feat: opt-in hard-disconnect via session$close(hard = TRUE)#4398
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elnelson575 wants to merge 20 commits into
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feat: opt-in hard-disconnect via session$close(hard = TRUE)#4398elnelson575 wants to merge 20 commits into
elnelson575 wants to merge 20 commits into
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Captures the design for shinyApp(hardDisconnect = TRUE): in-process teardown of root inputs/clientData/downloads/files, handshake-time hosting-layer signal, and a distinct client-side closed state. Includes the brief for the Shiny Server / Connect teams describing the contract they would need to honor.
…meout Captures the design for two opt-in hard-disconnect pathways in Shiny: - session$close(hard = TRUE, message = ...) for author-triggered ends - shinyApp(hardDisconnectAfter = N) for idle timeout No app-wide "every disconnect is hard" mode; the natural-disconnect path stays soft. Also elevates session$close() to documented public API. Covers the in-process teardown of root inputs/clientData/ downloads/files, the 4001 close code as the hosting-layer signal, and a distinct client-side closed state, plus a brief for the Shiny Server / Connect teams describing the contract they would need to honor.
After reviewing shiny-server's architecture (specifically lib/scheduler/worker-entry.js), confirm the idle-timeout belongs in Shiny rather than delegated to the platform: shiny-server tracks connection counts, not per-session activity, and adding active-idle tracking would require substantial new machinery in the proxy. Captures this in a "Why Shiny implements this" subsection and sharpens the hosting handoff brief with the concrete code change needed in shiny-server (treat close code 4001 as equivalent to app_idle_timeout = 0 for that worker).
Tasks for the per-call hard-close primitive: hardDisconnectMessage arg on shinyApp(), session$close(hard, message), wsClosed teardown extension, custom-message handler + onclose 4001 check on the client, closed-overlay SCSS, NEWS entry. Plan B (idle timeout) deferred to a follow-up branch off this work.
Add private fields hardDisconnectMessage and wasHardClose to ShinySession. Read hardDisconnectMessage from shinyOptions during initialize().
Replace withr::with_options(list(), {...}) wrappers with withr::defer()
calls. The with_options wrapper only affects base::options(), not
shinyOptions which are stored in .globals$options. Using withr::defer()
to reset the shinyOption at end-of-test provides actual cleanup isolation.
…them
Add clarifying comment explaining why destroyByPrefix("") is used instead
of destroy() (avoids marking the container as destroyed). In the test,
pre-populate .input and .clientData so the expect_length assertions are
non-vacuous and actually verify that destroyByPrefix("") clears the keys.
Add CSS for the closed overlay introduced in Task 8, using a fully opaque white card centered on screen to communicate finality, visually distinct from the transient grey-haze disconnected overlay.
Move hardDisconnectConfig from the user-facing addCustomMessageHandler path (where a user app could silently override Shiny's handler by registering a custom handler with the same name) to the internal addMessageHandler path used for other built-in protocol messages like allowReconnect. addMessageHandler throws on duplicate registration, protecting the feature from accidental collision.
Adds browser-driven tests covering what the R unit tests can't: - close_hard renders #shiny-closed-overlay with the per-call message - close_app_default falls back to shinyApp(hardDisconnectMessage =) - close_soft preserves today's #shiny-disconnected-overlay (regression) - submit-and-exit pattern: modal first, then closed overlay - shiny:closed jQuery event fires with the correct detail.message Listens via jQuery .on() rather than document.addEventListener because $(document).trigger(...) only reaches jQuery handlers — consistent with the rest of Shiny's event surface.
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Summary
Adds an opt-in hard-disconnect mode to Shiny. App authors can now call
session$close(hard = TRUE, message = ...)to perform a complete session teardown — useful for "submit and exit" / "log out" flows and end-user-visible "this app has closed" experiences. The teardown runs in three coordinated tiers:wsClosed()clears the rootinputs,clientData,downloads, andfilescollections (which the existing destroy walk intentionally skips for the soft path) and drops theSessionProxyreference.4001and reason"shiny-hard-disconnect", which Shiny Server / Posit Connect can recognize as "release this worker, no reconnect grace period."#shiny-closed-overlayreplaces the grey#shiny-disconnected-overlay; the page becomes inert; ashiny:closedjQuery event fires with the author's message indetail.message; iframe parents receive"closed"postMessage.Default text for the closed overlay can be set app-wide via
shinyApp(hardDisconnectMessage = ...)and overridden per-call. Default behavior is unchanged —session$close()with no arguments performs today's soft close byte-for-byte.This is Plan A of a two-part split. Plan B (idle timeout via
shinyApp(hardDisconnectAfter = N)) will follow on a separate branch off this work, building on this primitive — Plan A ships standalone.Design and plan documents
Spec:
docs/superpowers/specs/2026-06-03-hard-disconnect-design.mdImplementation plan:
docs/superpowers/plans/2026-06-03-hard-disconnect-per-call.mdShiny Server / Connect coordination
The spec includes a brief asking the hosting platforms to honor close code
4001as equivalent toapp_idle_timeout = 0for that worker (one-line change inlib/scheduler/worker-entry.js'sstartIdleTimer()). Without this change, in-process teardown and client UX still work; only the worker-pool release optimization is partial. The brief is in the spec, ready to share.Notable deviation from spec
Spec described the runtime config message under the
customenvelope ({"custom":{"hardDisconnectConfig":...}}). Final implementation sends it at the top level ({"hardDisconnectConfig":...}) and registers via internaladdMessageHandlerinstead of user-facingaddCustomMessageHandler— that protects the handler from being silently overridden by a user app registering a custom handler with the same name. Caught during code review (final-pass I1), wire format verified with a real WebSocket driver before merge.Test plan
tests/testthat/test-hard-disconnect.R)srcts/src/shiny/__tests__/hardDisconnect.test.ts)tests/testthat/test-hard-disconnect-shinytest2.Rcovering closed-overlay rendering, app-default fallback, soft-close regression, and the submit-and-exit patternR CMD check: 0 errors, 0 warningshardDisconnectConfig+ close code4001on hard close, code1000+ empty payload on soft close (unchanged from today)#shiny-disconnected-overlaystill appears on natural disconnects andsession$close()(no args)Reviewer notes
shiny:closedis a jQuery event ($(document).trigger(...)). Listeners usingdocument.addEventListenerwill not receive it — same convention as existingshiny:connected/shiny:disconnected. Worth a doc mention in NEWS or session help if the team wants vanilla-JS listeners to be discoverable; left out of this PR to keep scope tight.devtools::install()) for shinytest2's child process to pick up the new arguments — same requirement as the existingtest-zzz-st2-download.R.