Enum DepScope 

pub enum DepScope {
    Shared,
    PerWorker,
    Cloneable,
    Hosted,
    HostedRpc,
}

Sharing strategy declared on a #[test_dep]. Controls how the dependency interacts with output capturing and parallel test execution.

See book/src/design/sharing-strategy.md for the full description.

Variants

Shared

Today’s behaviour: a single materialized instance shared by every test. Forces single-threaded execution when output capturing is on, because the Arc<dyn Any> cannot cross the parent/worker process boundary.

PerWorker

Each worker child materializes its own instance independently. Tests inside one worker share the instance.

Cloneable

Parent runs the constructor once and produces wire bytes; each worker reconstructs a local instance from those bytes via the registered worker reconstructor (worker_fn).

Hosted

Owner runs once in the parent test runner process and stays alive for the entire suite. The parent produces a descriptor (via HostedDep::descriptor) and ships those descriptor bytes to every worker. Each worker reconstructs a handle via HostedDep::from_descriptor. The owner is held in the parent process so singleton services (TCP listeners, Docker containers, gRPC server clients, env-based runtimes) are not duplicated per worker.

HostedRpc

Like Self::Hosted, but the owner stays in the parent AND workers talk back to it via the runtime’s built-in RPC layer instead of reaching out via their own transport. The dep implementor provides a HostedRpcDep impl (sync owners) — or, under the tokio feature, an AsyncHostedRpcDep impl (async owners) — on the owner type with a stub type, a method dispatch function, and a stub builder.

Implementations

impl DepScope

pub fn requires_single_thread_when_capturing(&self) -> bool

Returns true for scopes that materialize in the parent process and therefore force single-threaded fallback when capturing is on.

pub fn parent_must_materialize_under_spawn_workers(&self) -> bool

Returns true for scopes the parent should still materialize even when it is otherwise delegating dependency construction to workers (i.e. skip_creating_dependencies is set). Cloneable deps need the parent to compute the wire form; Hosted / HostedRpc deps need the parent to hold the owner alive for the whole suite.

Trait Implementations

impl Clone for DepScope

fn clone(&self) -> DepScope

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for DepScope

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Default for DepScope

fn default() -> DepScope

Returns the “default value” for a type.

impl Hash for DepScope

fn hash<__H>(&self, state: &mut __H)

where __H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for DepScope

fn eq(&self, other: &DepScope) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for DepScope

impl Eq for DepScope

impl StructuralPartialEq for DepScope