Function libherokubuildpack::error::on_error

pub fn on_error<F, E>(f: F, error: Error<E>)
where
    E: Debug,
    F: Fn(E),

Handles a given libcnb::Error in a consistent style.

This function is intended to be used inside libcnb::Buildpack::on_error.

It outputs generic libcnb errors in a consistent style using the logging functions from this crate. Buildpack specific errors are handled by the passed custom handler.

Example:

use libcnb::build::{BuildContext, BuildResult};
use libcnb::Buildpack;
use libcnb::detect::{DetectContext, DetectResult};
use libcnb::generic::{GenericMetadata, GenericPlatform};
use libherokubuildpack::log::log_error;
use libherokubuildpack::error::on_error;

#[derive(Debug)]
enum FooBuildpackError {
    CannotExecuteFooBuildTool(std::io::Error),
    InvalidFooDescriptorToml
}

fn on_foo_buildpack_error(e: FooBuildpackError) {
    match e {
        FooBuildpackError::InvalidFooDescriptorToml => {
            log_error("Invalid foo.toml", "Your app's foo.toml is invalid!");
        }
        FooBuildpackError::CannotExecuteFooBuildTool(inner) => {
            log_error("Couldn't execute foo build tool", format!("Cause: {}", &inner));
        }
    }
}

struct FooBuildpack;

impl Buildpack for FooBuildpack {
    type Platform = GenericPlatform;
    type Metadata = GenericMetadata;
    type Error = FooBuildpackError;

    // Omitted detect and build implementations...

    fn on_error(&self, error: libcnb::Error<Self::Error>) {
        on_error(on_foo_buildpack_error, error)
    }
}