cargo/ops/registry/

publish.rs

//! Interacts with the registry [publish API][1].
//!
//! [1]: https://doc.rust-lang.org/nightly/cargo/reference/registry-web-api.html#publish

use std::collections::BTreeMap;
use std::collections::BTreeSet;
use std::collections::HashMap;
use std::collections::HashSet;
use std::fs::File;
use std::io::Seek;
use std::io::SeekFrom;
use std::time::Duration;

use anyhow::Context as _;
use anyhow::bail;
use cargo_credential::Operation;
use cargo_credential::Secret;
use cargo_util::paths;
use crates_io::NewCrate;
use crates_io::NewCrateDependency;
use crates_io::Registry;
use itertools::Itertools;

use crate::CargoResult;
use crate::GlobalContext;
use crate::core::Dependency;
use crate::core::Package;
use crate::core::PackageId;
use crate::core::PackageIdSpecQuery;
use crate::core::SourceId;
use crate::core::Workspace;
use crate::core::dependency::DepKind;
use crate::core::manifest::ManifestMetadata;
use crate::core::resolver::CliFeatures;
use crate::ops;
use crate::ops::PackageOpts;
use crate::ops::Packages;
use crate::ops::RegistryOrIndex;
use crate::ops::registry::RegistrySourceIds;
use crate::sources::CRATES_IO_REGISTRY;
use crate::sources::RegistrySource;
use crate::sources::SourceConfigMap;
use crate::sources::source::QueryKind;
use crate::sources::source::Source;
use crate::util::Graph;
use crate::util::Progress;
use crate::util::ProgressStyle;
use crate::util::VersionExt as _;
use crate::util::auth;
use crate::util::cache_lock::CacheLockMode;
use crate::util::context::JobsConfig;
use crate::util::errors::ManifestError;
use crate::util::toml::prepare_for_publish;

use super::super::check_dep_has_version;

pub struct PublishOpts<'gctx> {
    pub gctx: &'gctx GlobalContext,
    pub token: Option<Secret<String>>,
    pub reg_or_index: Option<RegistryOrIndex>,
    pub verify: bool,
    pub allow_dirty: bool,
    pub jobs: Option<JobsConfig>,
    pub keep_going: bool,
    pub to_publish: ops::Packages,
    pub targets: Vec<String>,
    pub dry_run: bool,
    pub cli_features: CliFeatures,
}

pub fn publish(ws: &Workspace<'_>, opts: &PublishOpts<'_>) -> CargoResult<()> {
    let specs = opts.to_publish.to_package_id_specs(ws)?;

    let member_ids: Vec<_> = ws.members().map(|p| p.package_id()).collect();
    // Check that the specs match members.
    for spec in &specs {
        spec.query(member_ids.clone())?;
    }
    let mut pkgs = ws.members_with_features(&specs, &opts.cli_features)?;
    // In `members_with_features_old`, it will add "current" package (determined by the cwd)
    // So we need filter
    pkgs.retain(|(m, _)| specs.iter().any(|spec| spec.matches(m.package_id())));

    let (unpublishable, pkgs): (Vec<_>, Vec<_>) = pkgs
        .into_iter()
        .partition(|(pkg, _)| pkg.publish() == &Some(vec![]));
    // If `--workspace` is passed,
    // the intent is more like "publish all publisable packages in this workspace",
    // so skip `publish=false` packages.
    let allow_unpublishable = match &opts.to_publish {
        Packages::Default => ws.is_virtual(),
        Packages::All(_) => true,
        Packages::OptOut(_) => true,
        Packages::Packages(_) => false,
    };
    if !unpublishable.is_empty() && !allow_unpublishable {
        bail!(
            "{} cannot be published.\n\
            `package.publish` must be set to `true` or a non-empty list in Cargo.toml to publish.",
            unpublishable
                .iter()
                .map(|(pkg, _)| format!("`{}`", pkg.name()))
                .join(", "),
        );
    }

    if pkgs.is_empty() {
        if allow_unpublishable {
            let n = unpublishable.len();
            let plural = if n == 1 { "" } else { "s" };
            ws.gctx().shell().warn(format_args!(
                "nothing to publish, but found {n} unpublishable package{plural}"
            ))?;
            ws.gctx().shell().note(format_args!(
                "to publish packages, set `package.publish` to `true` or a non-empty list"
            ))?;
            return Ok(());
        } else {
            unreachable!("must have at least one publishable package");
        }
    }

    let just_pkgs: Vec<_> = pkgs.iter().map(|p| p.0).collect();
    let reg_or_index = match opts.reg_or_index.clone() {
        Some(r) => {
            validate_registry(&just_pkgs, Some(&r))?;
            Some(r)
        }
        None => {
            let reg = super::infer_registry(&just_pkgs)?;
            validate_registry(&just_pkgs, reg.as_ref())?;
            if let Some(RegistryOrIndex::Registry(registry)) = &reg {
                if registry != CRATES_IO_REGISTRY {
                    // Don't warn for crates.io.
                    opts.gctx.shell().note(&format!(
                        "found `{}` as only allowed registry. Publishing to it automatically.",
                        registry
                    ))?;
                }
            }
            reg
        }
    };

    // This is only used to confirm that we can create a token before we build the package.
    // This causes the credential provider to be called an extra time, but keeps the same order of errors.
    let source_ids = super::get_source_id(opts.gctx, reg_or_index.as_ref())?;
    let (mut registry, mut source) = super::registry(
        opts.gctx,
        &source_ids,
        opts.token.as_ref().map(Secret::as_deref),
        reg_or_index.as_ref(),
        true,
        Some(Operation::Read).filter(|_| !opts.dry_run),
    )?;

    {
        let _lock = opts
            .gctx
            .acquire_package_cache_lock(CacheLockMode::DownloadExclusive)?;

        for (pkg, _) in &pkgs {
            verify_unpublished(pkg, &mut source, &source_ids, opts.dry_run, opts.gctx)?;
            verify_dependencies(pkg, &registry, source_ids.original).map_err(|err| {
                ManifestError::new(
                    err.context(format!(
                        "failed to verify manifest at `{}`",
                        pkg.manifest_path().display()
                    )),
                    pkg.manifest_path().into(),
                )
            })?;
        }
    }

    let pkg_dep_graph = ops::cargo_package::package_with_dep_graph(
        ws,
        &PackageOpts {
            gctx: opts.gctx,
            verify: opts.verify,
            list: false,
            fmt: ops::PackageMessageFormat::Human,
            check_metadata: true,
            allow_dirty: opts.allow_dirty,
            include_lockfile: true,
            // `package_with_dep_graph` ignores this field in favor of
            // the already-resolved list of packages
            to_package: ops::Packages::Default,
            targets: opts.targets.clone(),
            jobs: opts.jobs.clone(),
            keep_going: opts.keep_going,
            cli_features: opts.cli_features.clone(),
            reg_or_index: reg_or_index.clone(),
            dry_run: opts.dry_run,
        },
        pkgs,
    )?;

    let mut plan = PublishPlan::new(&pkg_dep_graph.graph);
    // May contains packages from previous rounds as `wait_for_any_publish_confirmation` returns
    // after it confirms any packages, not all packages, requiring us to handle the rest in the next
    // iteration.
    //
    // As a side effect, any given package's "effective" timeout may be much larger.
    let mut to_confirm = BTreeSet::new();

    while !plan.is_empty() {
        // There might not be any ready package, if the previous confirmations
        // didn't unlock a new one. For example, if `c` depends on `a` and
        // `b`, and we uploaded `a` and `b` but only confirmed `a`, then on
        // the following pass through the outer loop nothing will be ready for
        // upload.
        let mut ready = plan.take_ready();
        while let Some(pkg_id) = ready.pop_first() {
            let (pkg, (_features, tarball)) = &pkg_dep_graph.packages[&pkg_id];
            opts.gctx.shell().status("Uploading", pkg.package_id())?;

            if !opts.dry_run {
                let ver = pkg.version().to_string();

                tarball.file().seek(SeekFrom::Start(0))?;
                let hash = cargo_util::Sha256::new()
                    .update_file(tarball.file())?
                    .finish_hex();
                let operation = Operation::Publish {
                    name: pkg.name().as_str(),
                    vers: &ver,
                    cksum: &hash,
                };
                registry.set_token(Some(auth::auth_token(
                    &opts.gctx,
                    &source_ids.original,
                    None,
                    operation,
                    vec![],
                    false,
                )?));
            }

            let workspace_context = || {
                let mut remaining = ready.clone();
                remaining.extend(plan.iter());
                if !remaining.is_empty() {
                    format!(
                        "\n\nnote: the following crates have not been published yet:\n  {}",
                        remaining.into_iter().join("\n  ")
                    )
                } else {
                    String::new()
                }
            };

            transmit(
                opts.gctx,
                ws,
                pkg,
                tarball.file(),
                &mut registry,
                source_ids.original,
                opts.dry_run,
                workspace_context,
            )?;
            to_confirm.insert(pkg_id);

            if !opts.dry_run {
                // Short does not include the registry name.
                let short_pkg_description = format!("{} v{}", pkg.name(), pkg.version());
                let source_description = source_ids.original.to_string();
                ws.gctx().shell().status(
                    "Uploaded",
                    format!("{short_pkg_description} to {source_description}"),
                )?;
            }
        }

        let confirmed = if opts.dry_run {
            to_confirm.clone()
        } else {
            const DEFAULT_TIMEOUT: u64 = 60;
            let timeout = if opts.gctx.cli_unstable().publish_timeout {
                let timeout: Option<u64> = opts.gctx.get("publish.timeout")?;
                timeout.unwrap_or(DEFAULT_TIMEOUT)
            } else {
                DEFAULT_TIMEOUT
            };
            if 0 < timeout {
                let source_description = source.source_id().to_string();
                let short_pkg_descriptions = package_list(to_confirm.iter().copied(), "or");
                if plan.is_empty() {
                    let report = &[
                        annotate_snippets::Group::with_title(
                        annotate_snippets::Level::NOTE
                            .secondary_title(format!(
                                "waiting for {short_pkg_descriptions} to be available at {source_description}"
                            ))),
                            annotate_snippets::Group::with_title(annotate_snippets::Level::HELP.secondary_title(format!(
                                "you may press ctrl-c to skip waiting; the {crate} should be available shortly",
                                crate = if to_confirm.len() == 1 { "crate" } else {"crates"}
                            ))),
                    ];
                    opts.gctx.shell().print_report(report, false)?;
                } else {
                    opts.gctx.shell().note(format!(
                    "waiting for {short_pkg_descriptions} to be available at {source_description}.\n\
                    {count} remaining {crate} to be published",
                    count = plan.len(),
                    crate = if plan.len() == 1 { "crate" } else {"crates"}
                ))?;
                }

                let timeout = Duration::from_secs(timeout);
                let confirmed = wait_for_any_publish_confirmation(
                    opts.gctx,
                    source_ids.original,
                    &to_confirm,
                    timeout,
                )?;
                if !confirmed.is_empty() {
                    let short_pkg_description = package_list(confirmed.iter().copied(), "and");
                    opts.gctx.shell().status(
                        "Published",
                        format!("{short_pkg_description} at {source_description}"),
                    )?;
                } else {
                    let short_pkg_descriptions = package_list(to_confirm.iter().copied(), "or");
                    opts.gctx.shell().warn(format!(
                        "timed out waiting for {short_pkg_descriptions} to be available in {source_description}",
                    ))?;
                    opts.gctx.shell().note(format!(
                        "the registry may have a backlog that is delaying making the \
                        {crate} available. The {crate} should be available soon.",
                        crate = if to_confirm.len() == 1 {
                            "crate"
                        } else {
                            "crates"
                        }
                    ))?;
                }
                confirmed
            } else {
                BTreeSet::new()
            }
        };
        if confirmed.is_empty() {
            // If nothing finished, it means we timed out while waiting for confirmation.
            // We're going to exit, but first we need to check: have we uploaded everything?
            if plan.is_empty() {
                // It's ok that we timed out, because nothing was waiting on dependencies to
                // be confirmed.
                break;
            } else {
                let failed_list = package_list(plan.iter(), "and");
                bail!(
                    "unable to publish {failed_list} due to a timeout while waiting for published dependencies to be available."
                );
            }
        }
        for id in &confirmed {
            to_confirm.remove(id);
        }
        plan.mark_confirmed(confirmed);
    }

    Ok(())
}

/// Poll the registry for any packages that are ready for use.
///
/// Returns the subset of `pkgs` that are ready for use.
/// This will be an empty set if we timed out before confirming anything.
fn wait_for_any_publish_confirmation(
    gctx: &GlobalContext,
    registry_src: SourceId,
    pkgs: &BTreeSet<PackageId>,
    timeout: Duration,
) -> CargoResult<BTreeSet<PackageId>> {
    let mut source = SourceConfigMap::empty(gctx)?.load(registry_src, &HashSet::new())?;
    // Disable the source's built-in progress bars. Repeatedly showing a bunch
    // of independent progress bars can be a little confusing. There is an
    // overall progress bar managed here.
    source.set_quiet(true);

    let now = std::time::Instant::now();
    let sleep_time = Duration::from_secs(1);
    let max = timeout.as_secs() as usize;
    let mut progress = Progress::with_style("Waiting", ProgressStyle::Ratio, gctx);
    progress.tick_now(0, max, "")?;
    let available = loop {
        {
            let _lock = gctx.acquire_package_cache_lock(CacheLockMode::DownloadExclusive)?;
            // Force re-fetching the source
            //
            // As pulling from a git source is expensive, we track when we've done it within the
            // process to only do it once, but we are one of the rare cases that needs to do it
            // multiple times
            gctx.updated_sources().remove(&source.replaced_source_id());
            source.invalidate_cache();
            let mut available = BTreeSet::new();
            for pkg in pkgs {
                if poll_one_package(registry_src, pkg, &mut source)? {
                    available.insert(*pkg);
                }
            }

            // As soon as any package is available, break this loop so we can see if another
            // one can be uploaded.
            if !available.is_empty() {
                break available;
            }
        }

        let elapsed = now.elapsed();
        if timeout < elapsed {
            break BTreeSet::new();
        }

        progress.tick_now(elapsed.as_secs() as usize, max, "")?;
        std::thread::sleep(sleep_time);
    };

    Ok(available)
}

fn poll_one_package(
    registry_src: SourceId,
    pkg_id: &PackageId,
    source: &mut dyn Source,
) -> CargoResult<bool> {
    let version_req = format!("={}", pkg_id.version());
    let query = Dependency::parse(pkg_id.name(), Some(&version_req), registry_src)?;
    let summaries = loop {
        // Exact to avoid returning all for path/git
        match source.query_vec(&query, QueryKind::Exact) {
            std::task::Poll::Ready(res) => {
                break res?;
            }
            std::task::Poll::Pending => source.block_until_ready()?,
        }
    };
    Ok(!summaries.is_empty())
}

fn verify_unpublished(
    pkg: &Package,
    source: &mut RegistrySource<'_>,
    source_ids: &RegistrySourceIds,
    dry_run: bool,
    gctx: &GlobalContext,
) -> CargoResult<()> {
    let query = Dependency::parse(
        pkg.name(),
        Some(&pkg.version().to_exact_req().to_string()),
        source_ids.replacement,
    )?;
    let duplicate_query = loop {
        match source.query_vec(&query, QueryKind::Exact) {
            std::task::Poll::Ready(res) => {
                break res?;
            }
            std::task::Poll::Pending => source.block_until_ready()?,
        }
    };
    if !duplicate_query.is_empty() {
        // Move the registry error earlier in the publish process.
        // Since dry-run wouldn't talk to the registry to get the error, we downgrade it to a
        // warning.
        if dry_run {
            gctx.shell().warn(format!(
                "crate {}@{} already exists on {}",
                pkg.name(),
                pkg.version(),
                source.describe()
            ))?;
        } else {
            bail!(
                "crate {}@{} already exists on {}",
                pkg.name(),
                pkg.version(),
                source.describe()
            );
        }
    }

    Ok(())
}

fn verify_dependencies(
    pkg: &Package,
    registry: &Registry,
    registry_src: SourceId,
) -> CargoResult<()> {
    for dep in pkg.dependencies().iter() {
        if check_dep_has_version(dep, true)? {
            continue;
        }
        // TomlManifest::prepare_for_publish will rewrite the dependency
        // to be just the `version` field.
        if dep.source_id() != registry_src {
            if !dep.source_id().is_registry() {
                // Consider making SourceId::kind a public type that we can
                // exhaustively match on. Using match can help ensure that
                // every kind is properly handled.
                panic!("unexpected source kind for dependency {:?}", dep);
            }
            // Block requests to send to crates.io with alt-registry deps.
            // This extra hostname check is mostly to assist with testing,
            // but also prevents someone using `--index` to specify
            // something that points to crates.io.
            if registry_src.is_crates_io() || registry.host_is_crates_io() {
                bail!(
                    "crates cannot be published to crates.io with dependencies sourced from other\n\
                       registries. `{}` needs to be published to crates.io before publishing this crate.\n\
                       (crate `{}` is pulled from {})",
                    dep.package_name(),
                    dep.package_name(),
                    dep.source_id()
                );
            }
        }
    }
    Ok(())
}

pub(crate) fn prepare_transmit(
    gctx: &GlobalContext,
    ws: &Workspace<'_>,
    local_pkg: &Package,
    registry_id: SourceId,
) -> CargoResult<NewCrate> {
    let included = None; // don't filter build-targets
    let publish_pkg = prepare_for_publish(local_pkg, ws, included)?;

    let deps = publish_pkg
        .dependencies()
        .iter()
        .map(|dep| {
            // If the dependency is from a different registry, then include the
            // registry in the dependency.
            let dep_registry_id = match dep.registry_id() {
                Some(id) => id,
                None => SourceId::crates_io(gctx)?,
            };
            // In the index and Web API, None means "from the same registry"
            // whereas in Cargo.toml, it means "from crates.io".
            let dep_registry = if dep_registry_id != registry_id {
                Some(dep_registry_id.url().to_string())
            } else {
                None
            };

            Ok(NewCrateDependency {
                optional: dep.is_optional(),
                default_features: dep.uses_default_features(),
                name: dep.package_name().to_string(),
                features: dep.features().iter().map(|s| s.to_string()).collect(),
                version_req: dep.version_req().to_string(),
                target: dep.platform().map(|s| s.to_string()),
                kind: match dep.kind() {
                    DepKind::Normal => "normal",
                    DepKind::Build => "build",
                    DepKind::Development => "dev",
                }
                .to_string(),
                registry: dep_registry,
                explicit_name_in_toml: dep.explicit_name_in_toml().map(|s| s.to_string()),
                artifact: dep.artifact().map(|artifact| {
                    artifact
                        .kinds()
                        .iter()
                        .map(|x| x.as_str().into_owned())
                        .collect()
                }),
                bindep_target: dep.artifact().and_then(|artifact| {
                    artifact.target().map(|target| target.as_str().to_owned())
                }),
                lib: dep.artifact().map_or(false, |artifact| artifact.is_lib()),
            })
        })
        .collect::<CargoResult<Vec<NewCrateDependency>>>()?;
    let manifest = publish_pkg.manifest();
    let ManifestMetadata {
        ref authors,
        ref description,
        ref homepage,
        ref documentation,
        ref keywords,
        ref readme,
        ref repository,
        ref license,
        ref license_file,
        ref categories,
        ref badges,
        ref links,
        ref rust_version,
    } = *manifest.metadata();
    let rust_version = rust_version.as_ref().map(ToString::to_string);
    let readme_content = local_pkg
        .manifest()
        .metadata()
        .readme
        .as_ref()
        .map(|readme| {
            paths::read(&local_pkg.root().join(readme)).with_context(|| {
                format!("failed to read `readme` file for package `{}`", local_pkg)
            })
        })
        .transpose()?;
    if let Some(ref file) = local_pkg.manifest().metadata().license_file {
        if !local_pkg.root().join(file).exists() {
            bail!("the license file `{}` does not exist", file)
        }
    }

    let string_features = match manifest.normalized_toml().features() {
        Some(features) => features
            .iter()
            .map(|(feat, values)| {
                (
                    feat.to_string(),
                    values.iter().map(|fv| fv.to_string()).collect(),
                )
            })
            .collect::<BTreeMap<String, Vec<String>>>(),
        None => BTreeMap::new(),
    };

    Ok(NewCrate {
        name: publish_pkg.name().to_string(),
        vers: publish_pkg.version().to_string(),
        deps,
        features: string_features,
        authors: authors.clone(),
        description: description.clone(),
        homepage: homepage.clone(),
        documentation: documentation.clone(),
        keywords: keywords.clone(),
        categories: categories.clone(),
        readme: readme_content,
        readme_file: readme.clone(),
        repository: repository.clone(),
        license: license.clone(),
        license_file: license_file.clone(),
        badges: badges.clone(),
        links: links.clone(),
        rust_version,
    })
}

fn transmit(
    gctx: &GlobalContext,
    ws: &Workspace<'_>,
    pkg: &Package,
    tarball: &File,
    registry: &mut Registry,
    registry_id: SourceId,
    dry_run: bool,
    workspace_context: impl Fn() -> String,
) -> CargoResult<()> {
    let new_crate = prepare_transmit(gctx, ws, pkg, registry_id)?;

    // Do not upload if performing a dry run
    if dry_run {
        gctx.shell().warn("aborting upload due to dry run")?;
        return Ok(());
    }

    let warnings = registry.publish(&new_crate, tarball).with_context(|| {
        format!(
            "failed to publish {} v{} to registry at {}{}",
            pkg.name(),
            pkg.version(),
            registry.host(),
            workspace_context()
        )
    })?;

    if !warnings.invalid_categories.is_empty() {
        let msg = format!(
            "the following are not valid category slugs and were \
             ignored: {}. Please see https://crates.io/category_slugs \
             for the list of all category slugs. \
             ",
            warnings.invalid_categories.join(", ")
        );
        gctx.shell().warn(&msg)?;
    }

    if !warnings.invalid_badges.is_empty() {
        let msg = format!(
            "the following are not valid badges and were ignored: {}. \
             Either the badge type specified is unknown or a required \
             attribute is missing. Please see \
             https://doc.rust-lang.org/cargo/reference/manifest.html#package-metadata \
             for valid badge types and their required attributes.",
            warnings.invalid_badges.join(", ")
        );
        gctx.shell().warn(&msg)?;
    }

    if !warnings.other.is_empty() {
        for msg in warnings.other {
            gctx.shell().warn(&msg)?;
        }
    }

    Ok(())
}

/// State for tracking dependencies during upload.
struct PublishPlan {
    /// Graph of publishable packages where the edges are `(dependency -> dependent)`
    dependents: Graph<PackageId, ()>,
    /// The weight of a package is the number of unpublished dependencies it has.
    dependencies_count: HashMap<PackageId, usize>,
}

impl PublishPlan {
    /// Given a package dependency graph, creates a `PublishPlan` for tracking state.
    fn new(graph: &Graph<PackageId, ()>) -> Self {
        let dependents = graph.reversed();

        let dependencies_count: HashMap<_, _> = dependents
            .iter()
            .map(|id| (*id, graph.edges(id).count()))
            .collect();
        Self {
            dependents,
            dependencies_count,
        }
    }

    fn iter(&self) -> impl Iterator<Item = PackageId> + '_ {
        self.dependencies_count.iter().map(|(id, _)| *id)
    }

    fn is_empty(&self) -> bool {
        self.dependencies_count.is_empty()
    }

    fn len(&self) -> usize {
        self.dependencies_count.len()
    }

    /// Returns the set of packages that are ready for publishing (i.e. have no outstanding dependencies).
    ///
    /// These will not be returned in future calls.
    fn take_ready(&mut self) -> BTreeSet<PackageId> {
        let ready: BTreeSet<_> = self
            .dependencies_count
            .iter()
            .filter_map(|(id, weight)| (*weight == 0).then_some(*id))
            .collect();
        for pkg in &ready {
            self.dependencies_count.remove(pkg);
        }
        ready
    }

    /// Packages confirmed to be available in the registry, potentially allowing additional
    /// packages to be "ready".
    fn mark_confirmed(&mut self, published: impl IntoIterator<Item = PackageId>) {
        for id in published {
            for (dependent_id, _) in self.dependents.edges(&id) {
                if let Some(weight) = self.dependencies_count.get_mut(dependent_id) {
                    *weight = weight.saturating_sub(1);
                }
            }
        }
    }
}

/// Format a collection of packages as a list
///
/// e.g. "foo v0.1.0, bar v0.2.0, and baz v0.3.0".
///
/// Note: the final separator (e.g. "and" in the previous example) can be chosen.
fn package_list(pkgs: impl IntoIterator<Item = PackageId>, final_sep: &str) -> String {
    let mut names: Vec<_> = pkgs
        .into_iter()
        .map(|pkg| format!("{} v{}", pkg.name(), pkg.version()))
        .collect();
    names.sort();

    match &names[..] {
        [] => String::new(),
        [a] => a.clone(),
        [a, b] => format!("{a} {final_sep} {b}"),
        [names @ .., last] => {
            format!("{}, {final_sep} {last}", names.join(", "))
        }
    }
}

fn validate_registry(pkgs: &[&Package], reg_or_index: Option<&RegistryOrIndex>) -> CargoResult<()> {
    let reg_name = match reg_or_index {
        Some(RegistryOrIndex::Registry(r)) => Some(r.as_str()),
        None => Some(CRATES_IO_REGISTRY),
        Some(RegistryOrIndex::Index(_)) => None,
    };
    if let Some(reg_name) = reg_name {
        for pkg in pkgs {
            if let Some(allowed) = pkg.publish().as_ref() {
                if !allowed.iter().any(|a| a == reg_name) {
                    bail!(
                        "`{}` cannot be published.\n\
                         The registry `{}` is not listed in the `package.publish` value in Cargo.toml.",
                        pkg.name(),
                        reg_name
                    );
                }
            }
        }
    }

    Ok(())
}

#[cfg(test)]
mod tests {
    use crate::{
        core::{PackageId, SourceId},
        sources::CRATES_IO_INDEX,
        util::{Graph, IntoUrl},
    };

    use super::PublishPlan;

    fn pkg_id(name: &str) -> PackageId {
        let loc = CRATES_IO_INDEX.into_url().unwrap();
        PackageId::try_new(name, "1.0.0", SourceId::for_registry(&loc).unwrap()).unwrap()
    }

    #[test]
    fn parallel_schedule() {
        let mut graph: Graph<PackageId, ()> = Graph::new();
        let a = pkg_id("a");
        let b = pkg_id("b");
        let c = pkg_id("c");
        let d = pkg_id("d");
        let e = pkg_id("e");

        graph.add(a);
        graph.add(b);
        graph.add(c);
        graph.add(d);
        graph.add(e);
        graph.link(a, c);
        graph.link(b, c);
        graph.link(c, d);
        graph.link(c, e);

        let mut order = PublishPlan::new(&graph);
        let ready: Vec<_> = order.take_ready().into_iter().collect();
        assert_eq!(ready, vec![d, e]);

        order.mark_confirmed(vec![d]);
        let ready: Vec<_> = order.take_ready().into_iter().collect();
        assert!(ready.is_empty());

        order.mark_confirmed(vec![e]);
        let ready: Vec<_> = order.take_ready().into_iter().collect();
        assert_eq!(ready, vec![c]);

        order.mark_confirmed(vec![c]);
        let ready: Vec<_> = order.take_ready().into_iter().collect();
        assert_eq!(ready, vec![a, b]);

        order.mark_confirmed(vec![a, b]);
        let ready: Vec<_> = order.take_ready().into_iter().collect();
        assert!(ready.is_empty());
    }
}