Struct InstanceBuilder

pub struct InstanceBuilder { /* private fields */ }

InstanceBuilder offers the creation of configured instances. Due to this pattern, you can for example use dependency injection in your tests without exposing those.

The object to be build implements the FromInstanceBuilder trait in its module.

use std::convert::Infallible;
use ::instancebuilder::{BuilderError, InstanceBuilder, FromInstanceBuilder};

struct TestImplementation {
    inner: String,
}

struct TestConfig {
    key: String,
}

impl FromInstanceBuilder for TestImplementation {
    fn try_from_builder(builder: &InstanceBuilder) -> Result<Self, BuilderError> {
        let config: &TestConfig = builder.data()?;
        Ok(Self {
            inner: config.key.clone(),
        })
    }
}

let config = TestConfig {
   key: String::from("help me!"),
};

let mut  builder = InstanceBuilder::new();
builder.insert(config);

let instance = builder.build::<TestImplementation>().unwrap();

Implementations

impl InstanceBuilder

pub fn new() -> Self

pub fn insert<D: Any + Send + Sync>(&mut self, data: D)

pub fn data<D: Any + Send + Sync>(&self) -> Result<&D, BuilderError>

pub fn data_opt<D: Any + Send + Sync>(&self) -> Option<&D>

pub fn build<T>(&self) -> Result<T, BuilderError>

where T: FromInstanceBuilder,

Trait Implementations

impl Default for InstanceBuilder

fn default() -> Self

Returns the “default value” for a type.