util

This library is available on Maven Central and on our public Bintray repository, found at: https://dl.bintray.com/outworkers/oss-releases/.

It is publicly available, for both Scala 2.10.x and Scala 2.11.x. Check the badges at the top of this README for the latest version of util available. The badges are automatically updated when a new version is out, this readme is not.

Table of contents

• Integrating the util library
• Parsers
  • Optional parsers
  • Applicative parsers
• Testing
  • Automated data sampling
• Contributors
• Copyright

Integrating the util library

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The util library is designed to wrap common functionality in all our frameworks and offer it at the convenience of a dependency. Anything that will be useful long term to a great number of people belongs in these modules, to avoid duplication and help make our devs aware they can simply use what already exists.

The full list of available modules is:

libraryDependencies ++= Seq(
  "com.outworkers" %% "util-lift" % Versions.util,
  "com.outworkers" %% "util-domain" % Versions.util,
  "com.outworkers" %% "util-parsers" % Versions.util,
  "com.outworkers" %% "util-parsers-cats" % Versions.util,
  "com.outworkers" %% "util-validators" % Versions.util,
  "com.outworkers" %% "util-validators-cats" % Versions.util,
  "com.outworkers" %% "util-play" % Versions.util,
  "com.outworkers" %% "util-urls" % Versions.util,
  "com.outworkers" %% "util-testing" % Versions.util
)

util-testing

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The testing module features the AsyncAssertionsHelper, which builds on top of ScalaTest to offer simple asynchronous assertions. We use this pattern heavily throughout the Outworkers ecosystem of projects, from internal to DSL modules and so forth. Asynchronous testing generally offers a considerable performance gain in code.

Summary:

• The dependency you need is "com.outworkers" %% "util-testing" % UtilVersion.
• You have to import com.outworkers.util.testing._.
• You have three main assertion methods, successful, failing, and failingWith.
• You can configure the timeout of waiters with implicit val timeout: PatienceConfiguration.Timeout = timeout(20 seconds).
• The default timeout value is 1 second.

util-parsers

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The parser module features an easy to use and integrate set of ScalaZ Applicative based parsers, with an Option based parser variant. It allows us to seamlessly deal with validation chains at REST API level or whenever validation is involved. Whether it’s monadic composition of options or chaining of applicative functors to obtain a “correct” chain, the parser module is designed to offer an all-you-can-eat buffet of mini parsers that can be easily composed to suit any validation needs.

Each parser comes in three distinct flavours, a ValidationNel parser that parsers the end type from a String and returns the type itself, a parser that parses an end result from an Option[String] and parserOpt variant that returns an Option[T] instead of a ValidationNel[String, T], which allows for Monadic composition, where you need to “short-circuit” evaluation and validation, instead of computing the full chain by chaining applicatives.

Option parsers

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The full list of optional parsers is:

Type	Input type	Parser Output type
Int	String|Option[String]	ValidationNel[String, Int]
Long	String|Option[String]	ValidationNel[String, Long]
Double	String|Option[String]	ValidationNel[String, Double]
Float	String|Option[String]	ValidationNel[String, Float]
UUID	String|Option[String]	ValidationNel[String, UUID]
Email	String|Option[String]	ValidationNel[String, String]
DateTime	String|Option[String]	ValidationNel[String, org.joda.time.DateTime]

Option parsers are designed for chains where you want to short-circuit and exit to result as soon a parser fails. This short-circuit behaviour is the default flatMap behaviour of an Option, as soon as an Option is None the chain breaks. Unlike applicatives, the evaluation sequence of options will be escaped and you cannot for instance return an error for every parser that couldn’t validate. Instead, you will only get the first error in the sequence.

An example of how to use Option parsers might be:

import com.outworkers.util.parsers._
import com.outworkers.util.samplers._

object Test {
  def optionalParsing(email: String, age: String): Option[String] = {
    for {
      validEmail <- parseOpt[EmailAddress](email)
      validAge <- parseOpt[Int](age)
    } yield s"This person can be reached at $validEmail and is $validAge years old"
  }
}

Applicative parsers

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The full list of ScalaZ Validation based applicative parsers is:

Type	Input type	Parser Output type
Int	String|Option[String]	ValidationNel[String, Int]
Long	String|Option[String]	ValidationNel[String, Long]
Double	String|Option[String]	ValidationNel[String, Double]
Float	String|Option[String]	ValidationNel[String, Float]
UUID	String|Option[String]	ValidationNel[String, UUID]
Email	String|Option[String]	ValidationNel[String, String]
DateTime	String|Option[String]	ValidationNel[String, org.joda.time.DateTime]

To illustrate the basic usage of applicative parsers and how to chain them, have a look below.

import scalaz._
import scalaz.Scalaz._
import com.outworkers.util.parsers._

case class UserToRegister(
  email: String,
  age: Int
)

object Test {
  
  def registerUser(str: String, age: String):  Validation[NonEmptyList[String], UserToRegister] = {
    (parse[EmailAddress](str) |@| parse[Int](age)) {
      (validEmail, validAge) => UserToRegister(validEmail.value, validAge)
    }
  }
  
}

Contributors

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• Flavian Alexandru @alexflav23
• Jens Halm @jenshalm
• Bartosz Jankiewicz @bjankie1

Copyright

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Copyright (c) 2014 - 2016 outworkers.

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