Struct MockWasmRuntime 

pub struct MockWasmRuntime { /* private fields */ }

Mock runtime that simulates async message passing

This replaces browser APIs like Worker.postMessage() and Worker.onmessage with a deterministic, testable interface.

Implementations

impl MockWasmRuntime

pub fn new() -> Self

Create a new mock runtime

pub fn on_message<F>(&mut self, handler: F)

where F: Fn(&MockMessage) + 'static,

Register a message handler (like worker.onmessage)

pub fn post_message(&self, msg: MockMessage)

Send message (like worker.postMessage)

This puts a message in the outgoing queue for the component to “send”.

Browser Fidelity (PROBAR-WASM-003)

Like receive_message, this performs a round-trip serialization to simulate structuredClone semantics.

Panics

Panics if the message cannot be serialized. This intentionally mirrors browser postMessage semantics where non-cloneable objects throw.

pub fn receive_message(&self, msg: MockMessage)

Receive a message (simulates worker sending to main thread)

This puts a message in the incoming queue to be processed by handlers.

Browser Fidelity (PROBAR-WASM-003)

To simulate real browser structuredClone semantics, the message is serialized and deserialized before being queued. This ensures that:

• Non-serializable types will panic (like they would in a browser)
• Message data is deep-copied (no shared references)

Panics

Panics if the message cannot be serialized or deserialized. This simulates browser postMessage behavior where non-cloneable objects cause errors.

pub fn tick(&mut self) -> bool

Process one message from the incoming queue

Returns true if a message was processed, false if queue was empty.

Re-entrancy Safety

Handlers may call receive_message() to queue additional messages, or even register new handlers via on_message(). This is achieved by temporarily swapping out the handlers vector during processing.

pub fn drain(&mut self)

Process all pending messages

Safety Limit

To prevent infinite loops from recursive message patterns, this method processes at most 10,000 messages. Use drain_bounded for explicit control over the limit.

pub fn drain_bounded(&mut self, max_messages: usize) -> usize

Process pending messages with explicit bound

Returns the number of messages processed.

pub fn tick_n(&mut self, n: usize) -> usize

Process up to N messages

pub fn pending_count(&self) -> usize

Get pending incoming message count

pub fn take_outgoing(&self) -> Vec<MockMessage>

Get outgoing messages (for assertions)

pub fn peek_outgoing(&self) -> Vec<MockMessage>

Peek at outgoing messages without consuming

pub fn has_outgoing(&self) -> bool

Check if there are any outgoing messages

pub fn total_processed(&self) -> usize

Get total messages processed

pub fn reset(&mut self)

Clear all queues and handlers

pub fn start(&mut self)

Start the runtime (marks it as active)

pub fn is_started(&self) -> bool

Check if runtime is started

Trait Implementations

impl Clone for MockWasmRuntime

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MockWasmRuntime

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

Formats the value using the given formatter.

impl Default for MockWasmRuntime

fn default() -> Self

Returns the “default value” for a type.