OpenAPI contracts/routing

App.kt

/*
 * This Kotlin source file was generated by the Gradle 'init' task.
 */
package com.test.openapi

import com.fasterxml.jackson.databind.DeserializationFeature
import com.fasterxml.jackson.module.kotlin.KotlinModule
import com.test.openapi.Jackson.auto
import org.http4k.contract.contract
import org.http4k.contract.div
import org.http4k.contract.meta
import org.http4k.contract.openapi.ApiInfo
import org.http4k.contract.openapi.v3.OpenApi3
import org.http4k.contract.openapi.v3.OpenApi3ApiRenderer
import org.http4k.contract.security.ApiKeySecurity
import org.http4k.core.Body
import org.http4k.core.Filter
import org.http4k.core.HttpHandler
import org.http4k.core.HttpTransaction
import org.http4k.core.Method
import org.http4k.core.Response
import org.http4k.core.Status.Companion.OK
import org.http4k.core.then
import org.http4k.core.with
import org.http4k.filter.CorsPolicy
import org.http4k.filter.ResponseFilters
import org.http4k.filter.ServerFilters
import org.http4k.format.ConfigurableJackson
import org.http4k.format.asConfigurable
import org.http4k.format.withStandardMappings
import org.http4k.lens.Path
import org.http4k.lens.Query
import org.http4k.lens.int
import org.http4k.routing.bind
import org.http4k.routing.routes
import org.http4k.server.Jetty
import org.http4k.server.asServer
import java.time.Clock

class App {
    val greeting: String
        get() {
            return "Hello world."
        }
}

object Jackson : ConfigurableJackson(
    KotlinModule()
    .asConfigurable()
    .withStandardMappings()
    .done()
    .deactivateDefaultTyping()
    .configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false)
    .configure(DeserializationFeature.FAIL_ON_IGNORED_PROPERTIES, false)
    .configure(DeserializationFeature.USE_BIG_DECIMAL_FOR_FLOATS, true)
    .configure(DeserializationFeature.USE_BIG_INTEGER_FOR_INTS, true)
)

data class SumResult(val sum: Int)
val sumResponseBody = Body.auto<SumResult>().toLens()

fun main(args: Array<String>) {
    fun add(value1: Int, value2: Int): HttpHandler = {
        Response(OK).with(
            sumResponseBody of SumResult(value1 + value2)
        )
    }

    val filter: Filter = ResponseFilters.ReportHttpTransaction(Clock.systemUTC()) { tx: HttpTransaction ->
        println(tx.labels.toString() + " took " + tx.duration)
    }

    val mySecurity = ApiKeySecurity(Query.int().required("apiKey"), { it == 42 })

    val contract = contract {
        renderer = OpenApi3(ApiInfo("my great api", "v1.0"), Jackson, emptyList(), OpenApi3ApiRenderer(Jackson))
        descriptionPath = "/docs/swagger.json"
        security = mySecurity

        routes += "/add" / Path.int().of("value1") / Path.int().of("value2") meta {
            summary = "add"
            description = "Adds 2 numbers together"
            returning(OK, sumResponseBody to SumResult(55))
        } bindContract Method.GET to ::add
    }

    val handler = routes(
        "/context" bind filter.then(contract),
        "/" bind contract {
            renderer = OpenApi3(ApiInfo("my great super api", "v1.0"), Jackson, emptyList(), OpenApi3ApiRenderer(Jackson))
        }
    )

    ServerFilters.Cors(CorsPolicy.UnsafeGlobalPermissive).then(handler).asServer(Jetty(8000)).start()
}