Breeze.Test (Breeze v0.4.0)

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Public helpers for deterministic Breeze view tests.

Breeze.Test can render a view against a fixed terminal size, dispatch input and events without starting the interactive server.

Example

defmodule MyApp.CounterTest do
  use ExUnit.Case, async: true

  test "counter snapshot" do
    session = Breeze.Test.start!(MyApp.CounterView, size: {30, 5})
    on_exit(fn -> Breeze.Test.stop(session) end)

    assert Breeze.Test.render!(session) =~ "Counter: 0"

    assert {:noreply, _focused, true} = Breeze.Test.input(session, "ArrowUp")
    assert Breeze.Test.render!(session) =~ "Counter: 1"
  end
end

Summary

Types

t()

A deterministic view-test session.

Functions

event(session, change, event)

Dispatches a named event and payload directly to the view.

info(session, message)

Dispatches a message to the view's handle_info/2 callback.

input(session, key)

Dispatches a decoded key or input event to the view.

metadata(session)

Returns the current metadata for the view session.

render(session, opts \\ [])

Renders the current view state and returns its terminal content.

render!(session, opts \\ [])

Renders the current view state, raising on failure.

start(view, opts \\ [])

Starts a deterministic test session for view.

start!(view, opts \\ [])

Starts a deterministic test session and returns it, raising on failure.

stop(test)

Stops a test session.

Types

t()

@type t() :: %Breeze.Test{
  pid: pid(),
  terminal: %Termite.Terminal{adapter: term(), reader: term(), size: term()}
}

A deterministic view-test session.

Functions

event(session, change, event)

@spec event(t(), term(), map()) :: term()

Dispatches a named event and payload directly to the view.

info(session, message)

@spec info(t(), term()) :: term()

Dispatches a message to the view's handle_info/2 callback.

input(session, key)

@spec input(t(), term()) :: term()

Dispatches a decoded key or input event to the view.

metadata(session)

@spec metadata(t()) :: term()

Returns the current metadata for the view session.

render(session, opts \\ [])

@spec render(t(), keyword()) :: {:ok, String.t()} | {:error, term()}

Renders the current view state and returns its terminal content.

render!(session, opts \\ [])

@spec render!(t(), keyword()) :: String.t()

Renders the current view state, raising on failure.

start(view, opts \\ [])

@spec start(module(), keyword()) :: {:ok, t()} | {:error, term()}

Starts a deterministic test session for view.

Options include:

  • :size - terminal size as {width, height} or a dimensions map. Defaults to 80x24.
  • :terminal - an existing %Termite.Terminal{}. Takes precedence over :size.
  • :theme - the theme used to render the view.
  • :start_opts - options passed to the view's mount/2 callback.
  • :global_keybindings - keybindings active for the test session.

start!(view, opts \\ [])

@spec start!(module(), keyword()) :: t()

Starts a deterministic test session and returns it, raising on failure.

stop(test)

@spec stop(t()) :: :ok

Stops a test session.