Move Follow to a component

src/main/kotlin/component/follow/routes/article/FollowArticle.kt

@@ -0,0 +1,31 @@
+package fr.dcproject.component.follow.routes.article
+
+import fr.dcproject.component.article.ArticleRef
+import fr.dcproject.component.auth.citizen
+import fr.dcproject.component.auth.citizenOrNull
+import fr.dcproject.component.follow.FollowArticleRepository
+import fr.dcproject.component.follow.FollowForUpdate
+import fr.dcproject.component.follow.FollowVoter
+import fr.dcproject.voter.assert
+import io.ktor.application.call
+import io.ktor.http.HttpStatusCode
+import io.ktor.locations.KtorExperimentalLocationsAPI
+import io.ktor.locations.Location
+import io.ktor.locations.post
+import io.ktor.response.respond
+import io.ktor.routing.Route
+
+@KtorExperimentalLocationsAPI
+object FollowArticle {
+    @Location("/articles/{article}/follows")
+    class ArticleFollowRequest(val article: ArticleRef)
+
+    fun Route.followArticle(repo: FollowArticleRepository, voter: FollowVoter) {
+        post<ArticleFollowRequest> {
+            val follow = FollowForUpdate(target = it.article, createdBy = this.citizen)
+            voter.assert { canCreate(follow, citizenOrNull) }
+            repo.follow(follow)
+            call.respond(HttpStatusCode.Created)
+        }
+    }
+}