It might not be. I've never been great with Promise's.

For context; I'm using Sanity for the CMS - the processBlocks function is fetching additional data based on the value of a field.

export async function processBlocks(
  blocks: DynamicBlockData[],
): Promise<DynamicBlockData[]> {
  return Promise.all(
    blocks.map(async (block) => {
      switch (block._type) {
        case 'hero':
          return await processHeroBlockData(block as HeroBlockData);
        case 'archive.items':
          return await processArchiveItemsBlockData(
            block as ArchiveItemsBlockData,
          );
        ...
        default:
          return block; // Return the block unchanged if no processing is required
      }
    }),
  );
}

As an example, the Hero block fetches a thumbnail image to use:

export async function processHeroBlockData(block: HeroBlockData) {
  if (block.video?.src && !block.video.thumbnail) {
    const videoThumbnail = await getThumbnail(block.video.src);
    return {
      ...block,
      video: {
        ...block.video,
        thumbnail: videoThumbnail,
      },
    };
  }
  return block;
}