Function hopAt

src/ui-server/api/steps.ts:463–482

(caller: Node, at: { line?: number; column?: number }, callee?: string)

  const callAt = (caller: Node, site: { line?: number; column?: number; callee?: string }) => calls.callSite(caller, site);
  /** A hop's position with its call's span and enclosing call, read from the tree; the bare position when unreadable. */
  const hopAt = async (caller: Node, at: { line?: number; column?: number }, callee?: string): Promise<HopSite> => {
    const line = at.line ?? caller.startLine;
    const column = at.column ?? 0;
    const read = at.line ? await callAt(caller, { ...at, ...(callee ? { callee } : {}) }) : null;
    // The read must be THIS call. An inline handler's edges carry the ROUTE's
    // line (`router.post('/users/login', async (req, res) => {`), where the
    // only call is the registration itself — and taking its span would make
    // every call in the handler read as written inside it, and so as running
    // first. A miss is a bare position: no span to nest by, no `within`.
    const last = (n: string) => n.replace(/\([^()]*\)/g, '').split(/[.:]/).pop() ?? n;
    const usable = read !== null && (!callee || last(read.callee) === last(callee));
    if (!usable) return { file: caller.filePath, line, column, end: { line, column }, within: null };
    return {
      file: caller.filePath,
      line: read.span?.start.line ?? line,
      column: read.span?.start.column ?? column,
      end: read.span?.end ?? { line, column },
      within: read.within ?? null,
    };
  };
  const pointHop = (caller: Node, at: { line?: number; column?: number }): HopSite => {
    const line = at.line ?? caller.startLine;
    const column = at.column ?? 0;