Function resolveAndComposeInit

packages/convert/src/snapshot/resolve-init.ts:117–232

(loaded: LoadedRunnableFile)

/** Resolves the init notebook for a `DeepnoteFile`, composing `[init, ...notebooks]` from a sibling `.deepnote` when not self-contained, else failing closed. */
export async function resolveAndComposeInit(loaded: LoadedRunnableFile): Promise<ResolveAndComposeInitResult> {
  const filePath = loaded.originalPath
  const initNotebookId = loaded.file.project.initNotebookId
  const warnings: string[] = []

  if (initNotebookId === undefined) {
    return { ...loaded, warnings }
  }

  const localInit = loaded.file.project.notebooks.find(nb => nb.id === initNotebookId)
  if (localInit !== undefined) {
    return { ...loaded, warnings }
  }

  const directory = dirname(filePath)
  const ownBasename = basename(filePath)

  let entries: string[]
  try {
    entries = await fs.readdir(directory)
  } catch (error) {
    const message = error instanceof Error ? error.message : String(error)
    throw new Error(
      `Cannot resolve init notebook for ${filePath}: failed to read directory ${directory}.\n` +
        `initNotebookId: ${initNotebookId}\n` +
        `Error: ${message}`
    )
  }

  const matches: Array<{ path: string; file: DeepnoteFile }> = []
  const rejected: RejectedCandidate[] = []

  for (const entry of entries) {
    if (entry === ownBasename) continue
    const lowerEntry = entry.toLowerCase()
    // Snapshots are single-notebook `.deepnote` files that share the source's project/notebook
    // ids, so they would validate as init candidates — exclude them to avoid spurious ambiguity.
    if (lowerEntry.endsWith('.snapshot.deepnote')) continue
    if (!lowerEntry.endsWith('.deepnote')) continue

    const candidatePath = resolve(directory, entry)

    let candidate: DeepnoteFile
    try {
      const rawBytes = await fs.readFile(candidatePath)
      const content = decodeUtf8NoBom(rawBytes)
      candidate = deserializeDeepnoteFile(content)
    } catch (error) {
      const message = error instanceof Error ? error.message : String(error)
      rejected.push({ path: candidatePath, reason: `failed to parse: ${message}` })
      continue
    }

    const validation = isValidSiblingInitCandidate(candidate, loaded.file.project.id, initNotebookId)
    if (!validation.valid) {
      rejected.push({ path: candidatePath, reason: validation.reason })
      continue
    }