fix: JSON number type inference and mxcli new locale duplicates

Fix mendixlabs#9: Numbers like 41850.0 were inferred as Integer because Go's %v
drops the .0 suffix. Now checks the raw JSON text for a decimal point.

Fix #1: mx create-project generates duplicate locale files in nested
subdirectories under themesource/atlas_core/locales/, causing MxBuild
to crash with "An item with the same key has already been added".
Strip these duplicates after project creation.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: ako

cmd/mxcli/cmd_new.go

@@ -88,6 +88,13 @@ Examples:
 			os.Exit(1)
 		}
 
+		// Clean up duplicate locale files that mx create-project generates.
+		// MxBuild's AtlasPlugin.LoadTranslations crashes with "An item with the same
+		// key has already been added" when duplicate translation.json files exist.
+		if removed := cleanupDuplicateLocaleFiles(absDir); removed > 0 {
+			fmt.Printf("  Cleaned %d duplicate locale file(s)\n", removed)
+		}
+
 		// Verify .mpr was created — mx create-project names the file after --app-name
 		mprPath := filepath.Join(absDir, appName+".mpr")
 		if _, err := os.Stat(mprPath); os.IsNotExist(err) {
@@ -153,6 +160,51 @@ Examples:
 	},
 }
 
+// cleanupDuplicateLocaleFiles removes duplicate locale files that mx create-project
+// generates in themesource/atlas_core/. MxBuild crashes when multiple translation.json
+// files map to the same locale key (e.g., "en-US").
+//
+// Studio Pro-created projects have locale files only at:
+//   themesource/atlas_core/locales/<locale>/translation.json
+//
+// mx create-project additionally creates duplicates in nested subdirectories
+// (e.g., locales/en-US/atlas_core/locales/en-US/translation.json).
+// We keep only the top-level files and remove any deeper duplicates.
+func cleanupDuplicateLocaleFiles(projectDir string) int {
+	localesDir := filepath.Join(projectDir, "themesource", "atlas_core", "locales")
+	if _, err := os.Stat(localesDir); os.IsNotExist(err) {
+		return 0
+	}
+
+	removed := 0
+	// Walk locale directories (en-US, nl-NL, etc.)
+	entries, err := os.ReadDir(localesDir)
+	if err != nil {
+		return 0
+	}
+	for _, entry := range entries {
+		if !entry.IsDir() {
+			continue
+		}
+		localeDir := filepath.Join(localesDir, entry.Name())
+		// Check for nested subdirectories that duplicate the locale
+		subEntries, err := os.ReadDir(localeDir)
+		if err != nil {
+			continue
+		}
+		for _, sub := range subEntries {
+			if sub.IsDir() {
+				// Any subdirectory under a locale dir is a duplicate tree
+				dupPath := filepath.Join(localeDir, sub.Name())
+				if err := os.RemoveAll(dupPath); err == nil {
+					removed++
+				}
+			}
+		}
+	}
+	return removed
+}
+
 func init() {
 	newCmd.Flags().String("version", "", "Mendix version (e.g., 11.8.0) — required")
 	newCmd.Flags().String("output-dir", "", "Output directory (default: ./<app-name>)")

sdk/mpr/writer_jsonstructure.go

@@ -302,7 +302,8 @@ func (b *snippetBuilder) buildElementFromRawValue(exposedName, path, jsonKey str
 		}
 		return buildValueElement(exposedName, path, primitiveType, fmt.Sprintf("%q", v))
 	case float64:
-		if v == math.Trunc(v) && !strings.Contains(fmt.Sprintf("%v", v), ".") {
+		// Check the raw JSON text for a decimal point — Go's %v drops ".0" from 41850.0
+		if v == math.Trunc(v) && !strings.Contains(trimmed, ".") {
 			return buildValueElement(exposedName, path, "Integer", fmt.Sprintf("%v", int64(v)))
 		}
 		return buildValueElement(exposedName, path, "Decimal", fmt.Sprintf("%v", v))