feat: support killing panes and groups

pkg/cy/api/tree.go

@@ -141,6 +141,10 @@ func (t *TreeModule) Parent(id tree.NodeID) *tree.NodeID {
 	return &parentId
 }
 
+func (t *TreeModule) Kill(id tree.NodeID) error {
+	return t.Tree.RemoveNode(id)
+}
+
 func (t *TreeModule) Root() tree.NodeID {
 	return t.Tree.Root().Id()
 }

pkg/cy/client.go

@@ -46,6 +46,9 @@ type Client struct {
 	outerLayers *screen.Layers
 	renderer    *stream.Renderer
 
+	// history is an array of all of the panes this client has attached to
+	history []tree.NodeID
+
 	raw  emu.Terminal
 	info screen.RenderContext
 }
@@ -300,8 +303,35 @@ func (c *Client) Attach(node tree.Node) error {
 
 	c.muxClient.Attach(c.Ctx(), pane.Screen())
 
+	go func() {
+		select {
+		case <-c.Ctx().Done():
+			return
+		case <-c.muxClient.Attachment().Ctx().Done():
+			return
+		case <-pane.Ctx().Done():
+			// if the pane dies, just re-attach to the last node the user visited
+			c.RLock()
+			history := c.history
+			c.RUnlock()
+
+			if len(history) < 2 {
+				// TODO(cfoust): 09/20/23
+				return
+			}
+
+			node, ok := c.cy.tree.NodeById(history[len(history)-2])
+			if !ok {
+				return
+			}
+			c.Attach(node)
+			return
+		}
+	}()
+
 	c.Lock()
 	c.node = node
+	c.history = append(c.history, node.Id())
 	c.Unlock()
 
 	// Update bindings

pkg/cy/cy-boot.janet

@@ -37,6 +37,12 @@
       (0) # Gets the first index, the editor
       (pane/attach))))
 
+(key/bind
+  [prefix "x"]
+  "kill the current pane"
+  (fn [&]
+    (tree/kill (pane/current))))
+
 (key/bind
   [prefix "l"]
   "jump to a shell"

pkg/cy/cy_test.go

@@ -186,3 +186,21 @@ func TestScopes(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, 3, len(client.binds.Scopes()))
 }
+
+func TestPaneKill(t *testing.T) {
+	server := setupServer(t)
+	defer server.Release()
+
+	_, client, err := server.Standard()
+	require.NoError(t, err)
+
+	require.NoError(t, client.execute(`
+(def shell (cmd/new (tree/root) "/tmp"))
+(pp shell)
+(pane/attach shell)
+(tree/kill shell)
+`))
+	time.Sleep(100 * time.Millisecond) // lol
+	leaves := server.cy.tree.Leaves()
+	require.Equal(t, leaves[0].Id(), client.Node().Id())
+}

pkg/cy/janet.go

@@ -24,6 +24,14 @@ type CmdParams struct {
 	Args    []string
 }
 
+// execute runs some Janet code on behalf of the Client. This is only used in testing.
+func (c *Client) execute(code string) error {
+	return c.cy.janet.ExecuteCall(c.Ctx(), c, janet.Call{
+		Code:    []byte(code),
+		Options: janet.DEFAULT_CALL_OPTIONS,
+	})
+}
+
 func (c *Cy) initJanet(ctx context.Context) (*janet.VM, error) {
 	vm, err := janet.New(ctx)
 	if err != nil {

pkg/mux/screen/server/client.go

@@ -36,6 +36,10 @@ func (c *Client) State() *tty.State {
 	return screen.State()
 }
 
+func (c *Client) Attachment() *util.Lifetime {
+	return c.attachment
+}
+
 func (c *Client) Updates() *mux.Updater {
 	return c.publisher.Subscribe()
 }