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diff --git a/test/lustre_test.gleam b/test/lustre_test.gleam
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+// IMPORTS ---------------------------------------------------------------------
+
+import apps/counter
+import apps/static
+import birdie
+import gleam/erlang/process
+import gleam/function
+import gleam/json
+import gleeunit
+import lustre
+import lustre/element
+import lustre/internals/patch
+import lustre/runtime.{Debug, Dispatch, Shutdown, View}
+
+// MAIN ------------------------------------------------------------------------
+
+pub fn main() {
+  gleeunit.main()
+}
+
+// TESTS -----------------------------------------------------------------------
+
+pub fn static_test() {
+  let title = "Can render static HTML"
+  let el = static.view()
+
+  birdie.snap(element.to_string(el), title)
+}
+
+pub fn counter_init_test() {
+  let title = "Can render an application's initial state."
+  let app = lustre.simple(counter.init, counter.update, counter.view)
+  let assert Ok(runtime) = lustre.start_actor(app, 0)
+  let el =
+    process.call(
+      runtime,
+      function.curry2(process.send)
+      |> function.compose(View)
+      |> function.compose(Debug),
+      100,
+    )
+
+  birdie.snap(element.to_string(el), title)
+  process.send(runtime, Shutdown)
+}
+
+pub fn counter_update_test() {
+  let title = "Can render an application's state after some updates."
+  let app = lustre.simple(counter.init, counter.update, counter.view)
+  let assert Ok(runtime) = lustre.start_actor(app, 0)
+
+  process.send(runtime, Dispatch(counter.Increment))
+  process.send(runtime, Dispatch(counter.Increment))
+  process.send(runtime, Dispatch(counter.Increment))
+
+  let el =
+    process.call(
+      runtime,
+      function.curry2(process.send)
+      |> function.compose(View)
+      |> function.compose(Debug),
+      100,
+    )
+
+  birdie.snap(element.to_string(el), title)
+  process.send(runtime, Shutdown)
+}
+
+pub fn counter_diff_test() {
+  let title = "Can compute a diff from one render to the next"
+  let app = lustre.simple(counter.init, counter.update, counter.view)
+  let assert Ok(runtime) = lustre.start_actor(app, 0)
+
+  let prev =
+    process.call(
+      runtime,
+      function.curry2(process.send)
+      |> function.compose(View)
+      |> function.compose(Debug),
+      100,
+    )
+
+  process.send(runtime, Dispatch(counter.Increment))
+  process.send(runtime, Dispatch(counter.Increment))
+  process.send(runtime, Dispatch(counter.Increment))
+
+  let next =
+    process.call(
+      runtime,
+      function.curry2(process.send)
+      |> function.compose(View)
+      |> function.compose(Debug),
+      100,
+    )
+
+  let diff = patch.elements(prev, next)
+
+  birdie.snap(json.to_string(patch.element_diff_to_json(diff)), title)
+  process.send(runtime, Shutdown)
+}