topcoat-cli 0.5.0

use std::path::{Path, PathBuf};
use std::process::Stdio;

use tokio::process::Command;

/// The output of `cargo metadata` for the current workspace.
pub struct Metadata(serde_json::Value);

impl Metadata {
    /// Query the workspace's own metadata (`cargo metadata --no-deps`).
    /// Returns `None` when cargo cannot be spawned or reports an error.
    pub async fn workspace() -> Option<Self> {
        Self::run(&["--no-deps"]).await
    }

    /// Query metadata with the dependency graph resolved, so the output also
    /// lists path dependencies living outside the workspace. Returns `None`
    /// when cargo cannot be spawned or reports an error.
    pub async fn full() -> Option<Self> {
        Self::run(&[]).await
    }

    async fn run(extra_args: &[&str]) -> Option<Self> {
        let output = Command::new("cargo")
            .args(["metadata", "--format-version=1"])
            .args(extra_args)
            .stdout(Stdio::piped())
            .stderr(Stdio::inherit())
            .spawn()
            .ok()?
            .wait_with_output()
            .await
            .ok()?;

        if !output.status.success() {
            return None;
        }

        serde_json::from_slice(&output.stdout).ok().map(Self)
    }

    /// The workspace's cargo target directory.
    pub fn target_dir(&self) -> Option<PathBuf> {
        self.0["target_directory"].as_str().map(PathBuf::from)
    }

    /// The workspace root directory, which holds the root manifest and
    /// lockfile; in a virtual workspace it is not a package of its own.
    pub fn workspace_root(&self) -> Option<PathBuf> {
        self.0["workspace_root"].as_str().map(PathBuf::from)
    }

    /// The manifest directory of every local package: a package without a
    /// `source` is local -- a workspace member or a path dependency, wherever
    /// it lives on disk.
    pub fn local_package_dirs(&self) -> Vec<PathBuf> {
        self.0["packages"]
            .as_array()
            .into_iter()
            .flatten()
            .filter(|package| package["source"].is_null())
            .filter_map(|package| {
                let manifest = Path::new(package["manifest_path"].as_str()?);
                Some(manifest.parent()?.to_path_buf())
            })
            .collect()
    }
}