Integration between http4s & MUnit
Integration library between MUnit and http4s.
Installation
Add the following line to your build.sbt
file:
libraryDependencies += "com.alejandrohdezma" %% "http4s-munit" % "0.9.3" % Test) // if using http4s 0.23.x
libraryDependencies += "com.alejandrohdezma" %% "http4s-munit" % "0.8.3" % Test) // if using http4s 0.22.x
libraryDependencies += "com.alejandrohdezma" %% "http4s-munit" % "0.7.3" % Test) // if using http4s 0.21.x
Usage
HttpRoutes
Testing We can use the Http4sHttpRoutesSuite
to write tests for an HttpRoutes
using Request[IO]
values easily:
import cats.effect.IO
import org.http4s._
import org.http4s.client.dsl.io._
import org.http4s.dsl.io._
import org.http4s.syntax.all._
class MyHttpRoutesSuite extends munit.Http4sHttpRoutesSuite {
override val routes: HttpRoutes[IO] = HttpRoutes.of {
case GET -> Root / "hello" => Ok("Hi")
case GET -> Root / "hello" / name => Ok(s"Hi $name")
}
test(GET(uri"hello" / "Jose")).alias("Say hello to Jose") { response =>
assertIO(response.as[String], "Hi Jose")
}
}
The test
method receives a Request[IO]
object and when the test runs, it runs that request against the provided routes and let you assert the response.
http4s-munit
will automatically name your tests using the information of the provided Request
. For example, for the test shown in the previous code snippet, the following will be shown when running the test:
munit.MyHttpRoutesSuite:0s
+ GET -> hello/Jose (Say hello to Jose) 0.014s
AuthedRoutes
Testing If we want to test authenticated routes (AuthedRoutes
in http4s) we can use the Http4sAuthedRoutesSuite
. It is completely similar to the previous suite, except that we need to ensure a Show
instance is available for the auth "context" type and that we need to provide AuthedRequest
instead of Request
in the test
definition. We can do this using its own constructor or by using our extension function context
or ->
:
import cats.effect.IO
import org.http4s._
import org.http4s.client.dsl.io._
import org.http4s.dsl.io._
import org.http4s.syntax.all._
class MyAuthedRoutesSuite extends munit.Http4sAuthedRoutesSuite[String] {
override val routes: AuthedRoutes[String, IO] = AuthedRoutes.of {
case GET -> Root / "hello" as user => Ok(s"$user: Hi")
case GET -> Root / "hello" / name as user => Ok(s"$user: Hi $name")
}
test(GET(uri"hello" / "Jose").context("alex")).alias("Say hello to Jose") { response =>
assertIO(response.as[String], "alex: Hi Jose")
}
}
Testing a remote HTTP server
In the case you don't want to use static http4s routes, but a running HTTP server, you have available the HttpSuite
. This suite behaves exactly the same as the previous ones except that you don't provide a routes
object, but a baseUri
with the URI of your HTTP server. Any Request
added in tests will prepend
this URI before making a call using a real http4s Client
(that you'll have to provide using http4sMUnitClient
).
import cats.effect.IO
import cats.effect.Resource
import io.circe.Json
import org.http4s._
import org.http4s.circe._
import org.http4s.client.Client
import org.http4s.client.dsl.io._
import org.http4s.dsl.io._
import org.http4s.ember.client.EmberClientBuilder
import org.http4s.syntax.all._
class GitHubSuite extends munit.HttpSuite {
override def http4sMUnitClient: Resource[IO, Client[IO]] = EmberClientBuilder.default[IO].build
override val baseUri: Uri = uri"https://api.github.com"
test(GET(uri"users/gutiory")) { response =>
assertEquals(response.status.code, 200)
val result = response.as[Json].map(_.hcursor.get[String]("login"))
assertIO(result, Right("gutiory"))
}
}
Testing an HTTP server running inside a container
The last of our suites can be used when you want to test a "live" container inside a test-containers container. This suite lives in a different artifact, so if you want to use it, you'll need to add the following to your build.sbt
:
libraryDependencies += "com.alejandrohdezma" %% "http4s-munit-testcontainers" % 0.9.3 % Test)
It is similar to the previous suite (in fact it extends from it) but instead of a base URI we provide a container definition:
import cats.effect.IO
import cats.effect.Resource
import org.http4s.dsl.io._
import org.http4s.client.Client
import org.http4s.client.dsl.io._
import org.http4s.ember.client.EmberClientBuilder
import org.http4s.syntax.all._
import com.dimafeng.testcontainers.GenericContainer
import com.dimafeng.testcontainers.munit.TestContainerForAll
import org.testcontainers.containers.wait.strategy.Wait
class PingPongContainerSuite extends munit.HttpFromContainerSuite with TestContainerForAll {
override def http4sMUnitClient: Resource[IO, Client[IO]] = EmberClientBuilder.default[IO].build
override val containerDef = GenericContainer.Def(dockerImage = "briceburg/ping-pong", exposedPorts = Seq(80), waitStrategy = Wait.forHttp("/ping"))
test(GET(uri"ping")) { response =>
assertEquals(response.status.code, 200)
assertIO(response.as[String], "pong")
}
}
As you can see in order to use this suite you'll need to select also one of the two test-containers specific suites: TestContainersForAll
or TestContainersForEach
. Lastly you'll need to ensure your container's URI is obtainable either by using the default extractor (which just uses localhost:first-exposed-port
) or providing an specific one for your container by overriding the http4sMUnitContainerUriExtractor
function:
override def http4sMUnitContainerUriExtractor: PartialFunction[Containers, Uri] =
super.http4sMUnitContainerUriExtractor orElse {
case _: GenericContainer => uri"http://localhost:80"
}
or
override def http4sMUnitContainerUriExtractor: PartialFunction[Containers, Uri] = {
case _: GenericContainer => uri"http://localhost:80"
}
Other features
Tagging your tests
Once the request has been passed to the test
method, we can tag our tests before implementing them:
// Marks the test as failing (it will pass if the assertion fails)
test(GET(uri"hello")).fail { response => assertEquals(response.status.code, 200) }
// Marks a test as "flaky". Check MUnit docs to know more about this feature:
// https://scalameta.org/munit/docs/tests.html#tag-flaky-tests
test(GET(uri"hello")).flaky { response => assertEquals(response.status.code, 200) }
// Skips this test when running the suite
test(GET(uri"hello")).ignore { response => assertEquals(response.status.code, 200) }
// Runs only this test when running the suite
test(GET(uri"hello")).only { response => assertEquals(response.status.code, 200) }
// We can also use our own tags, just like with MUnit `test`
val IntegrationTest = new munit.Tag("integration-test")
test(GET(uri"hello")).tag(IntegrationTest) { response => assertEquals(response.status.code, 200) }
Stress-testing
http4s-munit
includes a small feature that allows you to "stress-test" a service. Once the request has been passed to the test
method, we can call several methods to enable test repetition and parallelization:
test(GET(uri"hello"))
.repeat(50)
.parallel(10) { response =>
assertEquals(response.status.code, 200)
}
On the other hand, if you do not want to have to call these methods for each test, you also have the possibility to enable repetition and parallelization using system properties or environment variables:
-
Using environment variables:
export HTTP4S_MUNIT_REPETITIONS=50 export HTTP4S_MUNIT_MAX_PARALLEL=10 sbt test
-
Using system properties:
sbt -Dhttp4s.munit.repetitions=50 -Dhttp4s.munit.max.parallel=10 test
Also, when multiple errors occured while running repeated tests, you can control wheter http4s-munit
should output all failures or not using:
# Using environment variable
export HTTP4S_SHOW_ALL_STACK_TRACES=true
# Using system property
sbt -Dhttp4s.munit.showAllStackTraces=true test
Finally, if you want to disable repetitions for a specific test when using environment variables or system properties, you can use doNotRepeat
:
test(GET(uri"hello")).doNotRepeat { response =>
assertEquals(response.status.code, 200)
}
Nested requests
Sometimes (mostly while using the HttpSuite
or HttpFromContainerSuite
) one test needs some pre-condition in order to be executed (e.g., in order to test the deletion of a user, you need to create it first). In such cases, once the request has been passed to the test
method, we can call andThen
to provide nested requests from the response of the previous one:
test(GET(uri"posts" +? ("number" -> 10)))
.alias("look for the 10th post")
.andThen("delete it")(_.as[String].map { id =>
DELETE(uri"posts" / id)
}) { response =>
assertEquals(response.status.code, 204)
}
Test names
The generated test names can be customized by overriding http4sMUnitNameCreator
. Allows altering the name of the generated tests.
By default this method generate test names like:
// GET -> users/42
test(GET(uri"users" / "42"))
// GET -> users (all users)
test(GET(uri"users")).alias("all users")
// GET -> users - executed 10 times with 2 in parallel
test(GET(uri"users")).repeat(10).parallel(2)
// GET -> posts?number=10 (look for the 10th post and delete it)
test(GET(uri"posts" +? ("number" -> 10)))
.alias("look for the 10th post")
.andThen("delete it")(_.as[String].map { id => DELETE(uri"posts" / id) })
Body in failed assertions
http4s-munit
always includes the responses body in a failed assertion's message.
For example, when running the following suite...
import cats.effect.IO
import org.http4s._
import org.http4s.client.dsl.io._
import org.http4s.dsl.io._
import org.http4s.syntax.all._
class MySuite extends munit.Http4sHttpRoutesSuite {
val routes: HttpRoutes[IO] = HttpRoutes.pure(Response().withEntity("""{"id": 1, "name": "Jose"}"""))
test(GET(uri"users"))(response => assertEquals(response.status.code, 204))
}
...it will fail with this message:
X MySuite.GET -> users 0.042s munit.ComparisonFailException: MySuite.scala:12
12: test(GET(uri"users"))(response => assertEquals(response.status.code, 204))
values are not the same
=> Obtained
200
=> Diff (- obtained, + expected)
-200
+204
Response body was:
{
"id": 1,
"name": "Jose"
}
The body will be prettified using http4sMUnitBodyPrettifier
, which, by default, will try to parse it as JSON and apply a code highlight if munitAnsiColors
is true
. If you want a different output or disabling body-prettifying just override this method.
Response clues
Apart from the response body clues introduced in the previous section, http4s-munit
also provides a simple way to transform a response into clues: the response.clues
extension method.
The output of this extension method can be tweaked by using the http4sMUnitResponseClueCreator
.
For example, this can be used on container suites to filter logs relevant to the current request (if your logs are JSON objects containing the request id):
import cats.effect.IO
import cats.effect.Resource
import org.http4s.dsl.io._
import org.http4s.client.Client
import org.http4s.client.dsl.io._
import org.http4s.ember.client.EmberClientBuilder
import org.http4s.syntax.all._
import org.http4s.Response
import org.typelevel.ci._
import com.dimafeng.testcontainers.GenericContainer
import com.dimafeng.testcontainers.munit.TestContainerForAll
import org.testcontainers.containers.wait.strategy.Wait
class PingPongContainerSuite extends munit.HttpFromContainerSuite with TestContainerForAll {
override def http4sMUnitResponseClueCreator(response: Response[IO]) = withContainers { container =>
val id = response.headers.get(ci"x-request-id").map(_.head.value)
// Here you will filter `container.logs` using the `id`
val logs = container.logs
clues(response, logs)
}
override def http4sMUnitClient: Resource[IO, Client[IO]] = EmberClientBuilder.default[IO].build
override val containerDef = GenericContainer.Def(dockerImage = "briceburg/ping-pong", exposedPorts = Seq(80), waitStrategy = Wait.forHttp("/ping"))
test(GET(uri"ping", ci"X-Request-Id" := "1234")) { response =>
assertEquals(response.status.code, 200, response.clues)
assertIO(response.as[String], "pong", response.clues)
}
}