The threshold and interval suggestions in suggest-compact.js are written
to stderr via log(). Per the Claude Code hooks guide, non-blocking
PreToolUse stderr (exit code 0) is only captured in the debug log — it
does not reach the model. As shipped, the script's nudge to /compact is
silent on Claude Code 2.1.x.
Fix: alongside the existing log() call (kept for debug-log capture),
emit the same suggestion as structured JSON on stdout:
{ hookSpecificOutput: {
hookEventName: "PreToolUse",
additionalContext: msg
} }
This is the documented mechanism for a PreToolUse hook to inject
context into the next model turn without blocking the tool call.
Verified end-to-end on Claude Code 2.1.142 (VSCode native extension,
Windows 11) — the additionalContext now surfaces in the next turn as
a <system-reminder> block. Counter increment and exit code behavior
unchanged.
Tests: 4 new cases in tests/hooks/suggest-compact.test.js covering
stdout JSON at threshold, stdout JSON at +25 interval, silence below
threshold, and stderr-retention for the debug log. Suite goes from
19/19 -> 23/23 (suggest-compact) and full run-all stays clean for
the unaffected suites (the 4 pre-existing Windows broken-symlink
failures in ci/validators, lib/session-manager, and lib/utils are
unrelated to this change).
- suggest-compact: 'default' session ID fallback when CLAUDE_SESSION_ID empty
- session-aliases: loadAliases backfills missing version and metadata fields
- post-edit-typecheck: valid JSON without tool_input passes through unchanged
Total: 797 tests, all passing
