Importing and Exporting Data

We can use Firebase CLI tools to import data from the gse-roar-assessment-dev Firestore database to the local Firestore emulator.

Exporting Data from Firestore

To export data from the Firestore database, use the following command:

gcloud config set project gse-roar-assessment-dev
gsutil -m rm -rf gs://roar-assessment-dev-export/emulator-exports
gcloud firestore export gs://roar-assessment-dev-export/emulator-exports --collection-ids=tasks,variants

These commands set the project to gse-roar-assessment-dev, remove the existing export of the task and variants collection, export task and variants collections to a Cloud Storage bucket named roar-assessment-dev-export.
The export metadata will be stored in the folder emulator-exports, which will be created in the bucket.
We can export other collections by changing the --collection-ids parameter, but for now, we are only exporting the tasks and variants collection.

Note: You may need to install the gcloud CLI and authenticate with your Google Cloud account to run these commands.

Note: Instead of overwriting the existing export, you can instead set the export path to a new folder in the bucket if you wish.

Note: You may need specific IAM permissions in order to read and write to the Cloud Storage bucket in the gse-roar-assessment-dev project.**

Importing Data into the Firestore Emulator

We need to import the exported data into the local Firestore emulator. To do this, we need to download the exported data from the Cloud Storage bucket and then import it into the emulator.

Downloading the Exported Data

To download the exported data from the Cloud Storage bucket, use the following command:

gsutil -m cp -r gs://roar-assessment-dev-export/emulator-exports . 

This command downloads the exported data from the roar-assessment-dev-export bucket to the current directory. The metadata will be stored in the emulator-exports folder. Firebase uses this metadata to import the data into the Firestore emulator.

Note: If you wrote the export to a different folder in the bucket, you will need to change the path in the gsutil cp command accordingly.

Importing the Data into the Firestore Emulator

To import the downloaded data into the Firestore emulator, use the following command:

npx firebase emulators:start --project=gse-roar-assessment-dev --import=./emulator-exports --export-on-exit=./emulator-exports

Note: If you wrote the export to a different folder in the bucket, you will need to change the path in the --import and --export-on-exit parameters accordingly.

Note: You may need to install the firebase-tools package globally to use the firebase command.

This command starts the Firestore emulator for the gse-roar-assessment-dev project, imports the data from the emulator-exports folder, and exports any changes back to the emulator-exports folder when the emulator is stopped. This allows us to persist any changes made during testing.