session

Test session: immutable state wrapper for the Elm loop.

A TestSession holds the current model, normalized tree, and app reference. Each operation (send_event, click, etc.) returns a new session with updated state. No processes, no side effects: pure functional state threading.

Types

TestSession

opaque </>

Immutable test session. Each operation returns a new session.

The msg type is always Event because the testing infrastructure only works with simple apps (or apps whose on_event maps to Event).

pub opaque type TestSession(model)

Values

current_tree

</>

pub fn current_tree(session: TestSession(model)) -> node.Node

Return the current normalized tree.

get_app

</>

pub fn get_app(
  session: TestSession(model),
) -> app.App(model, event.Event)

Return the underlying app (for helpers that need access).

model

</>

pub fn model(session: TestSession(model)) -> model

Return the current model.

send_event

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pub fn send_event(
  session: TestSession(model),
  event: event.Event,
) -> TestSession(model)

Dispatch an event through the app’s update function. Processes resulting commands and re-renders the view.

start

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pub fn start(
  app: app.App(model, event.Event),
) -> TestSession(model)

Create a new test session from an app. Calls init, processes commands, renders and normalizes the initial view.