continuum-backend/tests/edge_protocol.test.ts

import { describe, expect, it } from "bun:test";
import { Value } from "@sinclair/typebox/value";
import { EdgeClientMessageSchema, EdgeServerMessageSchema } from "@continuum/ts-types";

import currentCapture from "./fixtures/gateway_frames.json";
import legacyCapture from "./fixtures/gateway_frames_legacy_nulls.json";

/**
 * A contract test, not a unit test: it checks that what continuum-proxy
 * actually puts on the wire is what this backend's validator accepts.
 *
 * The fixtures are real captures from a live gateway talking to a real P1P and
 * H2C, not hand-written examples - which is the whole point. The two ends of
 * /ws/edge/v1 had silently drifted into completely different protocols
 * (different handshake, different telemetry shape, printer ids the gateway
 * could not know), and every hand-written example agreed with whichever side
 * wrote it. Re-capture with scripts/capture-gateway-frames.js when the protocol
 * changes, rather than editing these by hand.
 */

function check(schema: Parameters<typeof Value.Check>[0], value: unknown) {
  const ok = Value.Check(schema, value);
  if (!ok) {
    // Surface *why*, or a failure here is just "false !== true".
    const errors = [...Value.Errors(schema, value)].map(
      (e) => `${e.path || "/"}: ${e.message} (got ${JSON.stringify(e.value)})`,
    );
    throw new Error(`validation failed:\n  ${errors.join("\n  ")}`);
  }
}

describe("gateway -> backend frames", () => {
  for (const frame of currentCapture.frames) {
    it(`accepts a real '${frame.type}' frame`, () => {
      check(EdgeClientMessageSchema, frame);
    });
  }

  it("accepts the pre-fix capture, where empty fields were explicit nulls", () => {
    // Liberal reader: the gateway now omits these, but a serde-derived
    // producer emits null by default and one such field must not cost us a
    // whole farm's telemetry batch.
    for (const frame of legacyCapture.frames) {
      check(EdgeClientMessageSchema, frame);
    }
  });

  it("carries the live telemetry this was captured from", () => {
    const telemetry = currentCapture.frames.find((f) => f.type === "telemetry");
    expect(telemetry).toBeDefined();
    const printers = (telemetry as { printers: Array<{ printer_id: string }> }).printers;
    expect(printers.length).toBeGreaterThan(0);
    // Guards against a fixture that validates because it is empty.
    expect(printers.every((p) => typeof p.printer_id === "string" && p.printer_id.length > 0)).toBe(true);
  });

  it("rejects a telemetry batch whose printer has no id", () => {
    // printer_id and name are the only required fields; everything else is
    // genuinely unknowable for a printer that has only just connected.
    check(EdgeClientMessageSchema, { type: "telemetry", printers: [{ printer_id: "p1p", name: "P1P" }] });
    expect(Value.Check(EdgeClientMessageSchema, { type: "telemetry", printers: [{ name: "P1P" }] })).toBe(false);
  });

  it("rejects an unknown message type", () => {
    // The old protocol's handshake, which no gateway ever sent.
    expect(Value.Check(EdgeClientMessageSchema, { type: "auth", token: "x" })).toBe(false);
  });
});

describe("backend -> gateway frames", () => {
  // Exactly what src/routes/ws/edge.ts sends. If one of these stops
  // validating, the gateway's serde enum will have stopped accepting it too -
  // see the mirror of this test in continuum-proxy/tests/uplink_protocol.rs.
  const outbound = [
    { type: "hello_ack", session_id: "3f2b1c5e-0000-4000-8000-000000000000" },
    { type: "hello_error", message: "invalid edge token" },
    { type: "heartbeat_ack", seq: 7 },
    {
      type: "command",
      command_id: "9a7d2f10-0000-4000-8000-000000000000",
      printer_id: "p1p",
      command: { action: "set_fan_speed", percent: 40 },
    },
    {
      type: "command",
      command_id: "9a7d2f11-0000-4000-8000-000000000000",
      printer_id: "p1p",
      command: { action: "send_gcode_line", line: "M106 S0" },
    },
  ];

  for (const frame of outbound) {
    it(`emits a valid '${frame.type}' (${(frame as { command?: { action: string } }).command?.action ?? "no command"})`, () => {
      check(EdgeServerMessageSchema, frame);
    });
  }

  it("has no start-print command to send", () => {
    // Deliberate: the gateway can start an uploaded file, but that path has
    // never been run against real hardware. Delete this test when it has been,
    // and add the variant to the schema.
    expect(
      Value.Check(EdgeServerMessageSchema, {
        type: "command",
        command_id: "x",
        printer_id: "p1p",
        command: { action: "start_print", file_name: "plate_1.3mf" },
      }),
    ).toBe(false);
  });
});