Function load_metadata

crates/cargo-lambda-metadata/src/cargo/mod.rs:201–238

(
    manifest_path: P,
    target_dir: Option<&Path>,
)

/// Create metadata about the root package in the Cargo manifest, without any dependencies.
#[tracing::instrument(target = "cargo_lambda")]
pub fn load_metadata<P: AsRef<Path> + Debug>(
    manifest_path: P,
    target_dir: Option<&Path>,
) -> Result<CargoMetadata, MetadataError> {
    trace!("loading Cargo metadata");
    let mut metadata_cmd = cargo_metadata::MetadataCommand::new();
    metadata_cmd
        .no_deps()
        .verbose(enabled!(target: "cargo_lambda", Level::TRACE));

    // If target-dir was explicitly specified, pass it to cargo metadata
    if let Some(dir) = target_dir {
        metadata_cmd.other_options(vec![format!("--target-dir={}", dir.display())]);
    }

    // try to split manifest path and assign current_dir to enable parsing a project-specific
    // cargo config
    let manifest_ref = manifest_path.as_ref();

    match (manifest_ref.parent(), manifest_ref.file_name()) {
        (Some(project), Some(manifest)) if is_project_metadata_ok(project) => {
            metadata_cmd.current_dir(project);
            metadata_cmd.manifest_path(manifest);
        }
        _ => {
            // fall back to using the manifest_path without changing the dir
            // this means there will not be any project-specific config parsing
            metadata_cmd.manifest_path(manifest_ref);
        }
    }

    trace!(metadata = ?metadata_cmd, "loading cargo metadata");
    let meta = metadata_cmd
        .exec()
        .map_err(MetadataError::FailedCmdExecution)?;
    trace!(metadata = ?meta, "loaded cargo metadata");
    Ok(meta)
}

/// Load the main binary in the project.
/// It returns an error if the project includes from than one binary.