test(simulation): lock standalone-HQ-as-ordinary-settlement-row invariant (T-1074)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-07-16 10:29:17 +02:00
parent 62bbf57009
commit 314894d080
2 changed files with 114 additions and 0 deletions
@@ -828,6 +828,76 @@ mod tests {
        assert!(p2.synthetic);
    }

+    /// D-242: "hubs are the significant cities, standalone HQs are typically
+    /// minor nodes." `match_cities` has no concept of "corp-originated"
+    /// settlement — a Standalone-HQ CityRecord competes on population/class
+    /// exactly like an ordinary pooled city, so a modest-population HQ must
+    /// NOT out-rank a genuinely major city for the best attractor, and a
+    /// major HQ (large population, or NameLocked) DOES win Tier A on the same
+    /// terms any other settlement would. Both directions verified here.
+    #[test]
+    fn standalone_hq_settlement_competes_on_equal_terms_with_pooled_cities() {
+        let major_city = make_city(1, SettlementClass::PopulationBudget, 5_000_000);
+        // A "minor node" Standalone HQ (D-242's own framing) — modest
+        // population, ordinary PopulationBudget class, nothing marking it as
+        // corp-originated (mirrors populate_standalone_hq_settlements' output
+        // shape: an atlas_city_names row with no corp_id, same as any city).
+        let minor_hq = make_city(2, SettlementClass::PopulationBudget, 80_000);
+        let cities = vec![major_city, minor_hq];
+        let attractors = vec![
+            make_attractor(5, 5, AttractorType::RiverMouth, 95), // best
+            make_attractor(10, 10, AttractorType::ValleyFloor, 30), // worst
+        ];
+        let matrix = uniform_matrix();
+        let placements = match_cities(
+            &cities,
+            &attractors,
+            &matrix,
+            None,
+            512,
+            256,
+            &TerritorialStatus::FrontierUnclaimed,
+            SeedChain::root(42),
+        );
+        let major = placements.iter().find(|p| p.city_id == 1).unwrap();
+        let minor = placements.iter().find(|p| p.city_id == 2).unwrap();
+        assert_eq!(
+            major.position,
+            (5, 5),
+            "the major city (5M pop) must win the best attractor over an 80k-pop HQ"
+        );
+        assert_eq!(
+            minor.position,
+            (10, 10),
+            "the minor HQ gets whatever's left — no special corp-origin priority"
+        );
+
+        // Flip it: a NameLocked HQ (the T-1075 hero-pin path — e.g. "The Gate
+        // Corporation" in the real data) DOES win Tier A, on the same
+        // NameLocked-priority terms as any hero-pinned city (tier_a_gets_priority,
+        // above) — population size never mattered for NameLocked, corp-origin
+        // doesn't add or subtract anything either.
+        let hero_hq = make_city(3, SettlementClass::NameLocked, 200_000);
+        let ordinary_city = make_city(4, SettlementClass::PopulationBudget, 3_000_000);
+        let cities2 = vec![hero_hq, ordinary_city];
+        let placements2 = match_cities(
+            &cities2,
+            &attractors,
+            &matrix,
+            None,
+            512,
+            256,
+            &TerritorialStatus::FrontierUnclaimed,
+            SeedChain::root(42),
+        );
+        let hero = placements2.iter().find(|p| p.city_id == 3).unwrap();
+        assert_eq!(
+            hero.position,
+            (5, 5),
+            "NameLocked HQ wins Tier A over a larger ordinary city — same rule as any NameLocked settlement"
+        );
+    }
+
    #[test]
    fn all_cities_placed() {
        let cities: Vec<CityRecord> = (1..=5)