From 346b1c5195bffc71ceaa9262453e3c189656400b Mon Sep 17 00:00:00 2001
From: godosa <godosa@godosa.eu>
Date: Tue, 6 Oct 2026 23:52:03 +0200
Subject: worldgen: initial public history

---
 tests/test_plates.py | 73 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 73 insertions(+)
 create mode 100644 tests/test_plates.py

(limited to 'tests/test_plates.py')

diff --git a/tests/test_plates.py b/tests/test_plates.py
new file mode 100644
index 0000000..9b71bb9
--- /dev/null
+++ b/tests/test_plates.py
@@ -0,0 +1,73 @@
+import unittest
+
+import numpy as np
+
+from mapgen import plates as PL
+from mapgen.pipeline import StageError
+from tests.helpers import make_ctx
+
+
+def two_plates(az_a, az_b, speed=5.0, kinds=("oceanic", "oceanic")):
+    return {"plate": [
+        {"id": "a", "seed": [0.0, -40.0], "kind": kinds[0], "motion": [az_a, speed]},
+        {"id": "b", "seed": [0.0, 40.0], "kind": kinds[1], "motion": [az_b, speed]},
+    ]}
+
+
+def ctx_for(tect, land=None, res=2):
+    ctx = make_ctx(res, tect=tect)
+    n = ctx.grid.n
+    ctx.data.update({"sk_land": np.zeros(n) if land is None else land, "m_land_hint": np.zeros(n)})
+    return ctx
+
+
+class PlatesTest(unittest.TestCase):
+    def test_convergent_then_divergent(self):
+        for az_a, az_b, want in ((90.0, 270.0, PL.CONV), (270.0, 90.0, PL.DIV)):
+            ctx = ctx_for(two_plates(az_a, az_b))
+            out = PL.run(ctx)
+            g = ctx.grid
+            near = (np.abs(g.lon) < 12) & (np.abs(g.lat) < 30) & (out["bnd_type"] > 0)
+            self.assertGreater(near.sum(), 3)
+            self.assertTrue(np.mean(out["bnd_type"][near] == want) > 0.8, (az_a, want))
+
+    def test_every_cell_assigned_and_seeds_own_cells(self):
+        ctx = ctx_for(two_plates(90.0, 270.0))
+        out = PL.run(ctx)
+        g = ctx.grid
+        self.assertEqual(set(np.unique(out["plate"])), {0, 1})
+        self.assertEqual(out["plate"][g.cell_index(0.0, -40.0)], 0)
+        self.assertEqual(out["plate"][g.cell_index(0.0, 40.0)], 1)
+
+    def test_continent_stays_on_its_plate(self):
+        tect = {"plate": [
+            {"id": "c", "seed": [0.0, 0.0], "kind": "continental", "motion": [0.0, 1.0]},
+            {"id": "o", "seed": [0.0, 60.0], "kind": "oceanic", "motion": [0.0, 1.0]},
+        ]}
+        ctx = make_ctx(2, tect=tect)
+        g = ctx.grid
+        land = ((np.abs(g.lat) < 20) & (np.abs(g.lon) < 40)).astype(float)
+        ctx.data.update({"sk_land": land, "m_land_hint": np.zeros(g.n)})
+        out = PL.run(ctx)
+        self.assertTrue(np.all(out["plate"][land > 0.5] == 0))
+
+    def test_duplicate_seed_cell_errors(self):
+        tect = two_plates(90.0, 270.0)
+        tect["plate"][1]["seed"] = [0.01, -40.01]
+        with self.assertRaisesRegex(StageError, "same cell"):
+            PL.run(ctx_for(tect))
+
+    def test_zero_speed_plate(self):
+        out = PL.run(ctx_for(two_plates(90.0, 270.0, speed=0.0)))
+        self.assertTrue(np.all(np.isfinite(out["vel"])))
+        self.assertTrue(np.allclose(out["vel"], 0.0))
+
+
+class MeanderTest(unittest.TestCase):
+    def test_boundaries_meander(self):
+        ctx = ctx_for(two_plates(90.0, 270.0, kinds=("continental", "continental")), res=4)
+        g = ctx.grid
+        ctx.data["sk_land"] = ((np.abs(g.lat) < 40) & (np.abs(g.lon) < 70)).astype(float)
+        out = PL.run(ctx)
+        b = (out["bnd_type"] > 0) & (np.abs(g.lat) < 35) & (np.abs(g.lon) < 40)
+        self.assertGreater(g.lon[b].std(), 3.0)
-- 
cgit