Testing Brew components

Brew.test mounts a component and performs real snapshot round-trips through the update pipeline (JSON encode, checksum, hydrate, actions, render). No browser required.

Setup

Register providers the same way as production (at least Brew + Crema when you assert HTML from views). In tests, call Brew.reset() / Kona.reset() between cases if you boot a full application.

Kotlin

@Test
fun increments() {
    Brew.test(Counter::class.java, mapOf("start" to 2))
        .assertSet("count", 2)
        .call("increment")
        .assertSet("count", 3)
        .assertSee(3)
}

Java

@Test
void increments() {
    Brew.test(Counter.class, Map.of("start", 2))
        .assertSet("count", 2)
        .call("increment")
        .assertSet("count", 3)
        .assertSee(3);
}

You can also address by name: Brew.test("counter", mapOf("start" to 2)).

Interactions

Method	Role
set(name, value) / set(map)	Property updates
toggle(name)	Flip boolean
call(method, *params)	Invoke action
refresh()	$refresh
commit()	$commit

Assertions

Assertion	Checks
assertSet / assertNotSet	Property equals (loose by default; strict = true for ==)
assertCount	Collection / map / array / CharSequence size
assertSee / assertDontSee	Visible text (HTML-escaped by default)
assertSeeHtml / assertDontSeeHtml	Raw HTML substring
assertSeeInOrder	Multiple needles in order
assertViewHas / assertViewIs	View data / view name
assertRenderSkipped / assertRenderNotSkipped	skipRender / @Renderless
assertStatus	Last HTTP status from the round-trip
assertForbidden / assertUnauthorized	403 / 401

Accessors

val t = Brew.test("counter")
t.instance()   // live Component
t.id()
t.html()       // last HTML (optional strip of wire:snapshot/effects)
t.get("todos.0.title")
t.snapshot()
t.effects()
t.viewData("title")

Scaffold

./grind make:brew counter --test

HTTP smoke tests

Samples also exercise the real endpoint: GET / for embedded HTML, then POST /brew/update with X-Brew, CSRF cookie, and a snapshot taken from wire:snapshot. Prefer Brew.test for component logic; use HTTP tests for middleware, CSRF, and asset injection.

Next

• Components — what you are testing
• Actions — call targets
• Lifecycle — hooks that run inside each round-trip