wipe-tables.ts

wipe-tables.ts

/**
 * Wipes all items from every DynamoDB table whose name starts with the given
 * prefix.
 *
 * Lists all tables in the account, keeps the ones matching the prefix, and for
 * each one scans every item (projecting only the key attributes) and deletes
 * them in batches of 25 via `BatchWriteItem`. Tables with deletion protection
 * enabled are skipped. The table itself is left in place — only its contents
 * are removed.
 *
 * Intended as an operator script for tearing down CI stack data.
 *
 * Usage:
 *   node --experimental-transform-types --no-warnings wipe-tables.ts [prefix]
 */
import {
	BatchWriteItemCommand,
	DescribeTableCommand,
	DynamoDBClient,
	paginateListTables,
	paginateScan,
} from '@aws-sdk/client-dynamodb'

const db = new DynamoDBClient()

const prefix = process.argv[2]
if (prefix === undefined) {
	console.error('Usage: ts-node wipe-tables.ts [prefix]')
	process.exit(1)
}

// Get all tables prefixed with the provided prefix
const tables: string[] = []
for await (const { TableNames } of paginateListTables({ client: db }, {})) {
	tables.push(...(TableNames ?? []).filter((name) => name.startsWith(prefix)))
}

for (const TableName of tables) {
	const { Table } = await db.send(new DescribeTableCommand({ TableName }))

	// Check that deletion protection is disabled
	if (Table?.DeletionProtectionEnabled === true) {
		console.log(`Skipping ${TableName}: deletion protection is enabled`)
		continue
	}

	const keyAttributes = (Table?.KeySchema ?? []).map(
		({ AttributeName }) => AttributeName as string,
	)

	// Delete all items in the table
	let deleted = 0
	let batch: Record<string, unknown>[] = []
	const flush = async () => {
		if (batch.length === 0) return
		await db.send(
			new BatchWriteItemCommand({
				RequestItems: {
					[TableName]: batch.map((Key) => ({
						DeleteRequest: { Key: Key as never },
					})),
				},
			}),
		)
		deleted += batch.length
		batch = []
	}

	for await (const { Items } of paginateScan(
		{ client: db },
		{
			TableName,
			ProjectionExpression: keyAttributes.map((_, i) => `#k${i}`).join(', '),
			ExpressionAttributeNames: Object.fromEntries(
				keyAttributes.map((name, i) => [`#k${i}`, name]),
			),
		},
	)) {
		for (const item of Items ?? []) {
			batch.push(item)
			// BatchWriteItem allows at most 25 requests per call
			if (batch.length === 25) await flush()
		}
	}
	await flush()

	console.log(`Wiped ${TableName}: deleted ${deleted} items`)
}