Function createHttpAdapter

ui/src/lib/adapter.ts:307–466

(options: HttpAdapterOptions = {})

 * network-level `TypeError` says nothing a reader can act on.
 */
export function createHttpAdapter(options: HttpAdapterOptions = {}): GraphAdapter {
  const base = options.baseUrl ?? '';
  const doFetch = options.fetch ?? ((...args: Parameters<typeof globalThis.fetch>) =>
    globalThis.fetch(...args));

  async function call<T>(path: string, init: RequestInit, signal?: AbortSignal): Promise<T> {
    let response: Response;
    try {
      response = await doFetch(`${base}${path}`, { ...init, signal });
    } catch (cause) {
      if (signal?.aborted) throw cause;
      throw new ApiFailure(
        0,
        'unreachable',
        'The codegraph ui server is not answering.',
        'It may have been stopped — restart it with `codegraph ui` and reload this page.'
      );
    }

    const body = (await response.json().catch(() => null)) as unknown;
    if (!response.ok) {
      const failure = (body as ApiErrorBody | null) ?? {};
      throw new ApiFailure(
        response.status,
        failure.code ?? 'error',
        failure.error ?? `The server answered ${response.status}.`,
        failure.hint ?? null
      );
    }
    return body as T;
  }

  function getJson<T>(path: string, signal?: AbortSignal): Promise<T> {
    return call<T>(path, { headers: { accept: 'application/json' } }, signal);
  }

  /** A write: the marker header, and a JSON body when there is one to send. */
  function write<T>(path: string, method: string, body?: unknown, signal?: AbortSignal): Promise<T> {
    const headers: Record<string, string> = {
      accept: 'application/json',
      [WRITE_HEADER]: '1',
    };
    if (body !== undefined) headers['content-type'] = 'application/json';
    return call<T>(
      path,
      { method, headers, ...(body === undefined ? {} : { body: JSON.stringify(body) }) },
      signal
    );
  }

  return {
    stats: (signal) => getJson<WireStats>('api/stats', signal),

    search(text, opts = {}, signal) {
      const params = new URLSearchParams({ q: text });
      if (opts.limit) params.set('limit', String(opts.limit));
      return getJson<WireSearch>(`api/search${query(params)}`, signal);
    },