Web play: unit tests for reading a game setup and setting parameters

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

Author: hopshackle

WEBSERVER_PLAN.md

@@ -222,9 +222,12 @@ every GUI in the JVM. Instead the web session, which already drives the update t
 
 ## Testing
 
-- **Unit tests:** protocol and session logic (action validation, stale action rejection, lifecycle and stop). They run with
-  `-Dmaven.test.skip=false` and need a display: fine on Windows; under Xvfb in CI.
-- **End-to-end:** drive the real page with browser automation for each milestone.
+- **Unit tests** (`web.SessionConfigTest`, no display needed): reading a setup from a link, defaults, refusals with their
+  messages, setting parameters from strings, free-entry parameters. Run with
+  `mvn test -Dmaven.test.skip=false -Dtest=SessionConfigTest`. The existing tests of the packages touched (gui, LawnAndOrder,
+  Terraforming Mars, Colt Express, Love Letter, Pandemic, Poker): 141 tests including these, all passing.
+- **End to end**: a Java WebSocket client standing in for the page (tile reassembly, scripted mouse, wheel, actions, log),
+  Chrome for each stage's milestone, and the CI workflow for the Docker image.
 
 ## Risks
 

src/test/java/web/SessionConfigTest.java

@@ -0,0 +1,113 @@
+package web;
+
+import core.AbstractParameters;
+import games.GameType;
+import games.lawnandorder.LawnAndOrderParameters;
+import org.junit.Test;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import static org.junit.Assert.*;
+
+/**
+ * Reading a game setup from the play page's query string, and setting game parameters from the strings a form sends.
+ */
+public class SessionConfigTest {
+
+    private final GameCatalog games = new GameCatalog("LawnAndOrder,TicTacToe");
+    private final OpponentCatalog opponents = new OpponentCatalog("");
+
+    private static Map<String, List<String>> query(String... keyValues) {
+        Map<String, List<String>> q = new HashMap<>();
+        for (int i = 0; i < keyValues.length; i += 2)
+            q.put(keyValues[i], List.of(keyValues[i + 1]));
+        return q;
+    }
+
+    private SessionConfig read(String... keyValues) {
+        return SessionConfig.fromQuery(query(keyValues), games, opponents);
+    }
+
+    @Test
+    public void aFullSetupIsRead() {
+        SessionConfig c = read("game", "LawnAndOrder", "players", "4", "seat", "2",
+                "opponents", "mcts-100,random,you,osla", "seed", "42", "pause", "0", "p.handSize", "6", "insight", "1");
+        assertEquals(GameType.LawnAndOrder, c.game());
+        assertEquals(4, c.nPlayers());
+        assertEquals(2, c.seat());
+        assertEquals(List.of("mcts-100", "random", "you", "osla"), c.opponents());
+        assertEquals(42, c.seed());
+        assertEquals(0, c.turnPause());
+        assertEquals(Map.of("handSize", "6"), c.params());
+        assertTrue(c.insight());
+    }
+
+    @Test
+    public void defaultsFillTheGaps() {
+        SessionConfig c = read();
+        assertEquals(GameType.LawnAndOrder, c.game());   // the first game offered
+        assertEquals(3, c.nPlayers());
+        assertEquals(0, c.seat());
+        assertEquals(List.of("you", OpponentCatalog.DEFAULT, OpponentCatalog.DEFAULT), c.opponents());
+        assertEquals(-1, c.seed());
+        assertEquals(SessionConfig.DEFAULT_TURN_PAUSE, c.turnPause());
+        assertTrue(c.params().isEmpty());
+        assertFalse(c.insight());
+    }
+
+    @Test
+    public void theDefaultPlayerCountFitsTheGame() {
+        assertEquals(2, read("game", "TicTacToe").nPlayers());
+    }
+
+    @Test
+    public void theBrowserSeatIsAlwaysYou() {
+        SessionConfig c = read("players", "2", "seat", "1", "opponents", "random,random");
+        assertEquals(List.of("random", "you"), c.opponents());
+    }
+
+    @Test
+    public void badSetupsAreRefused() {
+        assertRefused("Unknown game", "game", "Chess");   // not offered
+        assertRefused("takes 2 to 6 players", "players", "9");
+        assertRefused("seat must be between", "players", "3", "seat", "3");
+        assertRefused("Unknown opponent", "opponents", "you,nobody");
+        assertRefused("Unknown parameter", "p.noSuchThing", "1");
+        assertRefused("Bad value for handSize", "p.handSize", "lots");
+        assertRefused("Not a whole number for seed", "seed", "abc");
+        assertRefused("pause must be between", "pause", "-5");
+    }
+
+    private void assertRefused(String messagePart, String... keyValues) {
+        try {
+            read(keyValues);
+            fail("Expected the setup to be refused: " + messagePart);
+        } catch (IllegalArgumentException e) {
+            assertTrue(e.getMessage() + " should mention: " + messagePart, e.getMessage().contains(messagePart));
+        }
+    }
+
+    @Test
+    public void parametersAreSetFromStrings() {
+        AbstractParameters params = GameType.LawnAndOrder.createParameters(1);
+        GameCatalog.apply(params, Map.of("handSize", "7", "maxRounds", "12"));
+        LawnAndOrderParameters p = (LawnAndOrderParameters) params;
+        assertEquals(7, p.handSize);
+        assertEquals(7, p.getParameterValue("handSize"));
+        assertEquals(12, p.getParameterValue("maxRounds"));
+    }
+
+    @Test
+    public void parametersWithoutAListOfSettingsAreFreeEntry() {
+        var described = GameCatalog.describeParameters(GameType.LawnAndOrder);
+        for (var e : described) {
+            var p = e.getAsJsonObject();
+            if (p.get("name").getAsString().equals("maxRounds"))
+                assertEquals(0, p.getAsJsonArray("values").size());
+            if (p.get("name").getAsString().equals("handSize"))
+                assertTrue(p.getAsJsonArray("values").size() > 1);
+        }
+    }
+}