Function mergeSnapshotIntoSource

packages/convert/src/snapshot/merge.ts:13–93

(
  source: DeepnoteFile,
  snapshot: DeepnoteSnapshot,
  options: MergeOptions = {}
)

 * @returns A new DeepnoteFile with outputs merged in
 */
export function mergeSnapshotIntoSource(
  source: DeepnoteFile,
  snapshot: DeepnoteSnapshot,
  options: MergeOptions = {}
): DeepnoteFile {
  const { skipMismatched = false } = options

  // Build a map of block outputs from snapshot: blockId -> block with outputs
  const outputMap = new Map<
    string,
    {
      contentHash?: string
      executionCount?: number | null
      executionStartedAt?: string
      executionFinishedAt?: string
      outputs?: unknown[]
    }
  >()

  for (const notebook of snapshot.project.notebooks) {
    for (const block of notebook.blocks) {
      const execBlock = block as DeepnoteBlock & {
        executionCount?: number | null
        executionStartedAt?: string
        executionFinishedAt?: string
        outputs?: unknown[]
      }

      // Only store blocks that have outputs
      if (execBlock.outputs && execBlock.outputs.length > 0) {
        outputMap.set(block.id, {
          contentHash: block.contentHash,
          executionCount: execBlock.executionCount,
          executionStartedAt: execBlock.executionStartedAt,
          executionFinishedAt: execBlock.executionFinishedAt,
          outputs: execBlock.outputs,
        })
      }
    }
  }

  // Merge snapshot environment and execution into source
  const merged: DeepnoteFile = {
    ...source,
    environment: snapshot.environment ?? source.environment,
    execution: snapshot.execution ?? source.execution,
    project: {
      ...source.project,
      notebooks: source.project.notebooks.map(notebook => ({
        ...notebook,
        blocks: notebook.blocks.map(block => {
          const snapshotData = outputMap.get(block.id)

          if (!snapshotData) {
            // No outputs for this block
            return block
          }