xpepper

When you find it difficult to write a concise, focused, isolated test, the production code has unhealthy dependencies to loosen, invert, or break.

Here, “concise” means having no irrelevant details; “focused” means failing for only one reason; “isolated” means executing without side effects on other tests.

(https://thecodewhisperer-blog.tumblr.com/post/333781027/what-your-tests-dont-need-to-know-will-hurt-you)

xpepper

Before to start

In JavaScript there is NO concept of Class.

Everything is an Object.

Inheritance between objects is achieved with a mechanism known as Prototypal Inheritance.

We can create Objects and then link them together OLOO (Objects-Linked-to-Other-Objects).

xpepper

// it's NOT an extension function
// it takes the receiver and a lambda with the same receiver
// it returns the result of the lambda on the implicit receiver
inline fun <T, R> with(receiver: T, block: T.() -> R): R {
    return receiver.block()
}

with ("ciao") {
    length + 1

xpepper

Write the simplest Kotlin file, and name it Main.kt:

fun main(args: Array<String>) {
    println("Hello world!")
}

Then compile the Kotlin file with kotlinc, which runs the Kotlin compiler

xpepper

Keeping a branch up-to-date with master and then merge back the branch to master

git checkout new-feature # Go to the feature branch named "new-feature"
git rebase master

# Now your feature have all the commits from master!

xpepper

Watching my train delay :-|

My train number is 2134, and its id is S07113 (to find that id, you've to inspect the page http://www.viaggiatreno.it/viaggiatrenonew/index.jsp with a network console).

~ watch -d -n 60 http "http://www.viaggiatreno.it/viaggiatrenonew/resteasy/viaggiatreno/andamentoTreno/S07113/2134 | jq '.ritardo'"

PS the FS frontend is http://www.viaggiatreno.it/viaggiatrenonew/index.jsp

requirements

xpepper

To have my Java8 app be able to be executed on a JVM Java11 I had to add this dependency to my build.gradle:

...
implementation 'org.glassfish.jaxb:jaxb-runtime'
...

Otherwise I got a runtime exception: java.lang.ClassNotFoundException: javax.xml.bind.JAXBContext

xpepper

brew java formula	output
brew cask info java8	java8: 8u202
brew cask info adoptopenjdk/openjdk/adoptopenjdk8	adoptopenjdk8: 8,212:b03
brew cask info zulu8	zulu8: 8.0.212,8.38.0.13-ca
brew cask info corretto8	corretto8: 8.212.04.2
brew cask info java11	java11: 11.0.2,9

xpepper

class ReceiptText(private val template: String) : (Int) -> String {
    override fun invoke(price: Int): String {
        return template.replace("%%%", price.toString())
    }
}

val receiptText = ReceiptText("The total price to pay is %%% euro")
println(receiptText(10))

xpepper

David Heinemeier Hansson is the co-founder and CTO of Basecamp, a project management and team communication software designed to help teams work together calmly and productively.

David Heinemeier Hansson is the co-founder and CTO of Basecamp. He's the creator of the web application framework Ruby on Rails and has co-authored several books about remote work and the future of work, including REMOTE: Office Not Required and It Doesn't Have to Be Crazy at Work. In this interview, he speaks with Owl Labs about the future of work, why remote work will evolve to become the way business is done, and why ambition can be a weakness for some entrepreneurs, instead of a strength.

Owl Labs (OL): For those of our readers who aren't already familiar with your career, you created the web application framework Ruby on Rails, you're co-founder and CTO of Basecamp, and you've published several best-selling books, the most recent of which was It Doesn't Have to be Crazy at Work. My first question is, do you sleep? My second,