add validation for user created names

closes #39

cli/cmd/new.go

@@ -46,6 +46,9 @@ func newNew(a newArgs) (*newCmd, error) {
 }
 
 func (c *newCmd) run() error {
+	if err := workspace.ValidateName(c.name); err != nil {
+		return log.WithUserMessage(err, fmt.Sprintf("Validation error: %v", err))
+	}
 	projectPath, _ := filepath.Abs(c.name)
 	repo, err := c.repoURL()
 	if err != nil {

cli/cmd/stage.go

@@ -40,6 +40,10 @@ func newStage(a stageArgs) (*stageCmd, error) {
 }
 
 func (c *stageCmd) new() error {
+	if err := workspace.ValidateName(c.stage); err != nil {
+		return log.WithUserMessage(err, fmt.Sprintf("Validation error: %v", err))
+	}
+
 	if c.account == "" {
 		accounts := c.store.Workspace().AccountNames()
 		if len(accounts) > 1 {

workspace/validate.go

@@ -1,6 +1,9 @@
 package workspace
 
-import "fmt"
+import (
+	"fmt"
+	"regexp"
+)
 
 var reservedFunctionNames = []string{
 	"public",
@@ -22,3 +25,44 @@ type ErrReservedName struct {
 func (e *ErrReservedName) Error() string {
 	return fmt.Sprintf("name \"%s\" is reserved", e.Name)
 }
+
+type ErrNameTooLong struct {
+	Name      string
+	MaxLength int
+}
+
+func (e *ErrNameTooLong) Error() string {
+	return fmt.Sprintf("the name %s is too long, maximum allowed length is %d", e.Name, e.MaxLength)
+}
+
+type ErrForbiddenCharacters struct {
+	Name              string
+	AllowedCharacters string
+}
+
+func (e *ErrForbiddenCharacters) Error() string {
+	return fmt.Sprintf("the name %s contains forbidden characters, it must only contain the following: %s", e.Name, e.AllowedCharacters)
+}
+
+const (
+	maxNameLength                = 16
+	allowedCharactersDescription = "numbers, letters and the special character -"
+)
+
+var allowedCharactersRegex = regexp.MustCompile(`^[a-zA-Z0-9\-]+$`)
+
+func ValidateName(name string) error {
+	if len(name) > maxNameLength {
+		return &ErrNameTooLong{
+			Name:      name,
+			MaxLength: maxNameLength,
+		}
+	}
+	if !allowedCharactersRegex.MatchString(name) {
+		return &ErrForbiddenCharacters{
+			Name:              name,
+			AllowedCharacters: allowedCharactersDescription,
+		}
+	}
+	return nil
+}

workspace/validate_test.go

@@ -0,0 +1,54 @@
+package workspace
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestValidateName(t *testing.T) {
+	type testcase struct {
+		input     string
+		errorType error
+	}
+
+	cases := []testcase{
+		{
+			input:     "name",
+			errorType: nil,
+		},
+		{
+			input:     "NAME",
+			errorType: nil,
+		},
+		{
+			input:     "name-123",
+			errorType: nil,
+		},
+		{
+			input:     "some-very-long-name",
+			errorType: &ErrNameTooLong{},
+		},
+		{
+			input:     "name_123",
+			errorType: &ErrForbiddenCharacters{},
+		},
+		{
+			input:     "neko-dugačko-ime",
+			errorType: &ErrNameTooLong{},
+		},
+		{
+			input:     "kraće-ime",
+			errorType: &ErrForbiddenCharacters{},
+		},
+	}
+
+	for _, c := range cases {
+		err := ValidateName(c.input)
+		if c.errorType == nil {
+			assert.Nil(t, err)
+		} else {
+			assert.IsType(t, c.errorType, err)
+		}
+	}
+}