Function openSession

e2e/cloud/mcp-session-cap-eviction.test.ts:70–107

(
  mcpUrl: string,
  bearer: string,
  label: string,
  recordSession: (sessionId: string) => void,
)

 * orphaning a real session on the target isolate.
 */
const openSession = async (
  mcpUrl: string,
  bearer: string,
  label: string,
  recordSession: (sessionId: string) => void,
): Promise<string> => {
  const initialized = await postJson(mcpUrl, bearer, {
    jsonrpc: "2.0" as const,
    id: "initialize",
    method: "initialize",
    params: {
      protocolVersion: PROTOCOL_VERSION,
      capabilities: {},
      clientInfo: { name: `executor-e2e-cap-eviction-${label}`, version: "0.0.1" },
    },
  });
  const sessionId = initialized.headers.get("mcp-session-id");
  if (!sessionId) {
    // oxlint-disable-next-line executor/no-error-constructor -- boundary: e2e setup precondition.
    throw new Error(`openSession (${label}): no mcp-session-id header`);
  }
  // Recorded the moment the id exists — BEFORE the body read and status
  // assertion below, either of which can throw with the session already live
  // on the server. The cleanup finalizer needs the id on every one of those
  // paths, not just a fully successful return.
  recordSession(sessionId);
  await initialized.text();
  expect(initialized.status, `initialize (${label}) opens a session`).toBe(200);
  const notification = await postJson(
    mcpUrl,
    bearer,
    { jsonrpc: "2.0" as const, method: "notifications/initialized" },
    sessionId,
  );
  await notification.text();
  expect(notification.status, `(${label}) completes the handshake`).toBe(202);
  return sessionId;
};

const executeBody = (id: string, code: string) => ({
  jsonrpc: "2.0" as const,