejected).
• Added/updated targeted unit + E2E regression coverage to lock in lifecycle/validation behavior, including updated Go resume tests for the new “duplicate active session” contract.

Show a summary per file

File	Description
scripts/codegen/typescript.ts	Emit session “active” assertions and required-params checks in generated TS RPC methods.
scripts/codegen/python.ts	Emit session “active” assertions and required-params checks in generated Python RPC methods.
scripts/codegen/go.ts	Emit session “active” assertions and required-params checks in generated Go RPC methods.
python/test_rpc_generated.py	Adds regression tests for required-params validation and active-check behavior.
python/test_client.py	Adds/updates lifecycle tests for disconnect/unregister, duplicates, and failure cleanup paths.
python/copilot/session.py	Implements disconnect idempotency + active-use rejection; clears handlers/hooks on disconnect and supports unregister callback.
python/copilot/generated/rpc.py	Regenerated RPC surface with params validation and assert-active hooks for session APIs.
python/copilot/client.py	Adds session registration helpers; enforces duplicate-active rejection and consistent cleanup on stop/force-stop/delete.
nodejs/test/client.test.ts	Adds unit coverage for lifecycle cleanup, stop errors, duplicate registration, and params validation.
nodejs/src/session.ts	Adds disconnect state, active assertions, idempotent disconnect, forced-disconnect hook, and unregister callback.
nodejs/src/generated/rpc.ts	Regenerated RPC surface with params validation and assert-active hooks for session APIs.
nodejs/src/client.ts	Enforces duplicate-active session IDs; ensures stop/force-stop/delete mark sessions disconnected and clears internal RPC state.
go/session.go	Adds session active-state tracking, idempotent Disconnect, and client unregister on disconnect; rejects usage after disconnect.
go/session_test.go	Adds unit tests covering lifecycle cleanup and duplicate-active session registration behavior.
go/rpc/zrpc.go	Regenerated Go RPC surface with params validation and assert-active checks for session APIs.
go/rpc/generated_rpc_api_shape_test.go	Adds regression tests for required-params validation and active-check ordering.
go/internal/e2e/session_e2e_test.go	Updates E2E expectations for post-disconnect behavior and validates duplicate-active resume rejection; adds resume-client helper.
go/internal/e2e/session_config_e2e_test.go	Updates resume scenarios to use a separate TCP client consistent with the new “active session” contract.
go/internal/e2e/permissions_e2e_test.go	Updates resume permissions scenario to use separate resume client and aligns with new join behavior.
go/internal/e2e/mcp_and_agents_e2e_test.go	Updates resume scenarios to use separate resume client (TCP mode).
go/internal/e2e/commands_and_elicitation_e2e_test.go	Updates resume scenario to use separate resume client (TCP mode).
go/client.go	Enforces duplicate-active session IDs and centralizes session snapshot/clear helpers; ensures stop/force-stop disconnects and marks sessions unusable.

Copilot's findings

Files not reviewed (1)

• go/rpc/zrpc.go: Language not supported

• Files reviewed: 19/22 changed files
• Comments generated: 2

[github-actions]

Generated by SDK Consistency Review Agent for issue #1341 · ● 2.6M

[github-actions]

Cross-SDK Consistency Review ✅

This PR ports C# validation and lifecycle fixes to Node.js, Python, and Go. I reviewed the changes across all five SDK implementations for consistency. Overall, the PR is well-executed and brings the three modified SDKs into alignment with the .NET baseline.

Verification Summary

Feature	.NET (source)	Node.js	Python	Go	Rust
Duplicate active session rejection	RegisterSession → TryAdd throws	✅ registerSession → throws if different object	✅ _register_session → throws if different object	✅ registerSession → returns error if different object	N/A — ownership prevents duplicates
Session-scoped RPC rejects after disconnect	_session.ThrowIfDisposed() in generated Rpc.cs	✅ assertActive?.() in generated rpc.ts	✅ assert_active() in generated rpc.py	✅ assertActive in zrpc.go	N/A — ownership model covers this
Session methods reject after disconnect	ThrowIfDisposed() in send/on/rpc/ui	✅ assertActive() in send/on/rpc/ui	✅ _assert_not_destroyed() in send/on/rpc/ui	✅ assertActive() in Send/SendAndWait	N/A
Session disconnect unregisters from parent client	RemoveFromClient() in DisposeAsync	✅ onDisconnected callback	✅ _on_disconnected callback	✅ owner field + unregisterSession	✅ Drop impl calls unregister_session
Stop clears sessions safely (snapshot then clear)	Snapshot via _sessions.Values.ToArray()	✅ [...this.sessions.values()] snapshot	✅ list(self._sessions.values()) snapshot	✅ snapshotSessions() helper	✅ router snapshot

One Minor Observation (pre-existing .NET gap, not introduced here)

.NET's ForceStopAsync only calls _sessions.Clear() without marking the cleared sessions as disposed — it relies on the transport closure to cause ObjectDisposedException on any subsequent RPC calls. By contrast, this PR's additions to Node, Python, and Go explicitly call _markDisconnected() / session.markDisconnected() on sessions cleared by force_stop. This is strictly a net improvement (cleaner error messages) rather than a consistency problem. If desired, .NET's ForceStopAsync could similarly mark sessions disposed, but that's a pre-existing gap outside this PR's scope.

Retry Logic Removal (Node.js stop())

Node's old stop() had a 3-attempt exponential backoff not present in other SDKs. Removing it aligns Node with .NET, Python, and Go — ✅ correct.

Rust

The PR's assertion that Rust's existing ownership/lifecycle model covers the comparable behavior is correct: Session is returned by value (!Clone), Drop unregisters via unregister_session, and router.register() overwrites a prior entry only when a new Session value is created (which can't coexist with a live prior one). No change needed there.

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The changes are consistent across all languages. No cross-SDK gaps introduced by this PR.

Generated by SDK Consistency Review Agent for issue #1341 · ● 1.3M · ◷