What Problem This Solves

TranscriptsStore.readUtterancesFromDir creates a createReadStream and readline.createInterface inline inside a try block for streaming JSONL parsing. If JSON.parse throws on a malformed line, the catch block re-throws the error but the stream and readline interface are never cleaned up — the underlying file descriptor remains open until garbage collection.

In long-running gateway processes that parse many transcript sessions, leaked file descriptors accumulate and can exhaust the OS fd limit.

Why This Change Was Made

The stream and readline references were created inline inside the try block, making them unreachable from catch or any cleanup path. By extracting them to outer-scope variables and adding a finally block that calls lines.close() and stream.destroy(), the file descriptor is released immediately on all exit paths — normal completion, parse error, or ENOENT.

User Impact

Operators running OpenClaw gateways with active transcript sessions will no longer accumulate leaked file descriptors when malformed JSONL lines are encountered. This prevents potential EMFILE errors in long-running processes.

Evidence

• Behavior addressed: File descriptor leak in readUtterancesFromDir when JSON.parse throws on malformed JSONL
• Environment tested: macOS, Node.js v22.22.3, OpenClaw 2026.6.11 (5d52b5b)
• Steps run after the patch: Created a test JSONL file with valid lines + one malformed line, exercised the streaming parse path with try/finally cleanup
• Evidence after fix: Stream is properly destroyed after parse error:

Parse error caught: Unexpected token 'N', "NOT_VALID_JSON{{{" is not valid JSON
finally: lines.close() + stream.destroy() called
Stream destroyed: true
Stream readable: false
File unlinked successfully (FD released)
Test PASSED: stream cleanup on parse error works correctly

• Observed result after fix: stream.destroyed === true, stream.readable === false, file descriptor released immediately
• What was not tested: Production gateway with real transcript accumulation over time; only single-file parse-error path verified

Real behavior proof

• Behavior addressed: File descriptor leak in readUtterancesFromDir when JSON.parse throws on malformed JSONL
• Environment tested: macOS, Node.js v22.22.3, OpenClaw 2026.6.11 (5d52b5b)
• Steps run after the patch: Created a test JSONL file with valid lines + one malformed line, exercised the streaming parse path with try/finally cleanup
• Evidence after fix: Stream is properly destroyed after parse error:

Parse error caught: Unexpected token 'N', "NOT_VALID_JSON{{{" is not valid JSON
finally: lines.close() + stream.destroy() called
Stream destroyed: true
Stream readable: false
File unlinked successfully (FD released)
Test PASSED: stream cleanup on parse error works correctly

• Observed result after fix: stream.destroyed === true, stream.readable === false, file descriptor released immediately
• What was not tested: Production gateway with real transcript accumulation over time; only single-file parse-error path verified

Changes Made

• src/transcripts/store.ts: Extract createReadStream and createInterface to outer scope variables; add finally block with lines.close() and stream.destroy() to ensure cleanup on all exit paths

• AI-assisted (Hermes Agent)