Function parseStreamPartsText

src/stream-parts.ts:31–78

(text: string)

/** Parse one or more glued NDJSON stream objects from text. */
export function parseStreamPartsText(text: string): {
  parts: StreamPart[];
  rest: string;
} {
  const parts: StreamPart[] = [];
  let index = 0;

  while (index < text.length) {
    while (index < text.length && text[index] !== "{") {
      index++;
    }
    if (index >= text.length) {
      break;
    }

    let parsed: StreamPart | null = null;
    let end = -1;

    for (let cursor = index + 1; cursor <= text.length; cursor++) {
      if (text[cursor - 1] !== "}") {
        continue;
      }
      try {
        const candidate = JSON.parse(text.slice(index, cursor)) as StreamPart;
        if (
          (candidate.kind === "reasoning" || candidate.kind === "content") &&
          typeof candidate.delta === "string" &&
          candidate.delta.length > 0
        ) {
          parsed = candidate;
          end = cursor;
          break;
        }
      } catch {
        // keep extending
      }
    }

    if (!parsed || end === -1) {
      return { parts, rest: text.slice(index) };
    }

    parts.push(parsed);
    index = end;
  }

  return { parts, rest: "" };
}

/** Split corrupted saved assistant text that contains NDJSON stream parts. */
export function splitStoredStreamText(text: string): {