Plushie.Test (Plushie v0.6.0)

Test helpers for Plushie applications.

Setup

Call Plushie.Test.setup!() in your test/test_helper.exs before ExUnit.start():

# test/test_helper.exs
Plushie.Test.setup!()
ExUnit.start()

This starts the shared renderer session pool and configures ExUnit to exclude tests tagged for backends not currently active.

Backend selection

Set PLUSHIE_TEST_BACKEND to choose the backend:

mix test                                    # mock (default)
PLUSHIE_TEST_BACKEND=headless mix test       # headless rendering
PLUSHIE_TEST_BACKEND=windowed mix test       # real windows

Backend-specific tests

Tag tests with the minimum backend they require:

@tag backend: :headless   # runs in headless + windowed, skipped in mock
test "renders correctly" do ... end

@tag backend: :windowed   # runs only in windowed
test "screenshot matches" do ... end

Backend capability is hierarchical: mock < headless < windowed. Tag with the lowest backend that provides what the test needs. Untagged tests run in all modes.

Tree snapshot testing

test "initial view snapshot" do
  model = MyApp.init([])
  tree = MyApp.view(model)
  Plushie.Test.assert_tree_snapshot(tree, "test/snapshots/initial_view.json")
end

On first run, assert_tree_snapshot/2 writes the snapshot file. On subsequent runs, it compares against the stored snapshot. Update snapshots with:

PLUSHIE_UPDATE_SNAPSHOTS=1 mix test

Summary

Functions

assert_tree_snapshot(tree, path)

Asserts that tree matches the stored structural snapshot at path.

setup!(opts \\ [])

Sets up the Plushie test infrastructure.

Functions

assert_tree_snapshot(tree, path)

@spec assert_tree_snapshot(tree :: map(), path :: String.t()) :: :ok

Asserts that tree matches the stored structural snapshot at path.

On first run (file does not exist), writes the snapshot. On subsequent runs, compares and fails with a diff if different. Set PLUSHIE_UPDATE_SNAPSHOTS=1 to overwrite existing snapshots.

setup!(opts \\ [])

@spec setup!(opts :: keyword()) :: keyword()

Sets up the Plushie test infrastructure.

Call this from your test/test_helper.exs before ExUnit.start(). Starts the shared renderer session pool and configures backend-based test exclusions.

Returns the ExUnit exclusion options -- pass them to ExUnit.start/1:

# test/test_helper.exs
plushie_opts = Plushie.Test.setup!()
ExUnit.start(plushie_opts)