Preview databases

Give every pull request a copy of your staging database. Each preview gets real data to test with, and is deleted when you’re done.

Each preview copies staging's database as it is when the PR deploys, runs the PR's own migrations on the copy, and is deleted with the PR. Staging never changes.

Read the stage

import * as Alchemy from "alchemy";

const { stage } = yield* Alchemy.Stack;
const preview = stage.startsWith("pr-");

Reuse staging’s group

const group = preview
  ? yield* Turso.Group.ref("Group", { stage: "staging" })
  : yield* Turso.Group("Group", { location: "aws-us-east-1" });

Turso.Group.ref uses the group from the staging stage. Previews never create or delete it.

Copy staging’s database

const source = preview ? yield* Turso.Database.ref("Db", { stage: "staging" }) : undefined;

const db = yield* Turso.Database("Db", {
  group: group.name,
  seed: source ? { type: "database", name: source.name } : undefined,
  migrations: "./migrations",
});

Each preview gets its own copy of staging’s database, then runs any new migrations from the pull request.

Tear it down

alchemy destroy --stage pr-42

This deletes the preview’s database. Staging’s group and database stay.

Where next

• Databases
• Migrations