Two production maps paint the doxa-regions layers directly -- 35
setPaintProperty('regions-fill'|'regions-border') calls between them, 10 in one
file and 25 in the other. Twenty-one pass their value through a one-line helper
that wraps it in the same ['case', ['has','iso_3166_1_alpha_3'], v, v]
expression, and each map defined its OWN copy of that helper while already
passing it into the library composable that paints with it. The library owned
the paint logic and not the expression, so the two copies could be edited apart
and the same "idle" would render differently on the two maps, with nothing
failing. No existing check covers this: the nearest one reads a different
component entirely.
The gate asserts the idle paint is single-sourced: the library exports the
helper, neither map keeps a local definition, and neither inlines the
expression. It deliberately does NOT require all 35 writes to route through the
library. The raw multi-line writes are highlight states and outline resets that
differ by design and by map; demanding uniformity there would make this red on
the day it was written, which is how a gate earns being ignored. It also does
not assert how OFTEN each map repaints -- one repaints the idle state more
than the other and has a dynamic call the other lacks. That is a real
difference in when, and flattening it is how a map goes blank. This checks that
the maps agree on what idle looks like, never on how often they say it.
Two-sided. Poisoning it un-exports the library helper and re-inlines a local
copy in a consumer; three assertions flip from ok to FAIL, each catching its
own planted regression, and the run exits 1.
Registered but NOT chained yet: it is legitimately red until the second map
adopts the library helper, and chaining a red gate would break the shared run
for everyone else. It joins the chain with that change.
Building it found a third copy nobody had counted, under a different name, and
two bugs in the gate's own first draft: a block-comment stripper that ate the
declarations it was meant to find (so every single-source assertion passed
while both files plainly defined the helper), and an exemption for lines
mentioning the helper, which hid a one-line definition that mentions it. Both
were caught by the rule that a gate must fail when poisoned.
