#166: Add documentation to tapiro (closes #166)

build.sbt

@@ -176,12 +176,17 @@ lazy val docs = project
     moduleName := "retro-docs",
     libraryDependencies ++= docsDependencies,
     mdocVariables := Map(
+      "CIRCE_VERSION" -> V.circe,
+      "AKKA_HTTP_VERSION" -> V.akkaHttp,
+      "TAPIR_VERSION" -> V.tapir,
       "TOCTOC_SNAPSHOT_VERSION" -> version.in(toctocCore).value,
       "TOCTOC_STABLE_VERSION" -> version.in(toctocCore).value.replaceFirst("\\+.*", ""),
       "ENUMERO_SNAPSHOT_VERSION" -> version.in(enumeroCore).value,
       "ENUMERO_STABLE_VERSION" -> version.in(enumeroCore).value.replaceFirst("\\+.*", ""),
       "SBT_BUILDO_SNAPSHOT_VERSION" -> version.in(`sbt-buildo`).value,
       "SBT_BUILDO_STABLE_VERSION" -> version.in(`sbt-buildo`).value.replaceFirst("\\+.*", ""),
+      "SBT_TAPIRO_SNAPSHOT_VERSION" -> version.in(`sbt-tapiro`).value,
+      "SBT_TAPIRO_STABLE_VERSION" -> version.in(`sbt-tapiro`).value.replaceFirst("\\+.*", ""),
     ),
   )
   .dependsOn(toctocCore, enumeroCore, toctocSlickPostgreSql)

docs/tapiro/installation.md

@@ -0,0 +1,89 @@
+---
+id: installation
+title: Installation
+---
+
+`tapiro` can be installed as an Sbt plugin.
+
+`sbt-tapiro` is an Sbt plugin that uses `tapiro` to generate http/json routes parsing scala traits definitions.
+
+## Installation
+
+To start using `sbt-tapiro` simply add this line in `project/plugins.sbt`
+
+```scala
+addSbtPlugin("io.buildo" %% "sbt-tapiro" % "@SBT_TAPIRO_STABLE_VERSION@")
+```
+
+### Snapshot releases
+
+We publish a snapshot version on every merge on master.
+
+The latest snapshot version is `@SBT_TAPIRO_SNAPSHOT_VERSION@` and you can use
+it to try the latest unreleased features. For example:
+
+```scala
+addSbtPlugin("io.buildo" %% "sbt-tapiro" % "@SBT_TAPIRO_SNAPSHOT_VERSION@")
+resolvers += Resolver.sonatypeRepo("snapshots")
+```
+
+## Plugin
+
+To use the code generator, you need to add this to your `build.sbt`.
+
+```scala
+import _root_.io.buildo.tapiro.Server
+
+lazy val application = project
+  .settings(
+    libraryDependencies ++= applicationDependencies ++ tapiroDependencies,
+    tapiro / tapiroRoutesPaths := List("[path to routes]"),
+    tapiro / tapiroModelsPaths := List("[path to models]"),
+    tapiro / tapiroOutputPath := "[path to endpoints]",
+    tapiro / tapiroEndpointsPackages := List("[package]", "[subpackage]"),
+    tapiro / tapiroServer := Server.AkkaHttp, //or Server.Http4s
+  )
+  .enablePlugins(SbtTapiro)
+```
+
+You can now run it with `sbt application/tapiro`.
+
+```scala
+## Dependencies
+
+The generated code comes with library dependencies.
+
+In case akka-http version is used:
+```scala
+val V = new {
+  val circe = "@CIRCE_VERSION@"
+  val tapir = "@TAPIR_VERSION@"
+  val akkaHttp = "@AKKA_HTTP_VERSION@"
+}
+
+val tapiroDependencies = Seq(
+  "com.softwaremill.sttp.tapir" %% "tapir-json-circe" % V.tapir,
+  "com.softwaremill.sttp.tapir" %% "tapir-core" % V.tapir,
+  "com.softwaremill.sttp.tapir" %% "tapir-akka-http-server" % V.tapir,
+  "com.typesafe.akka" %% "akka-http" % V.akkaHttp,
+  "io.circe" %% "circe-core" % V.circe,
+)
+```
+
+In case http4s is used:
+
+```scala
+val V = new {
+  val circe = "@CIRCE_VERSION@"
+  val tapir = "@TAPIR_VERSION@"
+}
+
+val tapiroDependencies = Seq(
+  "com.softwaremill.sttp.tapir" %% "tapir-json-circe" % V.tapir,
+  "com.softwaremill.sttp.tapir" %% "tapir-core" % V.tapir,
+  "com.softwaremill.sttp.tapir" %% "tapir-http4s-server" % V.tapir,
+  "io.circe" %% "circe-core" % V.circe,
+)
+```
+
+These dependencies usually go under `project/Dependencies.scala`

docs/tapiro/introduction.md

@@ -0,0 +1,124 @@
+---
+id: introduction
+title: Introduction
+---
+
+Tapiro parses your Scala controllers to generate HTTP endpoints.
+
+A Scala controller is a trait defined as follows:
+
+```scala mdoc
+import scala.annotation.StaticAnnotation
+
+class query extends StaticAnnotation
+class command extends StaticAnnotation
+
+case class Cat(name: String)
+case class Error(msg: String)
+
+trait Cats[F[_], AuthToken] {
+  @query //translate this to a GET
+  def findCutestCat(): F[Either[Error, Cat]]
+
+  @command //translate this to a POST
+  def doSomethingWithTheCat(catId: Int, token: AuthToken): F[Either[Error, Unit]]
+}
+```
+
+For each controller tapiro generates two files:
+- `CatsEndpoints.scala` containing the HTTP api description using https://tapir-scala.readthedocs.io/
+- `CatsHttp4sEndpoints.scala` or `CatsAkkaHttpEndpoints.scala` depeneding on the HTTP server the user is using.
+
+## Complete Example
+
+Here you have an example implementation of the `Cats` controller definied in the previous section:
+
+```scala mdoc
+import cats.effect._
+
+object Cats {
+  def create[F[_]](implicit F: Sync[F]) = new Cats[F, String] {
+    override def findCutestCat(): F[Either[Error, Cat]] =
+      F.delay(Right(Cat("Cheshire")))
+    override def doSomethingWithTheCat(catId: Int, token: String): F[Either[Error, Unit]] =
+      F.delay(Right(()))
+  }
+}
+
+
+```
+
+Here you have the autogenerated magic fromo tapiro (This is the content of `CatsHttp4sEndpoints.scala` it will be autogenerated).
+
+```scala mdoc
+import org.http4s.HttpRoutes
+
+// ---- begins autogenerated code
+object CatsHttp4sEndpoints {
+  def routes(controller: Cats[IO, String]): HttpRoutes[IO] = ???
+}
+// ---- ends autogenerated code
+```
+
+Here is how to run the server:
+
+```scala mdoc
+import org.http4s.server.blaze._
+import org.http4s.implicits._
+import cats.implicits._
+
+object Main extends IOApp {
+  val catsImpl = CatsImpl.create[IO]
+  val routes = CatsHttp4sEndpoints.routes(catsImpl)
+
+  override def run(args: List[String]): IO[ExitCode] =
+    BlazeServerBuilder[IO]
+      .bindHttp(8080, "localhost")
+      .withHttpApp(routes.orNotFound)
+      .serve
+      .compile
+      .drain
+      .as(ExitCode.Success)
+}
+```
+
+The resulting server can be queried as follows:
+```
+/GET /Cats/findCutestCat
+/POST /Cats/doSomethingWithTheCat -d '{ "catId": 1 }'
+```
+
+## Authentication
+
+An `AuthToken` type argument is expected in each controller and is added as authorization header.
+
+`trait Cats[F[_], AuthToken]`
+
+The actual implementation of the `AuthToken` is left to the user. All tapiro requires is a proper tapir `PlainCodec` such as:
+
+```scala mdoc
+import sttp.tapir._
+import sttp.tapir.Codec._
+
+case class CustomAuth(token: String)
+
+def decodeAuth(s: String): DecodeResult[CustomAuth] = {
+  val TokenPattern = "Token token=(.+)".r
+  s match {
+    case TokenPattern(token) => DecodeResult.Value(CustomAuth(token))
+    case _                   => DecodeResult.Error(s, new Exception("token not found"))
+  }
+}
+
+def encodeAuth(auth: CustomAuth): String = auth.token
+
+implicit val authCodec: PlainCodec[CustomAuth] = Codec.stringPlainCodecUtf8
+  .mapDecode(decodeAuth)(encodeAuth)
+```
+
+The user will find the decoded token as the last argument of the method in the trait.
+
+```scala
+@command //translate this to a POST
+def doSomethingWithTheCat(catId: Int, token: AuthToken): F[Either[Error, Unit]]
+```

docs/tapiro/migrate.md

@@ -0,0 +1,42 @@
+---
+id: migrate
+title: Migration from Wiro
+---
+
+Tapiro is meant to deprecate [wiro](https://github.com/buildo/wiro).
+
+Tapiro is based on the same concepts of wiro, the migration is pretty straightforward.
+
+Here is a checklist of what you need to do:
+1. Install the plugin (as described in the [guide](installation.md))
+2. Configure your `build.sbt` (as described in the [guide](installation.md))
+3. Add `AuthToken` type parameter to controllers
+    `trait AccountController[F]` -> `trait AccountController[F[_], AuthToken]`
+4. Modify controllers so that wiro `Auth` is replaced with AuthToken and move as last argument
+    `def read(token: Auth, arg: Int)` -> `def read(arg: Int, token: AuthToken)`
+5. Add `**/*Endpoints.scala linguist-generated` to repository's `.gitattributes` to automatically collapse tapiro generated code in GitHub diffs
+6. Add required codecs
+This is a valid codec for wiro.Auth:
+
+```scala mdoc
+import sttp.tapir._
+import sttp.tapir.Codec._
+
+case class Auth(token: String) //should be imported as wiro.Auth instead
+
+implicit val authCodec: PlainCodec[Auth] = Codec.stringPlainCodecUtf8
+  .mapDecode(decodeAuth)(encodeAuth)
+
+def decodeAuth(s: String): DecodeResult[Auth] = {
+  val TokenPattern = "Token token=(.+)".r
+  s match {
+    case TokenPattern(token) => DecodeResult.Value(Auth(token))
+    case _                   => DecodeResult.Error(s, new Exception("token not found"))
+  }
+}
+
+def encodeAuth(auth: Auth): String = auth.token
+```
+7. Run `sbt tapiro`
+
+Using `Server.AkkaHttp` the resulting routes can be added to wiro as custom routes.

docs/tapiro/rpc.md

@@ -0,0 +1,6 @@
+---
+id: rpc
+title: Why?
+---
+
+> 📖 **NOTE**: Long time ago we wrote a [blogpost](https://blog.buildo.io/http-routes-at-buildo-1424250c41d3) about this. The blogpost is about [another library](https://github.com/buildo/wiro) but the underlying concepts are the same.

project/Dependencies.scala

@@ -37,6 +37,7 @@ object Dependencies {
     val plantuml = "8059"
     val pprint = "0.5.9"
     val sbtLogging = "1.3.3"
+    val tapir = "0.12.19"
   }
 
   val circeCore = "io.circe" %% "circe-core" % V.circe
@@ -80,6 +81,10 @@ object Dependencies {
   val plantuml = "net.sourceforge.plantuml" % "plantuml" % V.plantuml
   val pprint = "com.lihaoyi" %% "pprint" % V.pprint
   val sbtLogging = "org.scala-sbt" %% "util-logging" % V.sbtLogging
+  val tapir = "com.softwaremill.sttp.tapir" %% "tapir-core" % V.tapir
+  val tapirJsonCirce = "com.softwaremill.sttp.tapir" %% "tapir-json-circe" % V.tapir
+  val tapirCore = "com.softwaremill.sttp.tapir" %% "tapir-core" % V.tapir
+  val tapirHttp4s = "com.softwaremill.sttp.tapir" %% "tapir-http4s-server" % V.tapir
 
   val enumeroDependencies = List(
     scalatest,
@@ -191,6 +196,10 @@ object Dependencies {
 
   val docsDependencies = List(
     plantuml,
+    tapir,
+    tapirJsonCirce,
+    tapirCore,
+    tapirHttp4s
   )
 
 }

website/i18n/en.json

@@ -49,6 +49,7 @@
       "toctoc": "toctoc",
       "enumero": "enumero",
       "sbt-buildo": "sbt-buildo",
+      "tapiro": "tapiro",
       "GitHub": "GitHub"
     },
     "categories": {

website/sidebars.json

@@ -14,6 +14,14 @@
   "enumero": {
     "Getting started": ["enumero/introduction", "enumero/installation"]
   },
+  "tapiro": {
+    "Setup": ["tapiro/installation"],
+    "Getting started": [
+      "tapiro/introduction",
+      "tapiro/rpc",
+      "tapiro/migrate"
+    ]
+  },
   "sbt-buildo": {
     "Getting started": ["sbt-buildo/introduction"]
   },

website/siteConfig.js

@@ -29,6 +29,7 @@ const siteConfig = {
     { doc: "toctoc/installation", label: "toctoc" },
     { doc: "enumero/introduction", label: "enumero" },
     { doc: "sbt-buildo/introduction", label: "sbt-buildo" },
+    { doc: "tapiro/introduction", label: "tapiro" },
     { search: true },
     { href: "https://github.com/buildo/retro", label: "GitHub", external: true }
   ],