https://github.com/tvinke/bulletproof
Groovy AST transformations, such as @ValueObject and @NonNull, which makes constructing an instance more bullet-proof.
https://github.com/tvinke/bulletproof
ast groovy groovy-language lombok
Last synced: 2 months ago
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Groovy AST transformations, such as @ValueObject and @NonNull, which makes constructing an instance more bullet-proof.
- Host: GitHub
- URL: https://github.com/tvinke/bulletproof
- Owner: tvinke
- License: apache-2.0
- Created: 2017-05-31T14:35:59.000Z (almost 9 years ago)
- Default Branch: master
- Last Pushed: 2017-09-08T08:06:34.000Z (over 8 years ago)
- Last Synced: 2023-08-05T20:51:26.507Z (over 2 years ago)
- Topics: ast, groovy, groovy-language, lombok
- Language: Groovy
- Homepage:
- Size: 216 KB
- Stars: 11
- Watchers: 2
- Forks: 1
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
[](https://travis-ci.org/tvinke/bulletproof)
[](http://repo1.maven.org/maven2/com/github/tvinke/bulletproof/0.2/bulletproof-0.2.jar)
[](https://github.com/tvinke/bulletproof/releases/tag/v0.2)
# Bulletproof
*Groovy AST transformations, such as @ValueObject and @NonNull, which makes constructing an instance more bullet-proof.*
Groovy has the `Immutable` annotation which allows to create immutable classes, which is a prerequisite for creating [value objects](https://en.wikipedia.org/wiki/Value_object). Unfortunately, when a class has been annotated with `Immutable` it's no longer possible to add your own constructor to verify if provided parameters are not `null`, making our value objects really bullet-proof.
*See [Ted Vinke Blog: Make Your Groovy Objects More Bullet-Proof](https://tedvinke.wordpress.com/2017/08/30/make-your-groovy-objects-more-bullet-proof/)*
Bulletproof helps to fill this gap by adding a few AST transformations.
* The `NonNull` annotation which modifies every constructor to perform null-checks. Add this to an `Immutable` class and no `null` slips past your constructor.
* The `ValueObject` meta-annotation which puts both `NonNull` and `Immutable` on your class as a convenience to do above step with one annotation.
## Contents
* [Prerequisites](#prerequisites)
* [Installation](#installation)
* [Annotations](#annotations)
* [@NonNull](#nonnull)
* [@ValueObject](#value-object)
* [Future Changes](#future-changes)
## Prerequisites
Bulletproof requires Java 7 or later.
## Installation
Add the bulletproof jar to the classpath in your preferred way and you're set.
### Grape
```groovy
@Grab('com.github.tvinke:bulletproof:0.2')
```
### Gradle
```groovy
compile group: 'com.github.tvinke', name: 'bulletproof', version: '0.2'
```
### Maven
```xml
com.github.tvinke
bulletproof
0.2
```
## Annotations
Consult the [bulletproof 0.2 Groovydocs](http://tvinke.github.io/bulletproof/v0.2/groovydoc/) for complete API information.
### NonNull
The `NonNull` annotation on the class-level triggers an AST transformation which modifies every constructor to perform a null-check.
```groovy
@groovy.transform.Immutable
@tvinke.bulletproof.transform.NonNull
class Person {
String name
}
new Person() // throws IllegalArgumentException: "Name can not be null"
```
### Value Object
The `ValueObject` meta-annotation combines the `Immutable` and `NonNull` annotations, which is used to assist in the creation of [value objects](https://en.wikipedia.org/wiki/Value_object).
```groovy
@tvinke.bulletproof.transform.ValueObject
class Money {
BigDecimal amount
}
new Money(amount: null) // throws IllegalArgumentException because of NonNull
def money = new Money(2.95)
money.amount = 3.0 // throws ReadOnlyPropertyException because of Immutable
```
## Future Changes
* Consider allowing a _mutable_ object (e.g. default Map constructor, or with `TupleConstructor`) also to have null-checks performed. In this case probably also through the setters.
* In above case, then probably you need you want to specify which properties need to be null-checked instead of just everything.