Add scripted trainer battle foundation and native move AI

tests/trainer-fixture.ts

@@ -0,0 +1,30 @@
+import { CrystalAssets } from "../src/game/rom/assets";
+import { generatePartyMon } from "../src/game/party/pokemon";
+import { martFixtureWorld } from "./mart-fixture";
+
+// Test-only script on an already accessible clerk. The actual trainer party,
+// class attributes, moves and battle text are read from the local ROM.
+export function trainerFixtureWorld(assets: CrystalAssets, tail = [0x60, 0x33, 0x00, 0x01, 0x91], lose = false, winText = false) {
+  const clerk = assets.map("26:4").objects[0];
+  // Place the synthetic script in Joey's bank to test winlosstext's near pointer.
+  if (winText) clerk.script = 0x68 * 0x4000 + 0x3f00;
+  assets.reader.bytes.set([
+    0x64, ...(winText ? [0xa2, 0x58] : [0, 0]), 0, 0, // Joey beaten text or default
+    0x5e, 22, 1, // loadtrainer YOUNGSTER, JOEY1
+    ...(lose ? [0x1e, 3, 1] : []), // loadvar VAR_BATTLETYPE, BATTLETYPE_CANLOSE
+    0x5f, ...tail,
+  ], clerk.script);
+  const world = martFixtureWorld(assets);
+  const mon = generatePartyMon(assets.pokemon, {
+    species: 155, level: lose ? 2 : 50, item: 0, otId: world.playerId,
+    ot: "CHRIS", dvs: 0x823b, caughtData: 0,
+  });
+  mon.moves = [33, 0, 0, 0];
+  mon.pp = [35, 0, 0, 0];
+  if (lose) mon.hp = 1;
+  world.state.party = [mon];
+  world.state.pokedex.seen.add(155);
+  world.state.pokedex.caught.add(155);
+  return world;
+}
+