refactor(cmd/compose/run): remove redundant `len` check

From the Go specification [1]:

  "1. For a nil slice, the number of iterations is 0."

`len` returns 0 if the slice is nil [2]. Therefore, checking
`len(v) > 0` before a loop is unnecessary.

[1]: https://go.dev/ref/spec#For_range
[2]: https://pkg.go.dev/builtin#len

Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>

cmd/compose/run.go

@@ -80,11 +80,10 @@ func (options runOptions) apply(project *types.Project) error {
 
 	target.Tty = !options.noTty
 	target.StdinOpen = options.interactive
+
+	// --service-ports and --publish are incompatible
 	if !options.servicePorts {
 		target.Ports = []types.ServicePortConfig{}
-	}
-	if len(options.publish) > 0 {
-		target.Ports = []types.ServicePortConfig{}
 		for _, p := range options.publish {
 			config, err := types.ParsePortConfig(p)
 			if err != nil {
@@ -93,14 +92,13 @@ func (options runOptions) apply(project *types.Project) error {
 			target.Ports = append(target.Ports, config...)
 		}
 	}
-	if len(options.volumes) > 0 {
-		for _, v := range options.volumes {
-			volume, err := loader.ParseVolume(v)
-			if err != nil {
-				return err
-			}
-			target.Volumes = append(target.Volumes, volume)
+
+	for _, v := range options.volumes {
+		volume, err := loader.ParseVolume(v)
+		if err != nil {
+			return err
 		}
+		target.Volumes = append(target.Volumes, volume)
 	}
 
 	for i, s := range project.Services {

pkg/e2e/compose_run_test.go

@@ -96,10 +96,18 @@ func TestLocalComposeRun(t *testing.T) {
 	})
 
 	t.Run("compose run --publish", func(t *testing.T) {
-		c.RunDockerComposeCmd(t, "-f", "./fixtures/run-test/compose.yaml", "run", "--publish", "8081:80", "-d", "back",
+		c.RunDockerComposeCmd(t, "-f", "./fixtures/run-test/ports.yaml", "run", "--publish", "8081:80", "-d", "back",
 			"/bin/sh", "-c", "sleep 1")
 		res := c.RunDockerCmd(t, "ps")
 		assert.Assert(t, strings.Contains(res.Stdout(), "8081->80/tcp"), res.Stdout())
+		assert.Assert(t, !strings.Contains(res.Stdout(), "8082->80/tcp"), res.Stdout())
+	})
+
+	t.Run("compose run --service-ports", func(t *testing.T) {
+		c.RunDockerComposeCmd(t, "-f", "./fixtures/run-test/ports.yaml", "run", "--service-ports", "-d", "back",
+			"/bin/sh", "-c", "sleep 1")
+		res := c.RunDockerCmd(t, "ps")
+		assert.Assert(t, strings.Contains(res.Stdout(), "8082->80/tcp"), res.Stdout())
 	})
 
 	t.Run("compose run orphan", func(t *testing.T) {

pkg/e2e/fixtures/run-test/ports.yaml

@@ -0,0 +1,6 @@
+version: '3.8'
+services:
+  back:
+    image: alpine
+    ports:
+      - 8082:80