Firebase backup to CSV

A Node.js cli helper tool to transform firebase JSON backup to multiple CSV files (one for each collection)

Purpose

• Migration from Firebase to Supabase: Supabase allows users to upload a csv tables.
• Firebase allows documents in a collection to have different structures. Example:

  [Collection]: {
    abcde: {
      name: ..,
      text: ..,
      updatedAt: ..,
    },
    fghi: {
      name: ..,
      text: ..,
      updatedAt: ..,
      optional: ..
    }
  }

  Which can cause problems for csv files. The tool takes the document with the largest number of keys and uses these keys as the header fo the csv file.
• Remark: Of course, if the data in each of your documents has a complete different structure you can't export it in csv format because columns will "leak" down rows.

Requirement

• JSON file format:

  {
    collection1: {
      id1: {
        ..
      },
      id2: {
        ..
      }
    },
    ..
    collection100: {
      ..
    }
  }

Usage

npx firebase-backup-to-csv <path_to_json_backup> Will generate all the csv files in the same folder where the json backup is located.

Helpers

1. Usually Firebase fetches each collection as an array of objects, where each object is a document with the id as a hidden property (which won't get exported):

[
  {
    id: <hidden>
    ..
  },
  {
    ..
  }
]

Therefore, it's necessary to transform each collection to be an object of objects:

let newBlogPostsCollection = {}
// blogPostsCollection is an array of objects
blogPostsCollection.forEach((document, i) => {
 const id = document.id
 delete document.id
 newBlogPostsCollection[id] = {...document}
})
.
.
.
const collections = {blogPosts: blogPostsCollection, ...}

2. Firebase in blaze plan doesn't allow users to automatically generate backups,therefore we will export collections as a json file:

const collectionsData = new Blob([collections], { type: "application/json" })
const csvUrl = URL.createObjectURL(collectionsData)

const hiddenElement = document.createElement("a")
hiddenElement.href = csvUrl
hiddenElement.target = "_blank"
hiddenElement.download = "backup.json"
hiddenElement.click()