A harness, as one addable unit: the ports it implements plus the flags that
say which ones those are.
⚠️ THE COST, NAMED SO NOBODY IS SURPRISED BY IT: a wrong adapter literal
produces a TypeScript error against an INTERSECTION OF UNIONS, which reads
badly — it will list both arms of each union rather than say "you declared
harnessTesting and gave me no driver". That is why the conformance kit keeps
its per-flag messages: the TYPE is the gate, the KIT is the explanation.
A harness, as one addable unit: the ports it implements plus the flags that say which ones those are.
⚠️ THE COST, NAMED SO NOBODY IS SURPRISED BY IT: a wrong adapter literal produces a TypeScript error against an INTERSECTION OF UNIONS, which reads badly — it will list both arms of each union rather than say "you declared harnessTesting and gave me no driver". That is why the conformance kit keeps its per-flag messages: the TYPE is the gate, the KIT is the explanation.