Terminate running background transform on exit

Close #4422

src/terminal.go

@@ -9,6 +9,7 @@ import (
 	"math"
 	"net"
 	"os"
+	"os/exec"
 	"os/signal"
 	"regexp"
 	"sort"
@@ -377,6 +378,7 @@ type Terminal struct {
 	version            int64
 	revision           revision
 	bgVersion          int64
+	runningCmds        *util.ConcurrentSet[*exec.Cmd]
 	reqBox             *util.EventBox
 	initialPreviewOpts previewOpts
 	previewOpts        previewOpts
@@ -1030,6 +1032,7 @@ func NewTerminal(opts *Options, eventBox *util.EventBox, executor *util.Executor
 		proxyScript:        opts.ProxyScript,
 		merger:             EmptyMerger(revision{}),
 		selected:           make(map[int32]selectedItem),
+		runningCmds:        util.NewConcurrentSet[*exec.Cmd](),
 		reqBox:             util.NewEventBox(),
 		initialPreviewOpts: opts.Preview,
 		previewOpts:        opts.Preview,
@@ -4377,6 +4380,7 @@ func (t *Terminal) captureAsync(a action, firstLineOnly bool, callback func(stri
 			reader := bufio.NewReader(out)
 			var output string
 			if err := cmd.Start(); err == nil {
+				t.runningCmds.Add(cmd)
 				if firstLineOnly {
 					output, _ = reader.ReadString('\n')
 					output = strings.TrimRight(output, "\r\n")
@@ -4385,6 +4389,7 @@ func (t *Terminal) captureAsync(a action, firstLineOnly bool, callback func(stri
 					output = string(bytes)
 				}
 				cmd.Wait()
+				t.runningCmds.Remove(cmd)
 			}
 			t.callbackChan <- versionedCallback{version, func() { callback(output) }}
 		}
@@ -5053,6 +5058,9 @@ func (t *Terminal) Loop() error {
 			if code <= ExitNoMatch && t.history != nil {
 				t.history.append(string(t.input))
 			}
+			t.runningCmds.ForEach(func(cmd *exec.Cmd) {
+				util.KillCommand(cmd)
+			})
 			running = false
 			t.mutex.Unlock()
 		}

src/util/concurrent_set.go

@@ -0,0 +1,39 @@
+package util
+
+import "sync"
+
+// ConcurrentSet is a thread-safe set implementation.
+type ConcurrentSet[T comparable] struct {
+	lock  sync.RWMutex
+	items map[T]struct{}
+}
+
+// NewConcurrentSet creates a new ConcurrentSet.
+func NewConcurrentSet[T comparable]() *ConcurrentSet[T] {
+	return &ConcurrentSet[T]{
+		items: make(map[T]struct{}),
+	}
+}
+
+// Add adds an item to the set.
+func (s *ConcurrentSet[T]) Add(item T) {
+	s.lock.Lock()
+	defer s.lock.Unlock()
+	s.items[item] = struct{}{}
+}
+
+// Remove removes an item from the set.
+func (s *ConcurrentSet[T]) Remove(item T) {
+	s.lock.Lock()
+	defer s.lock.Unlock()
+	delete(s.items, item)
+}
+
+// ForEach iterates over each item in the set and applies the provided function.
+func (s *ConcurrentSet[T]) ForEach(fn func(item T)) {
+	s.lock.RLock()
+	defer s.lock.RUnlock()
+	for item := range s.items {
+		fn(item)
+	}
+}