reset ingame test worlds to noon in clear weather between scripts

tests/ingame/README.md

@@ -43,7 +43,8 @@ The runner (`tools/ingame-test`):
    (17 for 1.20.x, 21 for 1.21.x, 25 for 26.x): `JAVA_HOME_<major>` if set,
    else `JAVA_HOME`, else `java` on `PATH`. A newer Java runs older servers.
 3. Runs a debug client per script, joining as that version, then resets the
-   player for the next one.
+   player for the next one, and the world to noon in clear weather with time
+   ticking.
 
 With `--jobs N`, N workers per version each start their own server and world
 under `target/ingame/workers/<version>/<n>/` and take scripts from a shared

tools/ingame-test/src/main.rs

@@ -626,10 +626,8 @@ impl Server {
         // out of the reset's reach; keep the area around spawn loaded.
         server.command("forceload add -48 -48 47 47");
         // Mobs spawning at night attack and push the test player mid-script.
-        // 26.x renamed the rule; each version rejects the name it lacks.
-        for rule in ["spawn_mobs", "doMobSpawning"] {
-            server.command(&format!("gamerule {rule} false"));
-        }
+        server.gamerule(["spawn_mobs", "doMobSpawning"], false);
+        server.reset_world();
         Ok(server)
     }
 
@@ -656,6 +654,14 @@ impl Server {
         let _ = writeln!(self.stdin, "{command}");
     }
 
+    /// Sets a game rule by its 26.x and older names; each version rejects
+    /// the name it lacks.
+    fn gamerule(&mut self, names: [&str; 2], value: bool) {
+        for name in names {
+            self.command(&format!("gamerule {name} {value}"));
+        }
+    }
+
     /// Clears what a script left behind. Once the player has left and the
     /// world is saved, their data is deleted so the next join starts fresh.
     fn reset_player(&mut self) -> Result<(), String> {
@@ -678,9 +684,18 @@ impl Server {
         for _ in 0..2 {
             self.command("kill @e[type=!player]");
         }
+        self.reset_world();
         Ok(())
     }
 
+    /// Noon, clear and ticking, so a script that doesn't set the time or
+    /// weather sees the same sky whether it runs first or after others.
+    fn reset_world(&mut self) {
+        self.gamerule(["advance_time", "doDaylightCycle"], true);
+        self.command("time set 6000");
+        self.command("weather clear");
+    }
+
     /// Blocks until the server exits (Ctrl+C or `stop`).
     fn wait(&mut self) {
         let _ = self.child.wait();