fix: address review feedback on JSON STRUCTURE PR

- Sort custom name map keys for deterministic DESCRIBE output
- Check errors from json.Decoder.Token() and Decode() in snippet parser
- Add comment explaining why JsonElement uses int32 (verified vs Studio Pro)

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

Author: ako

mdl/executor/cmd_jsonstructures.go

@@ -6,6 +6,7 @@ package executor
 import (
 	"fmt"
 	"io"
+	"sort"
 	"strings"
 	"unicode"
 
@@ -98,15 +99,20 @@ func (e *Executor) describeJsonStructure(name ast.QualifiedName) error {
 	// Detect custom name mappings by comparing ExposedName to auto-generated names
 	customMappings := collectCustomNameMappings(js.Elements)
 	if len(customMappings) > 0 {
+		// Sort keys for deterministic DESCRIBE output
+		keys := make([]string, 0, len(customMappings))
+		for k := range customMappings {
+			keys = append(keys, k)
+		}
+		sort.Strings(keys)
+
 		fmt.Fprintf(e.output, "\n  CUSTOM NAME MAP (\n")
-		i := 0
-		for jsonKey, customName := range customMappings {
+		for i, jsonKey := range keys {
 			sep := ","
-			if i == len(customMappings)-1 {
+			if i == len(keys)-1 {
 				sep = ""
 			}
-			fmt.Fprintf(e.output, "    '%s' AS '%s'%s\n", jsonKey, customName, sep)
-			i++
+			fmt.Fprintf(e.output, "    '%s' AS '%s'%s\n", jsonKey, customMappings[jsonKey], sep)
 		}
 		fmt.Fprintf(e.output, "  )")
 	}

sdk/mpr/writer_jsonstructure.go

@@ -103,6 +103,9 @@ func serializeJsonStructure(js *JsonStructure) ([]byte, error) {
 	return bson.Marshal(doc)
 }
 
+// serializeJsonElement serializes a single JsonElement to BSON.
+// Note: JsonStructures$JsonElement uses int32 for numeric properties (MinOccurs, MaxOccurs, etc.),
+// unlike most other Mendix document types which use int64. Verified against Studio Pro-generated BSON.
 func serializeJsonElement(elem *JsonElement) bson.D {
 	children := bson.A{int32(2)}
 	for _, child := range elem.Children {
@@ -245,16 +248,23 @@ func (b *snippetBuilder) buildElementFromRawObject(exposedName, path, rawJSON st
 
 	// Decode with key order preserved
 	dec := json.NewDecoder(strings.NewReader(rawJSON))
-	dec.Token() // opening {
+	if _, err := dec.Token(); err != nil { // opening {
+		return elem
+	}
 	for dec.More() {
-		tok, _ := dec.Token()
+		tok, err := dec.Token()
+		if err != nil {
+			break
+		}
 		key, ok := tok.(string)
 		if !ok {
 			continue
 		}
 		// Capture the raw value to pass down for nested objects/arrays
 		var rawVal json.RawMessage
-		dec.Decode(&rawVal)
+		if err := dec.Decode(&rawVal); err != nil {
+			break
+		}
 
 		childName := childTracker.uniqueName(b.resolveExposedName(key))
 		childPath := path + "|" + key