Fix flaky TestPerCursorReads via atomic meta updates#11
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Concurrent LoadMeta → modify → SaveMeta cycles could overwrite each other's changes. When captureOutput cleanup saved session state, it could clobber cursor positions written by handleRead, causing reads to restart from position 0. - Add UpdateMeta to OutputStorage interface (atomic read-modify-write under lock) - Implement in MemoryStorage (mutates in-place under lock) and FileStorage (load-mutate-save under lock) - Replace all LoadMeta/SaveMeta pairs in server.go with UpdateMeta calls - Affects: captureOutput cleanup, handleRead, handleReadTUI, handleStop, handleResize
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Bug
TestPerCursorReadsfails intermittently on CI (Linux) because concurrent meta update paths can overwrite each other's changes. WhencaptureOutputcleanup saves session state, it replaces the entire meta object, clobbering cursor positions thathandleReadjust wrote. The next read then starts from position 0 and returns duplicate content.Solution
An
UpdateMetamethod on theOutputStorageinterface performs atomic read-modify-write under a single lock. Each call site only mutates the fields it owns (cursors, state, dimensions), so concurrent updates no longer overwrite unrelated fields.Changes
Storage interface (
storage.go,storage_memory.go,storage_file.go):UpdateMeta(session, func(meta))added to interface and both implementationsServer (
server.go):captureOutputcleanup,handleStop: useUpdateMetafor state transitionshandleRead,handleReadTUI: useUpdateMetafor cursor/position updateshandleResize: useUpdateMetafor dimension updates