How to use the @xviz/io.XVIZ_FORMAT.JSON_STRING function in @xviz/io

TestXVIZSnapshotGLB = d;
  }
});
writer.writeMessage(0, TestXVIZSnapshot);

// Load the data in XVIZData and verify the format
const TestCases = [
  {
    data: TestXVIZSnapshot,
    description: 'XVIZ Object',
    format: XVIZ_FORMAT.OBJECT
  },
  {
    data: TestXVIZSnapshotString,
    description: 'XVIZ String',
    format: XVIZ_FORMAT.JSON_STRING
  },
  {
    data: `   ${TestXVIZSnapshotString}   `,
    description: 'XVIZ String with whitespace head and tail',
    format: XVIZ_FORMAT.JSON_STRING
  },
  {
    data: TestXVIZSnapshotBuffer,
    description: 'XVIZ String Buffer',
    format: XVIZ_FORMAT.JSON_BUFFER
  },
  {
    data: TestXVIZSnapshotGLB,
    description: 'XVIZ Binary Buffer',
    format: XVIZ_FORMAT.BINARY_GLB
  },

// Load the data in XVIZData and verify the format
const TestCases = [
  {
    data: TestXVIZSnapshot,
    description: 'XVIZ Object',
    format: XVIZ_FORMAT.OBJECT
  },
  {
    data: TestXVIZSnapshotString,
    description: 'XVIZ String',
    format: XVIZ_FORMAT.JSON_STRING
  },
  {
    data: `   ${TestXVIZSnapshotString}   `,
    description: 'XVIZ String with whitespace head and tail',
    format: XVIZ_FORMAT.JSON_STRING
  },
  {
    data: TestXVIZSnapshotBuffer,
    description: 'XVIZ String Buffer',
    format: XVIZ_FORMAT.JSON_BUFFER
  },
  {
    data: TestXVIZSnapshotGLB,
    description: 'XVIZ Binary Buffer',
    format: XVIZ_FORMAT.BINARY_GLB
  },
  {
    data: Buffer.from(TestXVIZSnapshotBuffer),
    description: 'XVIZ String NodeBuffer',
    format: XVIZ_FORMAT.JSON_BUFFER,
    nodeOnly: true

tape('XVIZFormatWriter#full matrix', t => {
  const dataSources = [
    TestXVIZSnapshot,
    TestXVIZSnapshotString,
    TestXVIZSnapshotBuffer,
    TestXVIZSnapshotGLB
  ];
  for (const source of dataSources) {
    const xvizObj = new XVIZData(source);

    for (const format of [
      XVIZ_FORMAT.BINARY_GLB,
      XVIZ_FORMAT.JSON_BUFFER,
      XVIZ_FORMAT.JSON_STRING
    ]) {
      const sink = new MemorySourceSink();

      t.comment(`-- TestCase ${xvizObj.format} to ${format}`);

      // Convert the data to the requested format
      // data is state_update and this will default to a message sequence of 0
      const formatWriter = new XVIZFormatWriter(sink, {format});
      formatWriter.writeMessage(0, xvizObj);

      // We don't really care about the key as each writer will have
      // different identifier, (eg: 1-frame.json vs 1.frame.glb)
      for (const [key, val] of sink.entries()) {
        // Cover Arrays, Strings, ArrayBuffers
        t.ok(val.byteLength || val.length, `${key} has formatted data`);

const testSessionMaker = (socket, req) => {
    const context = new XVIZSessionContext();
    const provider = new TestProvider(makeXVIZData(100, 110));
    const middleware = new XVIZServerMiddlewareStack();
    const stack = [
      new XVIZProviderRequestHandler(context, provider, middleware, {logger}),
      new XVIZWebsocketSender(context, socket, {format: XVIZ_FORMAT.JSON_STRING})
    ];
    middleware.set(stack);

    return new TestSession(socket, middleware);
  };