Validate project names for Docker Compose compatibility

cmd/project/project_create.go

@@ -11,6 +11,7 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
+	"regexp"
 	"slices"
 	"sort"
 	"strings"
@@ -44,6 +45,50 @@ var gitlabCITemplate string
 
 const versionLatest = "latest"
 
+const (
+	// projectNameHelp is the help text shown under the project name input.
+	projectNameHelp = "The name of the project directory to create"
+	// projectNameRule describes which characters are allowed in a project name.
+	// It is shared between the up-front validation error and the live form hint
+	// so both stay in sync.
+	projectNameRule = "only lowercase letters, digits, dashes (-) and underscores (_) are allowed, and it must start with a lowercase letter or digit"
+)
+
+// composeProjectNameRegexp matches names that are valid as a Docker Compose
+// project name. Docker Compose only allows lowercase letters, digits, dashes
+// and underscores, and the name must start with a lowercase letter or digit.
+// Anything else (uppercase letters, umlauts, spaces, dots, …) is rejected by
+// Docker Compose once the generated Docker setup runs from the project
+// directory, so we reject such project names up front.
+var composeProjectNameRegexp = regexp.MustCompile(`^[a-z0-9][a-z0-9_-]*$`)
+
+// validateProjectName ensures the project folder name can be used as a Docker
+// Compose project name. Only the final path element is relevant, as that is
+// what Docker Compose uses to derive the project name.
+func validateProjectName(name string) error {
+	base := filepath.Base(name)
+
+	if !composeProjectNameRegexp.MatchString(base) {
+		return fmt.Errorf("invalid project name %q: %s, so it can be used as a Docker Compose project name", base, projectNameRule)
+	}
+
+	return nil
+}
+
+// projectNameFieldDescription returns the description shown under the project
+// name input in the interactive form. While the typed name is invalid it
+// returns the rule highlighted in red, validating the input live; otherwise it
+// returns the regular help text.
+func projectNameFieldDescription(name string) string {
+	if name != "" {
+		if err := validateProjectName(name); err != nil {
+			return tui.RedText.Render(projectNameRule)
+		}
+	}
+
+	return projectNameHelp
+}
+
 var projectCreateCmd = &cobra.Command{
 	Use:   "create [name] [version]",
 	Short: "Create a new Shopware 6 project",
@@ -220,13 +265,18 @@ var projectCreateCmd = &cobra.Command{
 					formGroups = append(formGroups, huh.NewGroup(
 						huh.NewInput().
 							Title("Project Name").
-							Description("The name of the project directory to create").
+							DescriptionFunc(func() string {
+								return projectNameFieldDescription(projectFolder)
+							}, &projectFolder).
 							Placeholder("my-shopware-project").
 							Value(&projectFolder).
 							Validate(func(s string) error {
 								if s == "" {
 									return fmt.Errorf("project name is required")
 								}
+								if err := validateProjectName(s); err != nil {
+									return err
+								}
 								if info, err := os.Stat(s); err == nil && info.IsDir() {
 									empty, err := system.IsDirEmpty(s)
 									if err != nil {
@@ -402,6 +452,10 @@ var projectCreateCmd = &cobra.Command{
 			}
 		}
 
+		if err := validateProjectName(projectFolder); err != nil {
+			return err
+		}
+
 		missingDeps := system.CheckProjectDependencies(cmd.Context(), useDocker)
 
 		validDeployments := map[string]bool{

cmd/project/project_create_test.go

@@ -67,6 +67,84 @@ func TestResolveVersion(t *testing.T) {
 	})
 }
 
+func TestValidateProjectName(t *testing.T) {
+	t.Parallel()
+
+	validNames := []string{
+		"my-shopware-project",
+		"myshop",
+		"my_shop",
+		"shop123",
+		"123shop",
+		"a",
+		"path/to/my-shop",
+	}
+
+	for _, name := range validNames {
+		t.Run("valid: "+name, func(t *testing.T) {
+			t.Parallel()
+			assert.NoError(t, validateProjectName(name))
+		})
+	}
+
+	invalidNames := []string{
+		"MyShop",
+		"myShop",
+		"SHOP",
+		"müller",
+		"über-shop",
+		"Müller-Shop",
+		"café",
+		"straße",
+		"my shop",
+		"my.shop",
+		"shop!",
+		"-shop",
+		"_shop",
+		"ä",
+		"",
+		"path/to/müller",
+		"path/to/MyShop",
+	}
+
+	for _, name := range invalidNames {
+		t.Run("invalid: "+name, func(t *testing.T) {
+			t.Parallel()
+			err := validateProjectName(name)
+			assert.Error(t, err)
+			assert.Contains(t, err.Error(), "invalid project name")
+		})
+	}
+}
+
+func TestProjectNameFieldDescription(t *testing.T) {
+	t.Parallel()
+
+	t.Run("empty shows help text", func(t *testing.T) {
+		t.Parallel()
+		assert.Equal(t, projectNameHelp, projectNameFieldDescription(""))
+	})
+
+	t.Run("valid name shows help text", func(t *testing.T) {
+		t.Parallel()
+		assert.Equal(t, projectNameHelp, projectNameFieldDescription("my-shop"))
+	})
+
+	t.Run("uppercase name shows the rule", func(t *testing.T) {
+		t.Parallel()
+		desc := projectNameFieldDescription("MyShop")
+		assert.NotEqual(t, projectNameHelp, desc)
+		assert.Contains(t, desc, projectNameRule)
+	})
+
+	t.Run("umlaut name shows the rule", func(t *testing.T) {
+		t.Parallel()
+		desc := projectNameFieldDescription("müller")
+		assert.NotEqual(t, projectNameHelp, desc)
+		assert.Contains(t, desc, projectNameRule)
+	})
+}
+
 func TestSetupDeployment(t *testing.T) {
 	t.Parallel()
 	t.Run("none creates no files", func(t *testing.T) {