使用测试容器测试Doobie解释器

Question

我正在尝试使用Testcontainers库测试一些用doobie开发的SQL语句。详细地说，我使用了以下依赖项：

"org.testcontainers" % "testcontainers" % "1.17.3" % Test,
"org.testcontainers" % "postgresql"     % "1.17.3" % Test

我的域模型很简单：

final case class Company(id: Int, name: String, description: String)

我使用init脚本在PostgreSQL上创建表：

CREATE TABLE companies (
  id serial NOT NULL,
  name text NOT NULL,
  description text
);

ALTER TABLE companies
ADD CONSTRAINT pk_companies PRIMARY KEY (id);

我正在尝试开发一个验证插入新Company的集成测试。我用的是scalatest

"org.scalatest" %% "scalatest"                     % scalaTestVersion           % Test,
"org.typelevel"  %% "cats-effect-testing-scalatest" % scalaTestCatsEffectVersion % Test

测试代码如下：

class CompaniesSpec extends AsyncFreeSpec with AsyncIOSpec with BeforeAndAfter with Matchers {

  private val transactor: Resource[IO, Transactor[IO]] = for {
    postgres <- makePostgres
    ce       <- ExecutionContexts.fixedThreadPool[IO](1)
    xa <- HikariTransactor.newHikariTransactor[IO](
      "org.postgresql.Driver",
      postgres.getJdbcUrl,
      postgres.getUsername,
      postgres.getPassword,
      ce
    )
  } yield xa

  private def makePostgres =
    Resource.make(IO {
      val container: PostgreSQLContainer[Nothing] =
        new PostgreSQLContainer().withInitScript("sql/companies.sql")
      container.start()
      container
    })(c => IO(c.stop()))

  "Companies algebra " - {
    "should create a new Company" in {
      (for {
        companyId    <- transactor.use { xa =>
          sql"INSERT INTO companies (name, description) VALUES ('My Company', 'My Company Description')"
            .update
            .withUniqueGeneratedKeys[Int]("id")
            .transact(xa)
        }
        maybeCompany <- transactor.use { xa =>
          sql"SELECT * FROM companies WHERE id = $companyId"
            .query[Company]
            .option
            .transact(xa)
        }
      } yield maybeCompany)
        .asserting { company =>
          company shouldBe defined
          company.get.name shouldBe "My Company"
          company.get.description shouldBe "My Company Description"
        }
    }
  }
}

但是，测试的断言失败，出现以下错误，这表明代码没有将任何内容插入数据库。

None was not defined
ScalaTestFailureLocation: com.rockthejvm.board.playground.algebras.CompaniesSpec at (CompaniesSpec.scala:68)

我真不明白为什么考试不及格。有谁可以帮我？

Answer 1

makePostgres是一个Resource，您可以将它与HikariTransactor组合成transaction Resource。这意味着每次调用transaction.use{ ... }时，都会启动一个新容器，并启动一个新的hikari连接池。当use中的代码完成时，这两个代码都会停止。

因为这两个查询都在不同的transactor.use{ ... }块中执行，所以它们都运行在不同的容器中和不同的连接池上。

相反，您应该确保在整个测试过程中使用相同的资源。

transactor.use { xa =>
  for {
    companyId    <-
      sql"INSERT INTO companies (name, description) VALUES ('My Company', 'My Company Description')"
        .update
        .withUniqueGeneratedKeys[Int]("id")
        .transact(xa)
    maybeCompany <- 
      sql"SELECT * FROM companies WHERE id = $companyId"
        .query[Company]
        .option
        .transact(xa)
  } yield maybeCompany
}
.asserting { company =>
  company shouldBe defined
  company.get.name shouldBe "My Company"
  company.get.description shouldBe "My Company Description"
}