----

-title: "Automatic High Quality Releases"

-date: 2012-11-13T21:31:00Z

-comments: true

-tags: ["shell scripting", "finatra"]

----

-

-Recently, I invested some time into automating some of the work that goes into a [Finatra](http://github.com/capotej/finatra#readme) release.

-

-<!--more-->

-

-The work consists of updating:

-

-* The version in the XML fragment of the main [README.markdown](https://github.com/finatra/https://github.com/capotej/finatra/blob/master/README.markdown)

-

-* The version in the [pom.xml](https://github.com/capotej/finatra-example/blob/master/pom.xml) of the [example app](http://github.com/capotej/finatra-example)

-

-* Any API changes in the [example app](http://github.com/capotej/finatra-example)

-

-* The version in the template pom.xml of the app generator

-

-* The generated unit test of the app generator that demonstrates testing any new API features

-

-* Any API changes inside the app template of the app generator

-

-Using [sub](https://github.com/37signals/sub#readme), I was able to create a `finatra` [command](https://github.com/capotej/finatra/tree/master/script/finatra) that automated all of the above based on a single template, which also happens to be the [main unit test](https://github.com/capotej/finatra/blob/master/src/test/scala/com/twitter/finatra/ExampleSpec.scala). This ensures that the README, the example app, and the app generator never fall out of sync with the frameworks API.

-

-

-Last week we released [1.1.0](https://github.com/capotej/finatra/commit/37c81957271dde77d4c3f6361bbae705a5142c89), and the README was [completely generated](https://github.com/capotej/finatra/commit/913d0ed5bfa18c903feb5779d4d8b9d87703b6c5), as was the [example app](https://github.com/capotej/finatra-example/commit/dbc82908360f3cb4cfc4388c28f593f17258fab2). Not to mention, all generated apps would also contain the latest templates and examples!

-

-

-

-Let's dive into how it all works:

-

-## The source of truth

-

-I annotated our main unit test with special tokens, like so:

-

-```scala ExampleAppSpec.scala

-class ExampleSpec extends SpecHelper {

-

- /* ###BEGIN_APP### */

-

- class ExampleApp extends Controller {

-

- /**

- * Basic Example

- *

- * curl http://localhost:7070/hello => "hello world"

- */

- get("/") { request =>

- render.plain("hello world").toFuture

- }

-

- }

-

- val app = new ExampleApp

-

- /* ###END_APP### */

-

-

- /* ###BEGIN_SPEC### */

-

- "GET /hello" should "respond with hello world" in {

- get("/")

- response.body should equal ("hello world")

- }

-

- /* ###END_SPEC### */

-}

-```

-

-Using the special `/* ### */` comments, the main app and its test can be extracted from the code of our test.

-

-## The app generator

-

-Now that we have our "template", we can build our app generator to use it. I customized [base](http://capotej.com/blog/2012/11/01/base-a-scala-project-generator/) and ended up with: [script/finatra/libexec/finatra-new](https://github.com/capotej/finatra/blob/master/script/finatra/libexec/finatra-new)

-

-You can then run:

-

-```sh

-$ ./finatra new com.example.myapp

-```

-

-and it will generate ```myapp/``` based on the tested example code from the test suite above.

-

-## The example app

-

-The [example app](https://github.com/capotej/finatra-example#readme) is just a generated app using the latest app generator:

-

-```sh

-

-#!/bin/bash

-# Usage: finatra update-example

-# Summary: generates the example app from the template

-

-set -e

-

-source $_FINATRA_ROOT/lib/base.sh

-

-tmpdir=$(mktemp -d /tmp/finatra_example.XXX)

-

-$_FINATRA_ROOT/bin/finatra new com.twitter.finatra_example $tmpdir

-

-cp -Rv $tmpdir/finatra_example/ $EXAMPLE_REPO

-

-rm -rf $tmpdir

-

-cd $EXAMPLE_REPO && mvn test

-

-```

-

-This also tests the app generator and the generated app!

-

-## Updating the README

-

-Lastly, there's a [command](https://github.com/capotej/finatra/blob/master/script/finatra/libexec/finatra-update-readme) for updating the README with the new example and version number.