initial commit

src/cli.ts

@@ -0,0 +1,20 @@
+#!/usr/bin/env node
+
+import { Command } from 'commander'
+import spec from '../package.json'
+import { migrate } from './'
+
+const program = new Command()
+program.version(spec.version).name(spec.name)
+
+program
+  .command('migrate')
+  .description('run migrations')
+  // .option('--dry-run', 'run simulation without committing changes')
+  .option('-m, --migrations <glob>', 'migration files', './migrations/*.js')
+  .option('--force', 'ignore remote state and rerun migrations')
+  .action(async (args) => {
+    await migrate({ directory: args.migrations, ignoreRemote: args.force })
+  })
+
+program.parse(process.argv)

src/index.ts

@@ -0,0 +1,117 @@
+import crypto from 'crypto'
+import path from 'path'
+import admin from 'firebase-admin'
+import semver from 'semver'
+import glob from 'glob'
+import chalk from 'chalk'
+
+const App = admin.initializeApp()
+const DB = admin.firestore()
+const Timestamp = admin.firestore.Timestamp
+const MigrationCollection = DB.collection('migrations')
+
+export type MigrationFN = (db: FirebaseFirestore.Firestore, firestore: typeof admin.firestore) => Promise<void>
+export type MigrationFile = {
+  version: string
+  name: string
+  fn: MigrationFN
+}
+
+enum MigrationResultStatus {
+  Successful = 'successful',
+  Failed = 'failed',
+}
+type MigrationResult = {
+  executed: FirebaseFirestore.Timestamp
+  version: string
+  status: MigrationResultStatus
+}
+
+export type Options = {
+  directory: string
+  delimiter: string
+  ignoreRemote: boolean
+}
+
+const defaults: Options = {
+  directory: './migrations',
+  delimiter: '__',
+  ignoreRemote: false,
+}
+
+const extension = /\..*$/
+
+async function gather(options: Options): Promise<MigrationFile[]> {
+  const files = glob
+    .sync(path.join(options.directory, '*.js'))
+    .filter((f) => f.includes(options.delimiter))
+    .map((f) => path.resolve(f))
+
+  const versions: string[] = []
+  const contents = await Promise.all(
+    files.map(async (f) => {
+      const [rawVersion, name] = path.basename(f).split(options.delimiter)
+
+      const version = semver.coerce(rawVersion)
+      if (!version) throw new Error(`Invalid version: "${rawVersion}".`)
+      if (versions.includes(version.version))
+        throw new Error(`Cannot have multiple files for version: ${version.version}`)
+      versions.push(version.version)
+      const migration = await import(f)
+      if (typeof migration.migration !== 'function') throw new Error(`No migrate function found in: ${f}`)
+      return {
+        version,
+        name: name.replace(extension, ''),
+        fn: migration.migration as MigrationFN,
+      }
+    })
+  )
+
+  const sorted = contents.sort((a, b) => (semver.gt(a.version, b.version) ? 1 : -1))
+  return sorted.map(({ version, ...rest }) => ({
+    ...rest,
+    version: version.version,
+  }))
+}
+
+function getIdFromMigration(migration: MigrationFile): string {
+  return crypto.createHash('sha256').update(migration.version).digest('hex')
+}
+
+function printMigration(migration: MigrationFile, msg: string) {
+  console.log(chalk.underline(`Migration ${chalk.bold(migration.version)}:`), msg)
+}
+
+async function runMigrations(migrations: MigrationFile[], options: Options) {
+  for (const migration of migrations) {
+    const id = getIdFromMigration(migration)
+    const remoteDoc = await MigrationCollection.doc(id).get()
+    const remote = remoteDoc.data() as MigrationResult | undefined
+    if (!options.ignoreRemote && remote && remote.status === MigrationResultStatus.Successful) {
+      printMigration(migration, '🔧 Already run.')
+      continue
+    }
+
+    const result: MigrationResult = {
+      version: migration.version,
+      executed: Timestamp.now(),
+      status: MigrationResultStatus.Successful,
+    }
+    try {
+      await migration.fn(DB, admin.firestore)
+      await remoteDoc.ref.set(result)
+      printMigration(migration, chalk.green(`✅ Success`))
+    } catch (e) {
+      await remoteDoc.ref.set({ ...result, status: MigrationResultStatus.Failed })
+      printMigration(migration, chalk.red(`❌ Error while running.`))
+      console.error(e)
+      break
+    }
+  }
+}
+
+export async function migrate(options?: Partial<Options>) {
+  const merged: Options = Object.assign(defaults, options)
+  const migrations = await gather(merged)
+  await runMigrations(migrations, merged)
+}