Function streamRenderedMessages

src/utils/exportRenderer.tsx:55–85

(messages: Message[], tools: Tools, sink: (ansiChunk: string) => void | Promise<void>, {
  columns,
  verbose = false,
  chunkSize = 40,
  onProgress
}: {
  columns?: number;
  verbose?: boolean;
  chunkSize?: number;
  onProgress?: (rendered: number) => void;
} = {})

 * which chunk each landed in.
 */
export async function streamRenderedMessages(messages: Message[], tools: Tools, sink: (ansiChunk: string) => void | Promise<void>, {
  columns,
  verbose = false,
  chunkSize = 40,
  onProgress
}: {
  columns?: number;
  verbose?: boolean;
  chunkSize?: number;
  onProgress?: (rendered: number) => void;
} = {}): Promise<void> {
  const renderChunk = (range: readonly [number, number]) => renderToAnsiString(<AppStateProvider>
        <StaticKeybindingProvider>
          <Messages messages={messages} tools={tools} commands={[]} verbose={verbose} toolJSX={null} toolUseConfirmQueue={[]} inProgressToolUseIDs={new Set()} isMessageSelectorVisible={false} conversationId="export" screen="prompt" streamingToolUses={[]} showAllInTranscript={true} isLoading={false} renderRange={range} />
        </StaticKeybindingProvider>
      </AppStateProvider>, columns);

  // renderRange indexes into the post-collapse array whose length we can't
  // see from here — normalize splits each Message into one NormalizedMessage
  // per content block (unbounded per message), collapse merges some back.
  // Ceiling is the exact normalize output count + chunkSize so the loop
  // always reaches the empty slice where break fires (collapse only shrinks).
  let ceiling = chunkSize;
  for (const m of messages) ceiling += normalizedUpperBound(m);
  for (let offset = 0; offset < ceiling; offset += chunkSize) {
    const ansi = await renderChunk([offset, offset + chunkSize]);
    if (stripAnsi(ansi).trim() === '') break;
    await sink(ansi);
    onProgress?.(offset + chunkSize);
  }
}

/**
 * Renders messages to a plain text string suitable for export.