PostgreSQL Testcontainer that allows restting the database without dropping the schema in between test runs

resettablePostgreSQLContainer.ts

import { PostgreSqlContainer, StartedPostgreSqlContainer } from "@testcontainers/postgresql"

class ResettablePostgreSqlContainer extends PostgreSqlContainer {
    private dumpSaveDirectory: string = ""

    override async start(): Promise<StartedResettablePostgreSqlContainer> {
        const container = await super.start()

        return new StartedResettablePostgreSqlContainer(this.dumpSaveDirectory, container)
    }

    withDumpSaveLocation(dir: string): ResettablePostgreSqlContainer {
        this.withBindMounts([
            {
                source: dir,
                target: "/tmp"
            }
        ])
        this.dumpSaveDirectory = dir

        return this
    }
}

class StartedResettablePostgreSqlContainer extends StartedPostgreSqlContainer {
    private readonly dbDumpPath: string

    constructor(
        dumpSaveDirectory: string,
        container: StartedPostgreSqlContainer
    ) {
        if (dumpSaveDirectory.length === 0) {
            throw new Error(`Cannot save DB schema without a path, provide a location using "withDumpSaveLocation(string)" when starting the container!`)
        }

        super(container, container.getDatabase(), container.getUsername(), container.getPassword())
        this.dbDumpPath = `${dumpSaveDirectory}/pg_container_${this.getId()}.dump`
    }

    private async runPostgresCommand(
        cmd: string
    ): Promise<void> {
        const result = await this.exec(cmd.split(' '))

        if (result.exitCode > 0) {
            throw new Error(JSON.stringify(result.output))
        }
    }

    public async saveDatabaseSchema(
        dbPort: number = 5432
    ): Promise<void> {
        const dbConnectionPart = `-h localhost -p ${dbPort} -U ${this.getUsername()}`
        const dbName = this.getDatabase()

        await this.runPostgresCommand(`pg_dump ${dbConnectionPart} -s -f ${this.dbDumpPath} -F tar ${dbName}`)
    }

    public async resetDatabaseToSavedSchema(
        dbPort: number = 5432
    ): Promise<void> {
        const dbConnectionPart = `-h localhost -p ${dbPort} -U ${this.getUsername()}`
        const dbName = this.getDatabase()

        await this.runPostgresCommand(`dropdb ${dbConnectionPart} ${dbName}`)
        await this.runPostgresCommand(`createdb ${dbConnectionPart} ${dbName}`)
        await this.runPostgresCommand(`pg_restore ${dbConnectionPart} -s -d ${dbName} ${this.dbDumpPath}`)
    }
}

export { ResettablePostgreSqlContainer, StartedResettablePostgreSqlContainer }