Defer reactive cleanup on testServer() exit for the 1.14.0 release#4396
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Defer reactive cleanup on testServer() exit for the 1.14.0 release#4396cpsievert wants to merge 3 commits into
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#4372 made a closing session destroy its bound reactives. testServer() closes its mock session on exit, so reactives created inside a module under test are destroyed as soon as the block returns. Several CRAN packages (blockr.core, blockr.dock, teal.slice) read such reactives after the testServer() block and broke with destroyedReactiveError. Comment out invokeDestroyCallbacks("") in MockShinySession$close() for the 1.14.0 release so the test harness reverts to pre-#4372 behavior. The real ShinySession still destroys on close, so app behavior is unchanged. A detailed note in the source explains how/when to re-enable after notifying the affected maintainers; the paired close-destroys tests are commented out with the same marker.
cpsievert
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Jun 1, 2026
cpsievert
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Jun 1, 2026
cpsievert
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Jun 1, 2026
| # paired tests in tests/testthat/test-destroy.R (search for this same | ||
| # marker) and tests/testthat/test-test-server.R. | ||
| # | ||
| # private$invokeDestroyCallbacks("") |
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After #4395
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| # private$invokeDestroyCallbacks("") | |
| # private$invokeDestroyCallbacks(allowRoot = TRUE) |
This was referenced Jun 1, 2026
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Why this matters
#4372makes a closing session destroy the reactives bound to it. BecausetestServer()closes its mock session on exit, reactives created inside a module under test are now torn down the moment thetestServer()block returns. Three CRAN reverse dependencies — blockr.core, blockr.dock, and teal.slice — read such reactives after thetestServer()block and now fail with"... its module session has been destroyed".To avoid breaking them in the 1.14.0 release, this temporarily reverts the test harness to its pre-
#4372behavior of leaving reactives intact on close.Scope and safety
The change comments out a single line —
invokeDestroyCallbacks("")— inMockShinySession$close(). The realShinySession(ShinySession$wsClosed()) still destroys reactives on close, so application behavior is unchanged; onlytestServer()/MockShinySessionis affected.This is deliberately temporary. A detailed note at the change site explains how and when to re-enable: once the affected maintainers have been notified to adapt their tests (create session-independent reactives with
withReactiveDomain(NULL, ...), or read/snapshot reactive state inside thetestServer()block), uncomment the line and the paired tests, which are commented out behind the same searchable marker intests/testthat/test-destroy.Randtests/testthat/test-test-server.R.Verification
A new test in
test-test-server.Rreproduces the failure (areactiveValuescreated inside a module is read aftertestServer()returns) and passes with the change. Both downstream failure shapes (returning a reactive from atestServer()helper; an external object holding a reactive created insidetestServer()) were confirmed fixed against this branch.