fix: send commands in a goroutine without executing them immediately

The commands channel handler handles commands and their execution. We
should not execute them ourself in the event loop and instead send them
to the commands channel where the handles will take care of executing
them.

Fixes: f5da8d0 (fix: handle nested SequenceMsg in event loop and use sync.WaitGroup f… (#1463))

Author: aymanbagabas

tea.go

@@ -377,6 +377,17 @@ func (p *Program) disableMouse() {
 	p.renderer.disableMouseSGRMode()
 }
 
+// sendCmd a helper function to send a command to the program's command
+// channel. It will not block if the program is already shutting down, in which
+// case it will simply return without sending the command.
+func (p *Program) sendCmd(cmds chan Cmd, cmd Cmd) {
+	select {
+	case <-p.ctx.Done():
+		return
+	case cmds <- cmd:
+	}
+}
+
 // eventLoop is the central message loop. It receives and handles the default
 // Bubble Tea messages, update the model and triggers redraws.
 func (p *Program) eventLoop(model Model, cmds chan Cmd) (Model, error) {
@@ -475,7 +486,7 @@ func (p *Program) eventLoop(model Model, cmds chan Cmd) (Model, error) {
 					if cmd == nil {
 						continue
 					}
-					go p.Send(cmd())
+					go p.sendCmd(cmds, cmd)
 				}
 				continue
 
@@ -492,23 +503,16 @@ func (p *Program) eventLoop(model Model, cmds chan Cmd) (Model, error) {
 						case BatchMsg:
 							var wg sync.WaitGroup
 							for _, cmd := range msg {
-								if cmd == nil {
-									continue
-								}
 								wg.Add(1)
-								cmd := cmd
 								go func() {
 									defer wg.Done()
-									p.Send(cmd())
+									p.sendCmd(cmds, cmd)
 								}()
 							}
 							wg.Wait()
 						case sequenceMsg:
 							for _, cmd := range msg {
-								if cmd == nil {
-									continue
-								}
-								p.Send(cmd())
+								p.sendCmd(cmds, cmd)
 							}
 						default:
 							p.Send(msg)