Add retain keyword to endTurn

src/state.test.js

@@ -353,6 +353,22 @@ describe("endTurn - ethereal", () => {
   });
 });
 
+describe("endTurn - retain", () => {
+  test("retained cards stay in hand at end of turn", () => {
+    let state = createCombatState("ironclad", "jaw_worm");
+    const player = {
+      ...state.player,
+      hand: ["strike_r", "equilibrium", "defend_r"],
+    };
+    state = { ...state, player, players: [player] };
+    const next = endTurn(state);
+    expect(next.player.hand).toContain("equilibrium");
+    expect(next.player.discardPile).toContain("strike_r");
+    expect(next.player.discardPile).toContain("defend_r");
+    expect(next.player.hand).toHaveLength(1);
+  });
+});
+
 describe("playCard - unplayable", () => {
   test("unplayable card cannot be played", () => {
     let state = createCombatState("ironclad", "jaw_worm");