refactor: simplify project directory name normalization

internal/pkg/create/create.go

@@ -171,21 +171,20 @@ func Create(ctx context.Context, clients *shared.ClientFactory, createArgs Creat
 // multiDashRe matches consecutive dashes.
 var multiDashRe = regexp.MustCompile(`-{2,}`)
 
-// nonAlphanumericRe matches any character that is not a lowercase letter, digit, or dash.
-var nonAlphanumericRe = regexp.MustCompile(`[^a-z0-9-]+`)
+// nonPathSafeRe matches characters that are not safe for file paths (not alphanumeric, dash, underscore, or dot).
+var nonPathSafeRe = regexp.MustCompile(`[^a-zA-Z0-9._-]+`)
 
-// getAppDirName will validate and return the app's directory name in kebab-case
+// getAppDirName will validate and return the app's directory name safe for file paths
 func getAppDirName(appName string) (string, error) {
 	if len(appName) <= 0 {
 		return "", fmt.Errorf("app name is required")
 	}
 
-	// Normalize to a variation of kebab-case: replace non-alphanumeric with dashes, collapse, and trim
+	// Normalize: trim whitespace, replace spaces with dashes, remove unsafe characters
 	appName = strings.TrimSpace(appName)
-	appName = strings.ToLower(appName)
-	appName = nonAlphanumericRe.ReplaceAllString(appName, "-")
+	appName = strings.ReplaceAll(appName, " ", "-")
+	appName = nonPathSafeRe.ReplaceAllString(appName, "")
 	appName = multiDashRe.ReplaceAllString(appName, "-")
-	appName = strings.Trim(appName, "-")
 
 	if len(appName) == 0 {
 		return "", fmt.Errorf("app name must contain at least one alphanumeric character")
@@ -198,7 +197,7 @@ func getAppDirName(appName string) (string, error) {
 	return appName, nil
 }
 
-// parseAppPath splits user input into a directory path (with kebab-cased basename)
+// parseAppPath splits user input into a directory path (with path-safe basename)
 // and a display name (the raw basename preserving original casing/spacing).
 func parseAppPath(input string) (appPath string, displayName string, err error) {
 	input = strings.TrimSpace(input)

internal/pkg/create/create_test.go

@@ -58,29 +58,37 @@ func TestGetProjectDirectoryName(t *testing.T) {
 			input:    "  my-app  ",
 			expected: "my-app",
 		},
-		"uppercase converted to lowercase": {
+		"uppercase preserved with spaces replaced": {
 			input:    "My Slack App",
-			expected: "my-slack-app",
+			expected: "My-Slack-App",
 		},
-		"mixed case normalized": {
+		"mixed case preserved": {
 			input:    "My-Slack-App",
-			expected: "my-slack-app",
+			expected: "My-Slack-App",
 		},
-		"special characters replaced with dashes": {
-			input:    "my_app!@#test",
-			expected: "my-app-test",
+		"unsafe characters removed": {
+			input:    "my_App!@#Test",
+			expected: "my_AppTest",
 		},
-		"consecutive special characters collapsed to single dash": {
+		"consecutive dashes collapsed to single dash": {
 			input:    "my---app",
 			expected: "my-app",
 		},
-		"leading and trailing special characters trimmed": {
+		"leading and trailing dashes preserved": {
 			input:    "---my-app---",
-			expected: "my-app",
+			expected: "-my-app-",
+		},
+		"underscores preserved": {
+			input:    "my_app",
+			expected: "my_app",
+		},
+		"dots preserved": {
+			input:    "my.app",
+			expected: "my.app",
 		},
-		"dots converted to dashes": {
+		"leading dots preserved": {
 			input:    ".my-app",
-			expected: "my-app",
+			expected: ".my-app",
 		},
 		"only special characters returns error": {
 			input:    "!!!",
@@ -92,7 +100,7 @@ func TestGetProjectDirectoryName(t *testing.T) {
 		},
 		"complex mixed input": {
 			input:    "  My Cool App! (v2)  ",
-			expected: "my-cool-app-v2",
+			expected: "My-Cool-App-v2",
 		},
 	}
 	for name, tc := range tests {
@@ -122,7 +130,7 @@ func TestParseAppPath(t *testing.T) {
 		},
 		"name with spaces": {
 			input:           "My Cool App",
-			expectedPath:    "my-cool-app",
+			expectedPath:    "My-Cool-App",
 			expectedDisplay: "My Cool App",
 		},
 		"relative path with simple name": {
@@ -132,7 +140,7 @@ func TestParseAppPath(t *testing.T) {
 		},
 		"relative path with spaced name": {
 			input:           "path/to/My App",
-			expectedPath:    filepath.Join("path", "to", "my-app"),
+			expectedPath:    filepath.Join("path", "to", "My-App"),
 			expectedDisplay: "My App",
 		},
 		"dot-prefixed path": {
@@ -152,7 +160,7 @@ func TestParseAppPath(t *testing.T) {
 		},
 		"uppercase in nested path": {
 			input:           "projects/My Slack App",
-			expectedPath:    filepath.Join("projects", "my-slack-app"),
+			expectedPath:    filepath.Join("projects", "My-Slack-App"),
 			expectedDisplay: "My Slack App",
 		},
 		"trailing slash is trimmed": {