Fix UnknownFObjectParser and add unit tests

src/foam/lib/json/UnknownFObjectParser.java

@@ -6,9 +6,7 @@
 package foam.lib.json;
 
 import foam.lib.parse.*;
-import foam.lang.X;
 
-// TODO: Fix, doesn't parse {key:"}"}, use proper JSON parser
 public class UnknownFObjectParser
   implements Parser
 {

src/foam/lib/json/UnknownFObjectParserTest.js

@@ -0,0 +1,58 @@
+/**
+ * @license
+ * Copyright 2025 The FOAM Authors. All Rights Reserved.
+ * http://www.apache.org/licenses/LICENSE-2.0
+ */
+
+foam.CLASS({
+  package: 'foam.lib.json',
+  name: 'UnknownFObjectParserTest',
+  extends: 'foam.core.test.Test',
+
+  javaImports: [
+    'foam.lib.parse.*'
+  ],
+
+  methods: [
+    {
+      name: 'runTest',
+      javaCode: `
+        // setup parser
+        var parser  = UnknownFObjectParser.instance();
+        var psx     = new ParserContextImpl();
+
+        // parse json
+        var input = "{\\"key\\":\\"value\\",\\"key2\\":true,\\"key3\\":null,\\"key4\\":{\\"foo\\":\\"bar\\"},\\"key5\\":[true,false,null,\\"text\\",1.23]}";
+        var ps = new StringPStream(input);
+        ps = (StringPStream) ps.apply(parser, psx);
+        test ( ps != null && ((UnknownFObject) ps.value()).getJson().equals(input), "Parsed json, input:" + input );
+
+        // parse empty json
+        var input2 = "{}";
+        ps = new StringPStream(input2);
+        ps = (StringPStream) ps.apply(parser, psx);
+        test ( ps != null && ((UnknownFObject) ps.value()).getJson().equals(input2), "Parsed empty json, input:" + input2 );
+
+        // parse json with un-quoted key
+        var input3 = "{key:\\"}\\"}";
+        ps = new StringPStream(input3);
+        ps = (StringPStream) ps.apply(parser, psx);
+        test ( ps != null && ((UnknownFObject) ps.value()).getJson().equals("{\\"key\\":\\"}\\"}"), "Parsed json with un-quoted key, input:" + input3 );
+
+        // parse json with comment line before key:value
+        var input4 = "{//comment1 \\n key:\\"1\\"," + "//comment2 \\n key2:\\"2\\"}";
+        var input4_print = "{//comment1 \\\\n key:\\"1\\"," + "//comment2 \\\\n key2:\\"2\\"}";
+        ps = new StringPStream(input4);
+        ps = (StringPStream) ps.apply(parser, psx);
+        test ( ps != null && ((UnknownFObject) ps.value()).getJson().equals("{\\"key\\":\\"1\\",\\"key2\\":\\"2\\"}"), "Parsed json with comment above properties, input:" + input4_print );
+
+        // parse empty json with just comments
+        var input5 = "{// comment1 \\n  // comment2 \\n}";
+        var input5_print = "{// comment1 \\\\n  // comment2 \\\\n}";
+        ps = new StringPStream(input5);
+        ps = (StringPStream) ps.apply(parser, psx);
+        test ( ps != null && ((UnknownFObject) ps.value()).getJson().equals("{}"), "Parsed empty json with just comment, input:" + input5_print );
+      `
+    }
+  ]
+});

src/foam/lib/json/UnknownObjectParser.java

@@ -26,7 +26,7 @@ public UnknownObjectParser() {
 
         public PStream parse(PStream ps, ParserContext x) {
           ps = ps.apply(delegate, x);
-          if ( ps == null) return null;
+          if ( ps == null ) return null;
           return ps.setValue("{" + ps.value() + "}");
         }
       });

src/foam/lib/json/UnknownPropertiesParser.java

@@ -7,23 +7,34 @@
 package foam.lib.json;
 
 import foam.lib.parse.*;
+import foam.util.SafetyUtil;
 
 public class UnknownPropertiesParser
   extends ProxyParser
 {
   public UnknownPropertiesParser() {
     super(new Parser() {
-      Parser delegate = new Repeat(new Seq1(2, new Optional(CommentParser.create()), Whitespace.instance(), new Alt(new UnknownKeyValueParser0(), CommentParser.create())),
-      Literal.create(","));
+      Parser delegate = new Repeat(
+        new Seq1(1,
+          new Optional(CommentParser.create()),
+          new Alt(new UnknownKeyValueParser0(), Whitespace.instance())
+        ), ",");
+
       public PStream parse(PStream ps, ParserContext x) {
         ps = ps.apply(delegate, x);
         if ( ps == null ) return null;
+
         Object[] objs = (Object[]) ps.value();
         StringBuilder res = new StringBuilder();
         for ( int i = 0 ; i < objs.length ; i++ ) {
-          res.append(objs[i].toString());
-          if ( i < objs.length - 1) {
-            res.append(',');
+          if ( objs[i] instanceof String str ) {
+            // Do not include empty string and invalid key-value pair
+            if ( SafetyUtil.isEmpty(str) || str.indexOf(":") == -1 ) continue;
+
+            res.append(str);
+            if ( i < objs.length - 1) {
+              res.append(',');
+            }
           }
         }
         return ps.setValue(res.toString());

src/foam/lib/json/tests.jrl

@@ -2,3 +2,4 @@ p({"class":"foam.lib.json.ClassReferenceParserTest","id":"ClassReferenceParserTe
 p({"class":"foam.lib.json.PropertyReferenceParserTest","id":"PropertyReferenceParserTest","description":"Tests the Property reference parser"})
 p({"class":"foam.lib.json.StringToStringArrayParserTest","id":"StringToStringArrayParserTest","description":"Tests string data to string array parser"})
 p({"class":"foam.lib.json.RawMapParserTest","id":"RawMapParserTest","description":"Tests raw map parser"})
+p({"class":"foam.lib.json.UnknownFObjectParserTest","id":"UnknownFObjectParserTest","description":"Tests unknown fobject parser"})

src/pom.js

@@ -1161,6 +1161,7 @@ foam.POM({
     { name: "foam/demos/u2/AllViews",                                 flags: "web" },
     { name: "foam/lib/json/StringToStringArrayParserTest",            flags: "js&test|java&test" },
     { name: "foam/lib/json/RawMapParserTest",                         flags: "js&test|java&test" },
+    { name: "foam/lib/json/UnknownFObjectParserTest",                 flags: "js&test|java&test" },
     { name: "foam/audio/Speak",                                       flags: "web" },
     { name: "foam/audio/Beep",                                        flags: "web" }
   ],