Improve netcode and simplify (#4)

- Simplify the logic wherever possible to remove overengineering and simplify the netcode
- Actually improve the netcode
- The new lines are mainly the package locks and tests

Reviewed-on: https://home.schmelczer.dev/git/andras/decla-red/pulls/4

test/client-send-cadence.test.ts

@@ -0,0 +1,101 @@
+import { describe, it, expect } from 'vitest';
+import { createRequire } from 'node:module';
+
+import { CommandSocket } from '../frontend/src/scripts/commands/command-socket';
+import { setFrameTimeMs } from '../frontend/src/scripts/helper/prediction/local-character-predictor';
+
+const require = createRequire(import.meta.url);
+const shared = require('../shared/lib/main.js');
+const { vec2 } = require('../shared/node_modules/gl-matrix');
+const { settings, MoveActionCommand, ClientHeartbeatCommand } = shared;
+
+const drive = (
+  frameRate: number,
+  seconds: number,
+  onFrame?: (socket: any) => void,
+  connected = true,
+) => {
+  const batches: Array<string> = [];
+  const socket = {
+    connected,
+    emit: (_event: string, payload: string) => batches.push(payload),
+  };
+  const commandSocket = new CommandSocket(socket as never);
+
+  const frames = Math.round(frameRate * seconds);
+  for (let f = 0; f < frames; f++) {
+    setFrameTimeMs((f * 1000) / frameRate);
+    onFrame?.(commandSocket);
+    commandSocket.sendQueuedCommands();
+  }
+  return batches;
+};
+
+describe('client send cadence', () => {
+  it('is paced by the clock, not by the frame rate', () => {
+    const seconds = 3;
+    const expected = seconds / settings.clientSendInterval;
+
+    for (const frameRate of [60, 144, 240]) {
+      const batches = drive(frameRate, seconds);
+      expect(batches.length).toBeLessThanOrEqual(expected * 1.1);
+      expect(batches.length).toBeGreaterThanOrEqual(expected * 0.85);
+    }
+  });
+
+  it('stays under the server allowance even at an absurd frame rate', () => {
+    const seconds = 5;
+    const batches = drive(1000, seconds);
+
+    expect(batches.length / seconds).toBeLessThan(settings.maxInboundMessagesPerSecond);
+  });
+
+  it('still flushes real input on the frame it happens', () => {
+    let sentOn = -1;
+    const batches = drive(144, 0.1, (commandSocket) => {
+      if (sentOn === -1) {
+        commandSocket.queue(new MoveActionCommand(vec2.fromValues(1, 0), 0));
+        sentOn = 0;
+      }
+    });
+
+    expect(batches.length).toBeGreaterThan(0);
+    expect(batches[0]).toContain('MoveActionCommand');
+  });
+
+  it('closes every batch with a heartbeat, so a held key keeps the ack moving', () => {
+    const batches = drive(60, 1);
+
+    expect(batches.length).toBeGreaterThan(0);
+    expect(batches.every((b) => b.includes(ClientHeartbeatCommand.name))).toBe(true);
+  });
+
+  it('sends nothing at all while the transport is down', () => {
+    const batches = drive(
+      60,
+      30,
+      (commandSocket) =>
+        commandSocket.queue(new MoveActionCommand(vec2.fromValues(1, 0), 0)),
+      false,
+    );
+
+    expect(batches).toHaveLength(0);
+  });
+
+  it('discards commands from the previous connection before the next join', () => {
+    const batches: Array<string> = [];
+    const socket = new CommandSocket({
+      connected: true,
+      emit: (_event: string, payload: string) => batches.push(payload),
+    } as never);
+    setFrameTimeMs(1000);
+    socket.sendQueuedCommands();
+    socket.queue(new MoveActionCommand(vec2.fromValues(1, 0), 1000));
+    socket.reset();
+    socket.sendQueuedCommands();
+
+    expect(batches).toHaveLength(2);
+    expect(batches[1]).toContain(ClientHeartbeatCommand.name);
+    expect(batches[1]).not.toContain(MoveActionCommand.name);
+  });
+});