[rush-daemon][WS2.7][6/9] Forward interactive I/O

[mojaza]

Summary

Adds request-scoped interactive input and terminal-control contracts for rushd, advancing microsoft#5897 after WS2.6.

Depends on #5. This stack follows merged microsoft#5949. PBI: https://onedrive.visualstudio.com/EFun/_workitems/edit/3216023

Details

• Routes request-tagged stdin bytes losslessly with ordered backpressure and strict request isolation.
• Adds acknowledged client-owned raw-mode transitions with deterministic restoration before exact-once command completion.
• Integrates interactive lifecycle with global and phased command routes, including cancellation, disconnect, late-input, and write-failure handling.
• Adds typed terminal capability policy that reports requiresInProcess for commands needing a real controlling terminal.
• Serializes asynchronous incoming frame handlers so transport backpressure reaches the socket.

Limitations

• The daemon does not mutate process stdio, emulate a PTY, or forward SIGWINCH.
• Terminal dimensions remain the immutable request-start context introduced in WS2.5.
• The future WS4 client owns actual in-process fallback, terminal rendering, resize handling, and raw-mode application.
• This remains opt-in and does not add apps/rush or rush-lib launcher integration, WS2.8 scheduling policy, WS2.9 shared-build merging, or WS3 lifecycle behavior.

How it was tested

• node common/scripts/install-run-rush.js test --only @rushstack/rush-daemon-protocol --only @rushstack/rush-daemon-transport --only @rushstack/rush-daemon
• node common/scripts/install-run-rush.js change --verify
• Focused protocol, transport, global/phased router, raw-mode, cancellation, disconnect, backpressure, write-failure, concurrent-isolation, non-UTF-8 stdin, late-input, and terminal-policy tests.

[Copilot]

🟡 Changes recommended

Unresolved issues remain with request-local sink failures, concurrent raw-mode ownership, and consistent asynchronous error handling.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Pull request overview

Adds opt-in interactive I/O support for rushd, including request-scoped stdin, raw-mode controls, terminal policies, and serialized transport handling.

Changes:

• Adds interactive protocol contracts and codecs.
• Integrates input and terminal lifecycle handling.
• Adds transport, router, protocol, and documentation updates.

File summaries

File	Description
libraries/rush-daemon/src/test/RushDaemonHost.test.ts	Host interactive I/O tests
libraries/rush-daemon/src/test/PhasedRequestRouterTestUtilities.ts	Interactive test utilities
libraries/rush-daemon/src/test/PhasedRequestInteractive.test.ts	Phased interactive tests
libraries/rush-daemon/src/test/InteractiveRequestInputRouter.test.ts	Input routing tests
libraries/rush-daemon/src/test/GlobalCommandRequestRouter.test.ts	Global interactive tests
libraries/rush-daemon/src/test/DaemonInteractiveConnection.test.ts	Connection lifecycle tests
libraries/rush-daemon/src/RushDaemonHost.ts	Interactive connection hosting
libraries/rush-daemon/src/PhasedRequestRouter.ts	Phased interactive lifecycle
libraries/rush-daemon/src/PhasedRequestClient.ts	Phased client contract
libraries/rush-daemon/src/InteractiveRequestInputRouter.ts	Request-scoped input routing
libraries/rush-daemon/src/index.ts	Daemon API exports
libraries/rush-daemon/src/GlobalCommandRequestRouter.ts	Global interactive lifecycle
libraries/rush-daemon/src/GlobalCommandRequestClient.ts	Global client contract
libraries/rush-daemon/src/GlobalCommandRequest.ts	Terminal request properties
libraries/rush-daemon/src/GlobalCommandExecutionContext.ts	Child stdin forwarding
libraries/rush-daemon/src/DaemonTerminalPolicy.ts	Terminal policy implementation
libraries/rush-daemon/src/DaemonInteractiveConnection.ts	Connection interactive services
libraries/rush-daemon/src/DaemonControlSession.ts	Interactive frame routing
libraries/rush-daemon/README.md	Interactive behavior documentation
libraries/rush-daemon-transport/src/test/AsyncFrameHandler.test.ts	Async transport tests
libraries/rush-daemon-transport/src/DaemonFrameConnection.ts	Serialized frame handling
libraries/rush-daemon-transport/README.md	Inbound flow-control documentation
libraries/rush-daemon-protocol/src/test/StdinFrameCodec.test.ts	Stdin codec tests
libraries/rush-daemon-protocol/src/test/InteractiveControl.test.ts	Interactive control tests
libraries/rush-daemon-protocol/src/test/ControlFrame.test.ts	Control frame tests
libraries/rush-daemon-protocol/src/StdinFrameCodec.ts	Request-tagged stdin encoding
libraries/rush-daemon-protocol/src/InteractiveControlValidation.ts	Interactive payload validation
libraries/rush-daemon-protocol/src/index.ts	Protocol exports
libraries/rush-daemon-protocol/src/FrameConstants.ts	Stdin framing constants
libraries/rush-daemon-protocol/src/DaemonTerminalPolicy.ts	Terminal policy types
libraries/rush-daemon-protocol/src/DaemonProtocolVersion.ts	Protocol version update
libraries/rush-daemon-protocol/src/DaemonPhasedRequest.ts	Phased terminal requirements
libraries/rush-daemon-protocol/src/DaemonInteractiveControl.ts	Interactive wire contracts
libraries/rush-daemon-protocol/src/DaemonControlMessage.ts	Control message union
libraries/rush-daemon-protocol/src/DaemonControlKinds.ts	Control kind registry
libraries/rush-daemon-protocol/src/DaemonClientCaps.ts	Client capability declaration
libraries/rush-daemon-protocol/src/ControlMessageValidation.ts	Control message validation
libraries/rush-daemon-protocol/README.md	Protocol documentation
common/reviews/api/rush-daemon.api.md	Daemon API report
common/reviews/api/rush-daemon-transport.api.md	Transport API report
common/reviews/api/rush-daemon-protocol.api.md	Protocol API report
common/changes/@rushstack/rush-daemon/mojazayeri-interactive-io_2026-08-21-21-00.json	Daemon change entry
common/changes/@rushstack/rush-daemon-transport/mojazayeri-interactive-io_2026-08-21-21-00.json	Transport change entry
common/changes/@rushstack/rush-daemon-protocol/mojazayeri-interactive-io_2026-08-21-21-00.json	Protocol change entry

Review details

Suppressed comments (5)

libraries/rush-daemon/src/DaemonInteractiveConnection.ts:144

• If a request is cancelled after the setRawMode(true) frame has been sent but before its acknowledgement arrives, the waiter is removed and cleanup queues setRawMode(false) with the same request ID. A client that received the first frame can still acknowledge true; this code then treats that valid late acknowledgement as fatal (the pending entry is either absent or for false) and closes the connection before restoration completes. Keep ordered/tombstoned acknowledgements or otherwise ignore stale acknowledgements from this cancellation race.

  #acknowledgeRawMode(message: IDaemonRawModeChangedMessage): void {
    const acknowledgement: IRawModeAcknowledgement | undefined =
      this.#pendingRawModeByRequestId.get(message.payload.requestId);
    if (!acknowledgement || acknowledgement.enabled !== message.payload.enabled) {
      throw new Error(`Unexpected raw-mode acknowledgement for request "${message.payload.requestId}".`);

libraries/rush-daemon/src/GlobalCommandRequestRouter.ts:94

• This branch runs before the normal global execution cancellation handling. If the client is already aborted but the request declares controllingTerminal, the router still sends requiresInProcess and throws, allowing a thin client to launch fallback for a canceled request rather than publishing an aborted result. Check cancellation before announcing terminal fallback and preserve that precedence across the cleanup await.
  libraries/rush-daemon/src/GlobalCommandRequestRouter.ts:87
• Interactive-session validation runs before terminal policy evaluation. A request that accepts stdin and requires a controlling terminal may legitimately have no daemon input session because it must fall back to in-process execution, but this call throws before the requiresInProcess policy can be emitted. Evaluate the policy first or skip the session requirement for requests rejected by that policy.
  libraries/rush-daemon/src/PhasedRequestRouter.ts:95
• This branch runs before the existing cancellation/admission path. If a phased request is already aborted but declares controllingTerminal, it still publishes requiresInProcess and throws, so the client may start an in-process fallback for a canceled request instead of receiving the normal aborted result. Check cancellation before announcing terminal fallback (and preserve that precedence across the cleanup await).
  libraries/rush-daemon/src/PhasedRequestRouter.ts:87
• Interactive-session validation runs before terminal policy evaluation. A request that accepts stdin and requires a controlling terminal may legitimately have no daemon input session because it must fall back to in-process execution, but this call throws before the requiresInProcess policy can be emitted. Evaluate the policy first or skip the session requirement for requests rejected by that policy.

• Files reviewed: 44/44 changed files
• Comments generated: 3
• Review effort level: Lite

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