Add merge to ShellCommand properties in config

Signed-off-by: Stoica-Marcu Floris-Andrei <floris.sm@gmail.com>

cli/compose/loader/merge.go

@@ -59,6 +59,7 @@ func mergeServices(base, override []types.ServiceConfig) ([]types.ServiceConfig,
 			reflect.TypeOf([]types.ServiceConfigObjConfig{}): mergeSlice(toServiceConfigObjConfigsMap, toSServiceConfigObjConfigsSlice),
 			reflect.TypeOf(&types.UlimitsConfig{}):           mergeUlimitsConfig,
 			reflect.TypeOf([]types.ServiceVolumeConfig{}):    mergeSlice(toServiceVolumeConfigsMap, toServiceVolumeConfigsSlice),
+			reflect.TypeOf(types.ShellCommand{}):             mergeShellCommand,
 			reflect.TypeOf(&types.ServiceNetworkConfig{}):    mergeServiceNetworkConfig,
 		},
 	}
@@ -235,9 +236,9 @@ func mergeUlimitsConfig(dst, src reflect.Value) error {
 }
 
 //nolint: unparam
-func mergeServiceVolumeConfig(dst, src reflect.Value) error {
-	if dst.Elem().FieldByName("target").String() == src.Elem().FieldByName("target").String() {
-		dst.Set(src.Elem())
+func mergeShellCommand(dst, src reflect.Value) error {
+	if src.Len() != 0 {
+		dst.Set(src)
 	}
 	return nil
 }

cli/compose/loader/merge_test.go

@@ -1017,6 +1017,59 @@ func TestLoadMultipleNetworks(t *testing.T) {
 	}, config)
 }
 
+func TestLoadMultipleServiceCommands(t *testing.T) {
+	base := map[string]interface{}{
+		"version": "3.7",
+		"services": map[string]interface{}{
+			"foo": map[string]interface{}{
+				"image":   "baz",
+				"command": "foo bar",
+			},
+		},
+		"volumes":  map[string]interface{}{},
+		"networks": map[string]interface{}{},
+		"secrets":  map[string]interface{}{},
+		"configs":  map[string]interface{}{},
+	}
+	override := map[string]interface{}{
+		"version": "3.7",
+		"services": map[string]interface{}{
+			"foo": map[string]interface{}{
+				"image":   "baz",
+				"command": "foo baz",
+			},
+		},
+		"volumes":  map[string]interface{}{},
+		"networks": map[string]interface{}{},
+		"secrets":  map[string]interface{}{},
+		"configs":  map[string]interface{}{},
+	}
+	configDetails := types.ConfigDetails{
+		ConfigFiles: []types.ConfigFile{
+			{Filename: "base.yml", Config: base},
+			{Filename: "override.yml", Config: override},
+		},
+	}
+	config, err := Load(configDetails)
+	assert.NilError(t, err)
+	assert.DeepEqual(t, &types.Config{
+		Filename: "base.yml",
+		Version:  "3.7",
+		Services: []types.ServiceConfig{
+			{
+				Name:        "foo",
+				Image:       "baz",
+				Command:     types.ShellCommand{"foo", "baz"},
+				Environment: types.MappingWithEquals{},
+			},
+		},
+		Volumes:  map[string]types.VolumeConfig{},
+		Secrets:  map[string]types.SecretConfig{},
+		Configs:  map[string]types.ConfigObjConfig{},
+		Networks: map[string]types.NetworkConfig{},
+	}, config)
+}
+
 func TestLoadMultipleServiceVolumes(t *testing.T) {
 	base := map[string]interface{}{
 		"version": "3.7",