cargo-binstall/crates/binstalk-manifests/src/cargo_config.rs

//! Cargo's `.cargo/config.toml`
//!
//! This manifest is used by Cargo to load configurations stored by users.
//!
//! Binstall reads from them to be compatible with `cargo-install`'s behavior.

use std::{
    borrow::Cow,
    collections::BTreeMap,
    fs::File,
    io,
    path::{Path, PathBuf},
};

use compact_str::CompactString;
use fs_lock::FileLock;
use home::cargo_home;
use miette::Diagnostic;
use serde::Deserialize;
use thiserror::Error;

#[derive(Debug, Deserialize)]
pub struct Install {
    /// `cargo install` destination directory
    pub root: Option<PathBuf>,
}

#[derive(Debug, Deserialize)]
pub struct Http {
    /// HTTP proxy in libcurl format: "host:port"
    ///
    /// env: CARGO_HTTP_PROXY or HTTPS_PROXY or https_proxy or http_proxy
    pub proxy: Option<CompactString>,
    /// timeout for each HTTP request, in seconds
    ///
    /// env: CARGO_HTTP_TIMEOUT or HTTP_TIMEOUT
    pub timeout: Option<u64>,
    /// path to Certificate Authority (CA) bundle
    pub cainfo: Option<PathBuf>,
}

#[derive(Eq, PartialEq, Debug, Deserialize)]
#[serde(untagged)]
pub enum Env {
    Value(CompactString),
    WithOptions {
        value: CompactString,
        force: Option<bool>,
        relative: Option<bool>,
    },
}

#[derive(Debug, Deserialize)]
pub struct Registry {
    pub index: Option<CompactString>,
}

#[derive(Debug, Deserialize)]
pub struct DefaultRegistry {
    pub default: Option<CompactString>,
}

#[derive(Debug, Default, Deserialize)]
pub struct Config {
    pub install: Option<Install>,
    pub http: Option<Http>,
    pub env: Option<BTreeMap<CompactString, Env>>,
    pub registries: Option<BTreeMap<CompactString, Registry>>,
    pub registry: Option<DefaultRegistry>,
}

fn join_if_relative(path: Option<&mut PathBuf>, dir: &Path) {
    match path {
        Some(path) if path.is_relative() => *path = dir.join(&path),
        _ => (),
    }
}

impl Config {
    pub fn default_path() -> Result<PathBuf, ConfigLoadError> {
        Ok(cargo_home()?.join("config.toml"))
    }

    pub fn load() -> Result<Self, ConfigLoadError> {
        Self::load_from_path(Self::default_path()?)
    }

    /// * `dir` - path to the dir where the config.toml is located.
    ///           For relative path in the config, `Config::load_from_reader`
    ///           will join the `dir` and the relative path to form the final
    ///           path.
    pub fn load_from_reader<R: io::Read>(
        mut reader: R,
        dir: &Path,
    ) -> Result<Self, ConfigLoadError> {
        fn inner(reader: &mut dyn io::Read, dir: &Path) -> Result<Config, ConfigLoadError> {
            let mut vec = Vec::new();
            reader.read_to_end(&mut vec)?;

            if vec.is_empty() {
                Ok(Default::default())
            } else {
                let mut config: Config = toml_edit::de::from_slice(&vec)?;
                join_if_relative(
                    config
                        .install
                        .as_mut()
                        .and_then(|install| install.root.as_mut()),
                    dir,
                );
                join_if_relative(
                    config.http.as_mut().and_then(|http| http.cainfo.as_mut()),
                    dir,
                );
                if let Some(envs) = config.env.as_mut() {
                    for env in envs.values_mut() {
                        if let Env::WithOptions {
                            value,
                            relative: Some(true),
                            ..
                        } = env
                        {
                            let path = Cow::Borrowed(Path::new(&value));
                            if path.is_relative() {
                                *value = dir.join(&path).to_string_lossy().into();
                            }
                        }
                    }
                }
                Ok(config)
            }
        }

        inner(&mut reader, dir)
    }

    pub fn load_from_path(path: impl AsRef<Path>) -> Result<Self, ConfigLoadError> {
        fn inner(path: &Path) -> Result<Config, ConfigLoadError> {
            match File::open(path) {
                Ok(file) => {
                    let file = FileLock::new_shared(file)?;
                    // Any regular file must have a parent dir
                    Config::load_from_reader(file, path.parent().unwrap())
                }
                Err(err) if err.kind() == io::ErrorKind::NotFound => Ok(Default::default()),
                Err(err) => Err(err.into()),
            }
        }

        inner(path.as_ref())
    }
}

#[derive(Debug, Diagnostic, Error)]
#[non_exhaustive]
pub enum ConfigLoadError {
    #[error("I/O Error: {0}")]
    Io(#[from] io::Error),

    #[error("Failed to deserialize toml: {0}")]
    TomlParse(Box<toml_edit::de::Error>),
}

impl From<toml_edit::de::Error> for ConfigLoadError {
    fn from(e: toml_edit::de::Error) -> Self {
        ConfigLoadError::TomlParse(Box::new(e))
    }
}

impl From<toml_edit::TomlError> for ConfigLoadError {
    fn from(e: toml_edit::TomlError) -> Self {
        ConfigLoadError::TomlParse(Box::new(e.into()))
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    use std::{io::Cursor, path::MAIN_SEPARATOR};

    use compact_str::format_compact;

    const CONFIG: &str = r#"
[env]
# Set ENV_VAR_NAME=value for any process run by Cargo
ENV_VAR_NAME = "value"
# Set even if already present in environment
ENV_VAR_NAME_2 = { value = "value", force = true }
# Value is relative to .cargo directory containing `config.toml`, make absolute
ENV_VAR_NAME_3 = { value = "relative-path", relative = true }

[http]
debug = false               # HTTP debugging
proxy = "host:port"         # HTTP proxy in libcurl format
timeout = 30                # timeout for each HTTP request, in seconds
cainfo = "cert.pem"         # path to Certificate Authority (CA) bundle

[install]
root = "/some/path"         # `cargo install` destination directory
    "#;

    #[test]
    fn test_loading() {
        let config = Config::load_from_reader(Cursor::new(&CONFIG), Path::new("root")).unwrap();

        assert_eq!(
            config.install.unwrap().root.as_deref().unwrap(),
            Path::new("/some/path")
        );

        let http = config.http.unwrap();
        assert_eq!(http.proxy.unwrap(), CompactString::new_inline("host:port"));
        assert_eq!(http.timeout.unwrap(), 30);
        assert_eq!(http.cainfo.unwrap(), Path::new("root").join("cert.pem"));

        let env = config.env.unwrap();
        assert_eq!(env.len(), 3);
        assert_eq!(
            env.get("ENV_VAR_NAME").unwrap(),
            &Env::Value(CompactString::new("value"))
        );
        assert_eq!(
            env.get("ENV_VAR_NAME_2").unwrap(),
            &Env::WithOptions {
                value: CompactString::new("value"),
                force: Some(true),
                relative: None,
            }
        );
        assert_eq!(
            env.get("ENV_VAR_NAME_3").unwrap(),
            &Env::WithOptions {
                value: format_compact!("root{MAIN_SEPARATOR}relative-path"),
                force: None,
                relative: Some(true),
            }
        );
    }
}