Both journald receivers import one PRIORITY mapping, and each tier's
suite was asserting the whole table against its own receiver. That checks
one file twice: invert the table and two cases fail saying the same
thing, which tells you nothing about which of the two possible defects
you have.
Split by subject instead. The table's contents — the inverted direction,
overwrite_text, parse_from/on_error — belong to the file that holds them,
so they get a suite of their own reading that file directly, with no
fixture at all. Each tier keeps a case, reduced to the question only it
can answer: does MY receiver carry the shared mapping.
Both tier cases stay. They cover different receivers over different
journals — the agent container's own and the swarm collector's host
journal — and one tier quietly losing its parser while the other keeps
one is exactly the half-fixed state worth catching.
Membership rather than equality of the whole operator list, so a tier
that later grows an unrelated operator of its own still passes.
Checked against seven defect scenarios: each fails exactly one case, and
names the right one.
The direction is the part a reviewer cannot check by looking, so it is
asserted at both ends of the table and in both tiers' groups: an inverted
mapping still maps every value to something, and a case that only asks
whether a severity parser exists passes on the exact defect. The reader
that turns a rendered operator list back into a PRIORITY -> name function
lives in lib.nix, since both tiers need it.
The panel is asserted on its query rather than its title, because a panel
that keeps the title and loses the expression renders an empty graph that
looks exactly like zero prioless lines.
The single module-eval derivation forced ~62 full nixosSystem
fixtures live at once to compute its cases list: 10.6GB peak RSS /
5m25s to evaluate, by far the dominant cost in nix flake check.
Splits it into 21 independent checks.module-eval-* derivations
(1-7 fixtures each) sharing builders/helpers via module-eval/lib.nix,
so no single derivation needs more than a handful of fixtures live
at once. A few cases spanning two clusters carry a small duplicated
fixture rather than threading shared state through lib.nix.
