feat: add alternating autotiling

src/it/tests/t0055_autotiling.rs

@@ -0,0 +1,58 @@
+use {
+    crate::{
+        it::{test_error::TestResult, testrun::TestRun},
+        tree::{ContainerSplit, Node, ToplevelNodeBase},
+    },
+    std::rc::Rc,
+};
+
+testcase!();
+
+async fn test(run: Rc<TestRun>) -> TestResult {
+    run.backend.install_default()?;
+    run.cfg.set_autotile(true)?;
+
+    let client = run.create_client().await?;
+
+    let win1 = client.create_window().await?;
+    win1.map().await?;
+    let root = win1.tl.container_parent()?;
+    tassert_eq!(root.split.get(), ContainerSplit::Horizontal);
+
+    let win2 = client.create_window().await?;
+    win2.map().await?;
+    client.sync().await;
+
+    tassert_eq!(root.split.get(), ContainerSplit::Horizontal);
+    tassert_eq!(win1.tl.container_parent()?.node_id(), root.node_id());
+    tassert_eq!(win2.tl.container_parent()?.node_id(), root.node_id());
+
+    let win3 = client.create_window().await?;
+    win3.map().await?;
+    client.sync().await;
+
+    let v_group = win3.tl.container_parent()?;
+    tassert_eq!(root.split.get(), ContainerSplit::Horizontal);
+    tassert_eq!(v_group.split.get(), ContainerSplit::Vertical);
+    tassert_eq!(win2.tl.container_parent()?.node_id(), v_group.node_id());
+
+    let win4 = client.create_window().await?;
+    win4.map().await?;
+    client.sync().await;
+
+    let h_group = win4.tl.container_parent()?;
+    tassert_eq!(h_group.split.get(), ContainerSplit::Horizontal);
+    tassert_eq!(win3.tl.container_parent()?.node_id(), h_group.node_id());
+    let h_parent = match h_group
+        .tl_data()
+        .parent
+        .get()
+        .and_then(|p| p.node_into_container())
+    {
+        Some(parent) => parent,
+        None => bail!("autotile group does not have a container parent"),
+    };
+    tassert_eq!(h_parent.node_id(), v_group.node_id());
+
+    Ok(())
+}