Struct ComposeTestRule 

pub struct ComposeTestRule { /* private fields */ }

Headless harness for exercising compositions in tests.

ComposeTestRule mirrors the ergonomics of the Jetpack Compose testing APIs while remaining lightweight and allocation-friendly for unit tests. It owns an in-memory applier and exposes helpers for driving recomposition and draining frame callbacks without requiring a windowing backend.

Implementations

impl ComposeTestRule

pub fn new() -> Self

Create a new test rule backed by the default in-memory applier.

pub fn set_content( &mut self, content: impl FnMut() + 'static, ) -> Result<(), NodeError>

Install the provided content into the composition and perform an initial render.

pub fn recomposition(&mut self) -> Result<(), NodeError>

Force a recomposition using the currently installed content.

pub fn advance_frame(&mut self, frame_time_nanos: u64) -> Result<(), NodeError>

Drain scheduled frame callbacks at the supplied timestamp and process any resulting work until the composition becomes idle.

pub fn pump_until_idle(&mut self) -> Result<(), NodeError>

Drive the composition until there are no pending renders, invalidated scopes, or enqueued node mutations remaining.

pub fn runtime_handle(&self) -> RuntimeHandle

Access the runtime driving this rule. Useful for constructing shared state objects within the composition.

pub fn applier_mut(&mut self) -> ApplierGuard<'_, MemoryApplier>

Gain mutable access to the underlying in-memory applier for assertions about the produced node tree.

pub fn dump_tree(&mut self) -> String

Dump the current node tree as text for debugging

pub fn has_content(&self) -> bool

Returns whether user content has been installed in this rule.

pub fn root_id(&self) -> Option<NodeId>

Returns the id of the root node produced by the current composition.

pub fn composition(&mut self) -> &mut Composition<MemoryApplier>

Gain mutable access to the raw composition for advanced scenarios.

Trait Implementations

impl Default for ComposeTestRule

fn default() -> Self

Returns the “default value” for a type.