Ecosyste.ms: Awesome
An open API service indexing awesome lists of open source software.
https://github.com/justeattakeaway/genything
Generate Anything
https://github.com/justeattakeaway/genything
faking ios mocking stubbing swift testing
Last synced: 3 days ago
JSON representation
Generate Anything
- Host: GitHub
- URL: https://github.com/justeattakeaway/genything
- Owner: justeattakeaway
- License: apache-2.0
- Created: 2021-11-16T19:43:28.000Z (almost 3 years ago)
- Default Branch: main
- Last Pushed: 2023-06-15T18:01:20.000Z (over 1 year ago)
- Last Synced: 2024-11-06T06:41:28.349Z (8 days ago)
- Topics: faking, ios, mocking, stubbing, swift, testing
- Language: Swift
- Homepage: https://justeattakeaway.github.io/Genything/documentation/genything
- Size: 13.7 MB
- Stars: 28
- Watchers: 7
- Forks: 7
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Contributing: CONTRIBUTING.md
- License: LICENSE
Awesome Lists containing this project
README
Genything
## Genything - Generate Anything
Genything is a library dedicated to easy and composable generation of random data, no matter how complex.
Genything can be combined with [Trickery](#Trickery) which provides a growing library of pre-made generators which mock real-world information.
Both of these libraries may be used for code testing, rapid prototyping, demo applications, ui testing, and much more. Be creative!
- [Why use Genything?](#why-use-genything-)
* [Gen](#gen)
* [Arbitrary](#arbitrary)
- [Trickery](#trickery)
- [Examples](#examples)
- [Mixins](#mixins)
- [Installation](#installation)
* [Cocoapods](#cocoapods)
* [Swift Package Manager](#swift-package-manager)
- [Credits](#credits)
* [Contributing](#contributing)
* [Inspiration](#inspiration)
- [License](./LICENSE)
## Why use Genything?
- We do not include a dependency on XCTest
- Controllable randomness that's deterministic by default
- Produce the same results on CI, your colleagues machine, and your own
- You can use these generators for anything!
- Create dummy data for your example apps or to rapidly prototype features
- Use them in your SwiftUI previews to rapidly discover edge cases
- Run your [screenshot](https://github.com/pointfreeco/swift-snapshot-testing) [tests](https://github.com/uber/ios-snapshot-test-case) with easy-to-use and predictable data
- Use your generators to unit test with [Property Based Testing](https://medium.com/criteo-engineering/introduction-to-property-based-testing-f5236229d237)
- High test coverage
- [100% Documented](https://justeattakeaway.github.io/Genything/documentation/genything/)
### Generator
The `Generator` is the core of Genything.
```swift
public protocol Generator {
associatedtype T
func next(_ randomSource: RandomSource) -> T
}
```
It defines a type with a function capable of generating values using a `RandomSource`.
The `RandomSource` is used to track and mutate any RandomNumberGenerator instance, allowing you to control just how **much** random you would like.
A generator of bools might look like this:
```swift
struct BoolGenerator: Generator {
func next(_ randomSource: RandomSource) -> T {
Bool.random(using: &randomSource.rng)
}
}
```
or
```swift
AnyGenerator { randomSource in
Bool.random(using: &randomSource.rng)
}
```
Or, we can take advantage of Genything's arbitrary conformance for most standard Swift types (including `Bool`)
```swift
Bool.arbitrary
```
Genything provides numerous ways to [create your own Generators](https://justeattakeaway.github.io/Genything/documentation/genything/generators) under the `Generators` namespace, and the `Generator` type is [extended by many operators](https://justeattakeaway.github.io/Genything/documentation/genything/generator) which you can use to further mutate and control the resulting generator.
### Arbitrary
The `Arbitary` protocol allows a Type to define a generator suitable for generating **all** of it's values.
Take Swift's `Bool` as example, it's Arbitrary is defined as:
```swift
extension Bool: Arbitrary {
public static var arbitrary: AnyGenerator {
[true, false].arbitrary
}
}
```
We can now use this definition automatically when we are composing a more complex arbitrary type:
```swift
struct Foo {
let bar: Bool
// ...
}
extension Transaction: Arbitrary {
public static var arbitrary: AnyGenerator {
Gen.compose { generate in
Foo(
bar: generate(), // Will return true/false like a coin-flip for each generated value
//...
)
}
}
}
```
These can then be used for invariant tests, to stub an API response, as preview data, etc...
## Trickery
Genything comes together with Trickery, a collection of generators suitable for producing pseudo-realistic data according to real-world-conditions rather than those enforced only by the type.
Consider a phone number. A phone number of type `String` has rules about length, formatting, allowable characters. Whereas the arbitrary type `String` contains contains at most a definition of it's length
## GenythingTest
Genything provides two extensions for `XCTestCase` which we suggest that you use as your primary method for property testing.
- `testAll(generator:config:file:line:body)`
- `testAllSatisfy(generator:config:file:line:predicate)`
## Examples
Checkout out our [Playground guide](Example/Playground.playground)
## Mixins
Genything is happy when combined with other open source libraries!
### Generate arbitrary SFSymbols with [SFSafeSymbols](https://github.com/piknotech/SFSafeSymbols)
Generate any [SF Symbol](https://developer.apple.com/sf-symbols/)
```swift
import SFSafeSymbols
let sfSymbolGen: AnyGenerator = SFSymbol.arbitrary.map { $0.rawValue }
```
## Installation
### Cocoapods
```ruby
pod 'Genything'
pod 'Trickery' # Optional library of realistic fake data (Fake)
pod 'GenythingTest' # Optional extensions for property testing (testAll, testAllSatisfy)
```
### Swift Package Manager
Create a `Package.swift` file in your root directory and add:
```swift
dependencies: [
.package(url: "https://github.com/justeattakeaway/genything.git", .upToNextMajor(from: "1.0.0"))
]
```
Then add the packages you want to:
- General -> "Frameworks and Libraries", for an application of framework target
- Build Phases -> "Link Binary With Libraries", for a test target
## Credits
The Genything project is owned and maintained by [SkipTheDishes](https://www.skipthedishes.com/), a [Just Eat Takeaway.com](https://www.justeattakeaway.com/) subsidiary.
### Contributing
Please read the [Contribution Guide](./CONTRIBUTING.md)
### Inspiration
Genything stands on the shoulder of giants. Please check out these other libraries and resources!
- [SwiftCheck](https://github.com/typelift/SwiftCheck)
- [Fakery](https://github.com/vadymmarkov/Fakery)
- [Point-Free](https://www.pointfree.co/)'s lessons on [predictable randomness](https://github.com/pointfreeco/episode-code-samples/tree/main/0048-predictable-randomness-pt2)
- [Kotest](https://kotest.io/)'s [Property Based Testing](https://kotest.io/docs/proptest/property-based-testing.html)
## License
See: [License](./LICENSE)
Apache License Version 2.0, January 2004 http://www.apache.org/licenses/