migrate-blob

A small library to migrate a specific list of blobs from global blob storage (account-wide, Cloudflare R2) to scoped blob storage (per-val, S3).

Migration streams the raw body of each blob, so it is safe for binary, text, and JSON alike, and preserves keys exactly. Defaults are conservative: dry-run, no overwrite, and copy (not move).

Library usage

Import migrateBlobs from main.ts:


import { migrateBlobs } from "https://esm.town/v/nbbaier/migrate-blob/main.ts";

const summary = await migrateBlobs(["my-config", "images/logo.png"], {
  commit: true, // default false (dry run)
});

console.log(summary.counts);
// { ok, skip, miss, dry, err }

`migrateBlobs(targets, options)`

Option	Default	Behavior
`prefix`	`false`	When `true`, targets are expanded as prefixes into global keys.
`commit`	`false`	When `false`, nothing is written — only reports what would happen.
`overwrite`	`false`	When `false`, keys already in scoped storage are skipped (idempotent).
`deleteSource`	`false`	When `true`, deletes from global after a successful copy (i.e. a move). Ignored unless `commit`.
`onProgress`	—	Callback `(result) => void` invoked after each key.

Returns a MigrateSummary: { results, counts, dryRun }, where each result is { key, status, sourceDeleted?, error? }.

Result statuses

ok — copied from global to scoped.
skip — already present in scoped storage (re-run safe).
miss — not found in global storage.
dry — would have migrated, but commit was false.
err — see the error field.

How it works

Rendering mermaid diagram...

Notes

Global and scoped blobs are stored separately; you can't reach one through the other's interface — hence this migration.
Keys can be up to 512 chars. Total storage counts toward your plan limit (1 GB on Pro); during a copy (not move) the data exists in both stores.