`graphify explain "<node>"` sorts a node's connections by neighbor
degree and shows only the top 20, appending a bare "... and N more"
for the rest. On a high-degree node (a logging/error helper called
from dozens of places is typical) that leaves the exact question
explain is meant to answer - "who calls this, what's the impact?" -
unanswered for 97% of the callers, with nothing pointing at where
they live (#2009).
The top-20 list and its ordering are unchanged (no behavior change
for nodes at or under the cutoff). Past it, the cut connections are
now grouped by (direction, source_file) with counts and printed
under a "Grouped by file:" section, sorted by count descending, so
the caller/callee distribution is visible without falling back to a
repo-wide grep. The aggregation itself is capped at 20 files with
its own "... and N more files" line for the pathological case where
the remainder is spread across more files than that.
Full per-caller detail behind a flag (--callers --all / --group-by=dir
as proposed in the issue) is left for a follow-up: it's a larger,
more opinionated surface (flag naming, pagination semantics) than
the literal complaint needs, and the default output no longer hides
the answer either way.
Four regression tests in tests/test_explain_cli.py: the pre-existing
truncation notice on a 30-connection node is unchanged, the grouped-
by-file output carries real counts (3 files, one at 4 and two at 3)
that sum back to exactly the cut total (no silent loss), a
byte-for-byte no-op check for nodes at/under the cutoff, and a
boundary check pinning the cutoff itself at exactly 20 connections
(no section) vs exactly 21 (one grouped entry) — the earlier tests
sit well clear of the edge and wouldn't catch a future off-by-one.
Yyunozor
0ef452c570