Merge #1843 into #1847: share LocatorBarClient's respawn command and the harness scaffold

Both add the same respawn command to LocatorBarClient; this branch now
builds on #1843's, and test_pearl_death_parity.py runs through
locator.one_player.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

crates/horizon-client/src/game/agent.rs

@@ -1598,8 +1598,12 @@ impl Game<'_> {
                 if self.screen != Screen::Dead {
                     return Err("respawn needs the death screen".into());
                 }
-                let label =
-                    horizon_client::text::Text::translate("deathScreen.respawn", &[]).plain();
+                let key = if self.level.hardcore {
+                    "deathScreen.spectate"
+                } else {
+                    "deathScreen.respawn"
+                };
+                let label = horizon_client::text::Text::translate(key, &[]).plain();
                 let w = widgets::find(&widgets::last(), &label)?;
                 if !w.enabled {
                     // DeathScreen enables its buttons after 20 ticks.

crates/horizon-client/src/game/lan_actions.rs

@@ -1649,6 +1649,11 @@ impl Game<'_> {
             border: &self.border,
         };
         host.hub.respawn(i, spawn, &ctx);
+        // ServerGamePacketListenerImpl.handleClientCommand: a hardcore world's
+        // respawned player only watches.
+        if self.level.hardcore {
+            host.hub.set_game_mode(conn, SPECTATOR);
+        }
         if let Some(config) = elsewhere {
             self.respawn_trip(conn, config);
         }

crates/horizon-client/src/game/screens.rs

@@ -2,6 +2,7 @@
 use super::{Game, Screen};
 use horizon_client::{
     Result,
+    command::args::GameMode,
     hud::{HudBatch, rgba},
     text::{self, Text},
     ui,
@@ -81,9 +82,15 @@ fn pause_icons(w: f32, h: f32) -> [(f32, f32, &'static str); 4] {
         (x0 + 72.0, y, "gui/sprites/pause_menu/player_reporting"),
     ]
 }
-fn death_buttons(w: f32, h: f32) -> [(f32, f32, &'static str, u8); 2] {
+/// DeathScreen.init: a hardcore player can only spectate.
+fn death_buttons(w: f32, h: f32, hardcore: bool) -> [(f32, f32, &'static str, u8); 2] {
+    let respawn = if hardcore {
+        "deathScreen.spectate"
+    } else {
+        "deathScreen.respawn"
+    };
     [
-        (w / 2.0 - 100.0, h / 4.0 + 72.0, "deathScreen.respawn", 0),
+        (w / 2.0 - 100.0, h / 4.0 + 72.0, respawn, 0),
         (
             w / 2.0 - 100.0,
             h / 4.0 + 96.0,
@@ -223,7 +230,12 @@ impl Game<'_> {
                 ),
             );
         }
-        let title = Text::translate("deathScreen.title", &[]);
+        let title = if self.level.hardcore {
+            "deathScreen.title.hardcore"
+        } else {
+            "deathScreen.title"
+        };
+        let title = Text::translate(title, &[]);
         let tw = atlas.font.width_text(&title);
         ui::text_scaled(
             batch,
@@ -258,7 +270,7 @@ impl Game<'_> {
             .ui
             .died_at
             .is_none_or(|t| t.elapsed().as_millis() >= 1000);
-        for (x, y, key, _) in death_buttons(w, h) {
+        for (x, y, key, _) in death_buttons(w, h, self.level.hardcore) {
             let hover = active && ui::hovered(self.cursor, x, y, 200.0, 20.0);
             ui::button(
                 batch,
@@ -286,7 +298,7 @@ impl Game<'_> {
             .as_ref()
             .map_or([1, 1], |r| [r.config.width, r.config.height]);
         let b = HudBatch::new(size);
-        let hit = death_buttons(b.width, b.height)
+        let hit = death_buttons(b.width, b.height, self.level.hardcore)
             .into_iter()
             .find(|d| ui::hovered(self.cursor, d.0, d.1, 200.0, 20.0))
             .map(|d| d.3);
@@ -330,6 +342,11 @@ impl Game<'_> {
             Some(1) => self.close_world()?,
             _ => {}
         }
+        // ServerGamePacketListenerImpl.handleClientCommand: a hardcore world's
+        // respawned player only watches.
+        if hit == Some(0) && self.remote.is_none() && self.level.hardcore {
+            self.set_mode(GameMode::Spectator);
+        }
         if hit.is_some() {
             self.audio.play_button_click();
         }

tools/test_hardcore_respawn_parity.py

@@ -0,0 +1,49 @@
+#!/usr/bin/env python3
+"""Respawning in a hardcore world on a dedicated server, against vanilla's, seen by a vanilla client.
+
+A vanilla dedicated server and Horizon's (`horizon-client --dedicated --nogui`) each serve a copy of one hardcore
+flat world vanilla generated first, with Alice an operator in survival. LocatorBarClient (a player made of
+vanilla's protocol code) joins, runs /kill on itself and presses the death screen's button
+(ServerboundClientCommandPacket PERFORM_RESPAWN). Vanilla's ServerGamePacketListenerImpl.handleClientCommand
+respawns the player, then makes it a spectator because the server is hardcore. The game mode changes and respawns
+Alice is sent in the death and respawn steps are compared exactly.
+"""
+import sys
+
+try:
+    from . import test_locator_bar_parity as locator
+except ImportError:
+    import test_locator_bar_parity as locator
+
+NAME = 'hardcore-respawn-parity'
+# server_dir and generate_world write these server.properties.
+locator.PROPERTIES = dict(locator.PROPERTIES, hardcore='true', gamemode='survival')
+SCRIPT = [
+    ('death', ['cmd Alice kill @s']),
+    ('respawn', ['respawn Alice']),
+]
+
+
+def shown(lines):
+    """Alice's game mode changes and respawns in the death and respawn steps."""
+    return [line for line in lines if len(parts := line.split(' ', 3)) >= 3
+            and parts[1] in ('step=death', 'step=respawn') and parts[2] in ('gamemode', 'respawn')]
+
+
+def check(vanilla, _):
+    if 'Alice step=respawn gamemode 3' not in vanilla:
+        return 'vanilla did not make the respawned player a spectator'
+    return None
+
+
+def main():
+    lines = locator.one_player(NAME, SCRIPT, shown, check, 'A player dying and respawning in a hardcore world on a '
+                               'dedicated server: the respawn and the game mode it is sent (spectator).')
+    print(f'hardcore respawn: {len(lines)} lines identical')
+
+
+if __name__ == '__main__':
+    try:
+        main()
+    except AssertionError as error:
+        sys.exit(f'{NAME}: {error}')

tools/test_locator_bar_parity.py

@@ -205,12 +205,13 @@ def run_side(label, server_command, client_command, build, world):
     return out.read_text(encoding='utf-8').splitlines()
 
 
-def main():
+def sides(name):
+    """The vanilla and Horizon dedicated servers and the LocatorBarClient that joins them, built for harness
+    `name`: (lock, build directory, vanilla server, Horizon server, client) commands."""
     lock, jars, libraries = base.verify_artifacts()
-    build = lab.LOCAL / NAME
+    build = lab.LOCAL / name
     build.mkdir(parents=True, exist_ok=True)
-    report = build / 'report.json'
-    report.unlink(missing_ok=True)
+    (build / 'report.json').unlink(missing_ok=True)
     oracle = lab.ROOT / 'mods/horizon/src/test/java/dev/horizonlab/parity/LocatorBarClient.java'
     classes = build / 'classes'
     shutil.rmtree(classes, ignore_errors=True)
@@ -228,7 +229,74 @@ def main():
     vanilla_server = ['java', '-Xmx2g', '-Duser.timezone=UTC', '-cp', dependencies, 'net.minecraft.server.Main', 'nogui']
     horizon_server = [binary, '--resources', lab.LOCAL / 'horizon-client/26.3', '--dedicated', '--nogui']
     client = ['java', '-Xmx1g', '-cp', str(classes) + os.pathsep + dependencies, 'dev.horizonlab.parity.LocatorBarClient']
+    return lock, build, vanilla_server, horizon_server, client
 
+
+def one_player(name, script, shown, check, scope, step_seconds=4.0):
+    """A harness of one player, Alice: on each server she joins, then runs `script`, a list of (step, client
+    actions) `step_seconds` apart. The lines `shown(transcript)` keeps must match vanilla's exactly, and
+    `check(vanilla's shown lines, vanilla's transcript)` returns why vanilla's run is no proof (the script did
+    not run), or None."""
+    lock, build, vanilla_server, horizon_server, client = sides(name)
+
+    def run(label, server_command, world):
+        directory = build / label
+        port = server_dir(directory, world)
+        out = build / f'{label}.txt'
+        out.unlink(missing_ok=True)
+        server = Server(server_command, directory, label)
+        try:
+            server.wait_for(r'Done \(')
+            with (build / f'{label}-client.log').open('w') as log:
+                process = subprocess.Popen([*map(str, client), '127.0.0.1', str(port), str(out)], cwd=lab.ROOT,
+                                           stdin=subprocess.PIPE, stdout=log, stderr=subprocess.STDOUT, text=True)
+
+                def tell(line):
+                    process.stdin.write(line + '\n')
+                    process.stdin.flush()
+                try:
+                    for line in ['players on', 'state on', 'step joins', 'join Alice']:
+                        tell(line)
+                    server.wait_for(r'Alice joined the game', timeout=120)
+                    time.sleep(step_seconds)
+                    for step, actions in script:
+                        tell(f'step {step}')
+                        for action in actions:
+                            tell(action)
+                        time.sleep(step_seconds)
+                    tell('end')
+                    process.wait(timeout=60)
+                finally:
+                    if process.poll() is None:
+                        process.kill()
+        finally:
+            server.stop()
+        if not out.exists():
+            raise AssertionError(f'{label}: the client wrote no transcript (see {build}/{label}-client.log)')
+        return out.read_text(encoding='utf-8').splitlines()
+
+    world = generate_world(vanilla_server, build)
+    vanilla_all = run('vanilla', vanilla_server, world)
+    horizon_all = run('horizon', horizon_server, world)
+    errors = [l for l in vanilla_all + horizon_all if ' error ' in f' {l} ' or 'disconnected' in l]
+    vanilla, horizon = shown(vanilla_all), shown(horizon_all)
+    if errors or vanilla != horizon:
+        import difflib
+        diff = '\n'.join(difflib.unified_diff(vanilla, horizon, 'vanilla', 'horizon', n=1, lineterm=''))
+        raise AssertionError(f'{len(errors)} errors, transcripts differ (see {build}/vanilla.txt and horizon.txt):\n'
+                             + '\n'.join(errors[:10]) + '\n' + diff[:6000])
+    if (why := check(vanilla, vanilla_all)) is not None:
+        raise AssertionError(f'{why}: the script did not run (see {build})')
+    lab.write_json(build / 'report.json', dict(
+        schema=1, minecraft=lock['minecraft']['version'], platform=platform.platform(),
+        java=subprocess.check_output(['java', '--version'], text=True).splitlines()[0],
+        lines=len(vanilla), output_sha256=lab.digest(build / 'horizon.txt', 'sha256'), scope=scope))
+    return vanilla
+
+
+def main():
+    lock, build, vanilla_server, horizon_server, client = sides(NAME)
+    report = build / 'report.json'
     world = generate_world(vanilla_server, build)
     vanilla = run_side('vanilla', vanilla_server, client, build, world)
     horizon = run_side('horizon', horizon_server, client, build, world)

tools/test_pearl_death_parity.py

@@ -9,31 +9,16 @@ ender_pearls_vanish_on_death true: ThrownEnderpearl.tick discards a dead owner's
 never teleported. The teleports, game mode changes and respawns Alice is sent from the throw on are compared
 exactly.
 """
-import json
-import os
-from pathlib import Path
-import platform
-import shutil
-import subprocess
 import sys
-import time
 
 try:
-    from . import lab, test_rust_parity as base, test_locator_bar_parity as locator
-    from .test_dedicated_server_parity import Server
+    from . import test_locator_bar_parity as locator
 except ImportError:
-    import lab
-    import test_rust_parity as base
     import test_locator_bar_parity as locator
-    from test_dedicated_server_parity import Server
 
 NAME = 'pearl-death-parity'
 # server_dir and generate_world write these server.properties.
 locator.PROPERTIES = dict(locator.PROPERTIES, gamemode='survival')
-STEP_SECONDS = 4.0
-SHOWN = ('teleport', 'gamemode', 'respawn')
-
-
 SCRIPT = [
     ('setup', ['cmd Alice gamerule ender_pearls_vanish_on_death true', 'cmd Alice give @s minecraft:ender_pearl']),
     # Straight up: it comes down about four seconds later, near where it was thrown.
@@ -43,96 +28,25 @@ SCRIPT = [
 ]
 
 
-def run_side(label, server_command, client_command, build, world):
-    directory = build / label
-    port = locator.server_dir(directory, world)
-    out = build / f'{label}.txt'
-    out.unlink(missing_ok=True)
-    server = Server(server_command, directory, label)
-    try:
-        server.wait_for(r'Done \(')
-        with (build / f'{label}-client.log').open('w') as log:
-            client = subprocess.Popen([*map(str, client_command), '127.0.0.1', str(port), str(out)],
-                                      cwd=lab.ROOT, stdin=subprocess.PIPE, stdout=log, stderr=subprocess.STDOUT,
-                                      text=True)
-
-            def tell(line):
-                client.stdin.write(line + '\n')
-                client.stdin.flush()
-            try:
-                tell('players on')
-                tell('state on')
-                tell('step joins')
-                tell('join Alice')
-                server.wait_for(r'Alice joined the game', timeout=120)
-                time.sleep(STEP_SECONDS)
-                for step, actions in SCRIPT:
-                    tell(f'step {step}')
-                    for action in actions:
-                        tell(action)
-                    time.sleep(STEP_SECONDS)
-                tell('end')
-                client.wait(timeout=60)
-            finally:
-                if client.poll() is None:
-                    client.kill()
-    finally:
-        server.stop()
-    if not out.exists():
-        raise AssertionError(f'{label}: the client wrote no transcript (see {build}/{label}-client.log)')
-    return out.read_text(encoding='utf-8').splitlines()
-
-
 def shown(lines):
-    """Alice's teleports, game mode changes and respawns from the throws on."""
+    """Alice's teleports, game mode changes and respawns from the throw on."""
     steps = {f'step={step}' for step, _ in SCRIPT if step != 'setup'}
     return [line for line in lines if len(parts := line.split(' ', 3)) >= 3 and parts[1] in steps
-            and parts[2] in SHOWN]
+            and parts[2] in ('teleport', 'gamemode', 'respawn')]
+
+
+def check(vanilla, vanilla_all):
+    killed = any(l.startswith('Alice step=throw killed') for l in vanilla_all)
+    if not killed or 'Alice step=respawn respawn minecraft:overworld' not in vanilla:
+        return 'vanilla did not kill and respawn Alice'
+    return None
 
 
 def main():
-    lock, jars, libraries = base.verify_artifacts()
-    build = lab.LOCAL / NAME
-    build.mkdir(parents=True, exist_ok=True)
-    report = build / 'report.json'
-    report.unlink(missing_ok=True)
-    oracle = lab.ROOT / 'mods/horizon/src/test/java/dev/horizonlab/parity/LocatorBarClient.java'
-    classes = build / 'classes'
-    shutil.rmtree(classes, ignore_errors=True)
-    classes.mkdir()
-    dependencies = os.pathsep.join(map(str, [jars['server'], *libraries]))
-    subprocess.run(['javac', '--release', str(lock['minecraft']['java_major']), '-proc:none', '-nowarn', '-sourcepath',
-                    lab.ROOT / 'mods/horizon/src/test/java', '-cp', dependencies, '-d', classes, oracle],
-                   cwd=lab.ROOT, check=True, capture_output=True)
-    subprocess.run(['cargo', 'build', '--release', '-p', 'horizon-client', '--bin', 'horizon-client'], cwd=lab.ROOT,
-                   check=True, capture_output=True)
-    metadata = json.loads(subprocess.check_output(['cargo', 'metadata', '--no-deps', '--format-version', '1'],
-                                                  cwd=lab.ROOT, text=True))
-    binary = Path(metadata['target_directory']) / 'release' / ('horizon-client.exe' if os.name == 'nt' else 'horizon-client')
-    vanilla_server = ['java', '-Xmx2g', '-Duser.timezone=UTC', '-cp', dependencies, 'net.minecraft.server.Main', 'nogui']
-    horizon_server = [binary, '--resources', lab.LOCAL / 'horizon-client/26.3', '--dedicated', '--nogui']
-    client = ['java', '-Xmx1g', '-cp', str(classes) + os.pathsep + dependencies, 'dev.horizonlab.parity.LocatorBarClient']
-
-    world = locator.generate_world(vanilla_server, build)
-    vanilla_all = run_side('vanilla', vanilla_server, client, build, world)
-    horizon_all = run_side('horizon', horizon_server, client, build, world)
-    errors = [l for l in vanilla_all + horizon_all if ' error ' in f' {l} ' or 'disconnected' in l]
-    vanilla, horizon = shown(vanilla_all), shown(horizon_all)
-    if errors or vanilla != horizon:
-        import difflib
-        diff = '\n'.join(difflib.unified_diff(vanilla, horizon, 'vanilla', 'horizon', n=1, lineterm=''))
-        raise AssertionError(f'{len(errors)} errors, transcripts differ (see {build}/vanilla.txt and horizon.txt):\n'
-                             + '\n'.join(errors[:10]) + '\n' + diff[:6000])
-    killed = any(l.startswith('Alice step=throw killed') for l in vanilla_all)
-    if not killed or 'Alice step=respawn respawn minecraft:overworld' not in vanilla:
-        raise AssertionError(f'vanilla did not kill and respawn Alice: the script did not run (see {build})')
-    lab.write_json(report, dict(
-        schema=1, minecraft=lock['minecraft']['version'], platform=platform.platform(),
-        java=subprocess.check_output(['java', '--version'], text=True).splitlines()[0],
-        lines=len(vanilla), output_sha256=lab.digest(build / 'horizon.txt', 'sha256'),
-        scope='An ender pearl in flight when its thrower dies and respawns on a dedicated server, with '
-              'ender_pearls_vanish_on_death true: the pearl vanishes and never teleports the player.'))
-    print(f'pearl death: {len(vanilla)} lines identical')
+    lines = locator.one_player(NAME, SCRIPT, shown, check, 'An ender pearl in flight when its thrower dies and '
+                               'respawns on a dedicated server, with ender_pearls_vanish_on_death true: the pearl '
+                               'vanishes and never teleports the player.')
+    print(f'pearl death: {len(lines)} lines identical')
 
 
 if __name__ == '__main__':