Add support for newJRawNumber when parsing large numbers to JsonNode (#110)

* Add support for newJRawNumber when parsing large numbers to JsonNode

* Fix exception handling

* Remove lagacy JsonNode number parser

Author: jangko

json_serialization/parser.nim

@@ -13,7 +13,7 @@ import
   ./reader_desc,
   ./lexer
 
-from json import JsonNode, JsonNodeKind, escapeJson
+from json import JsonNode, JsonNodeKind, escapeJson, parseJson
 
 export
   reader_desc
@@ -418,7 +418,7 @@ template parseObjectSkipNullFields*(r: var JsonReader, key: untyped, body: untyp
     body
   do: # error action
     r.raiseParserError()
-    
+
 template parseObjectCustomKey*(r: var JsonReader, keyAction: untyped, body: untyped) =
   mixin flavorSkipNullFields
   type
@@ -456,14 +456,23 @@ proc parseJsonNode(r: var JsonReader): JsonNode =
   of JsonValueKind.String:
     result = JsonNode(kind: JString, str: r.parseString())
   of JsonValueKind.Number:
-    var val: JsonNumber[uint64]
+    var val: string
     r.lex.scanNumber(val)
     r.checkError
-    if val.isFloat:
-      result = JsonNode(kind: JFloat, fnum: r.toFloat(val, typeof(result.fnum)))
+    when (NimMajor, NimMinor) > (1,6):
+      try:
+        # Cannot access `newJRawNumber` directly, because it's not exported.
+        # But this should produce either JInt, JFloat, or JString/Raw
+        result = parseJson(val)
+      except ValueError as exc:
+        r.raiseUnexpectedValue(exc.msg)
+      except OSError as exc:
+        raiseAssert "parseJson here should not raise OSError exception: " & exc.msg
     else:
-      result = JsonNode(kind: JInt, num:
-        r.toInt(val, typeof(result.num), JsonReaderFlag.portableInt in r.lex.flags))
+      try:
+        result = parseJson(val)
+      except Exception as exc:
+        r.raiseUnexpectedValue(exc.msg)
   of JsonValueKind.Object:
     result = JsonNode(kind: JObject)
     parseObjectImpl(r.lex, false): discard # initial action

tests/test_parser.nim

@@ -330,6 +330,14 @@ const
   }
 }
 
+"""
+
+  jsonBigNum = """
+{
+  "bignum": 9999999999999999999999999999999999999999999,
+  "float": 124.123,
+  "int": -12345
+}
 """
 
 suite "Parse to runtime dynamic structure":
@@ -345,6 +353,7 @@ suite "Parse to runtime dynamic structure":
       n["array"][0].bval == true
       n["array"][1].fnum == 567.89
       n["array"][2].str == "string in array"
+      $n["array"][2] == "\"string in array\"" # quoted string
       n["array"][3].kind == JNull
       n["array"][4].kind == JArray
       n["array"][4].len == 1
@@ -358,6 +367,7 @@ suite "Parse to runtime dynamic structure":
     check:
       n["string"].strVal == "hello world"
       n["bool"].boolVal == true
+      n["int"].numVal.integer == 789
       n["array"].len == 5
       n["array"][0].boolVal == true
       n["array"][2].strVal == "string in array"
@@ -366,14 +376,38 @@ suite "Parse to runtime dynamic structure":
       n["array"][4].len == 1
       n["object"]["def"].boolVal == false
 
+  test "parse to json node bignum":
+    var r = toReader(jsonBigNum)
+    let n = r.parseJsonNode()
+    check:
+      n["bignum"].kind == JString
+      n["bignum"].str == "9999999999999999999999999999999999999999999"
+      $n["bignum"] == "9999999999999999999999999999999999999999999" # unquoted raw string
+      n["float"].kind == JFloat
+      n["float"].fnum == 124.123
+      n["int"].kind == JInt
+      n["int"].num == -12345
+
+  test "parseValue bignum":
+    var r = toReader(jsonBigNum)
+    let n = r.parseValue(string)
+    check:
+      n["bignum"].kind == JsonValueKind.Number
+      n["bignum"].numVal.integer == "9999999999999999999999999999999999999999999"
+
+  test "parseValue bignum overflow":
+    var r = toReader(jsonBigNum)
+    expect JsonReaderError:
+      let n = r.parseValue(uint64)
+
   test "nim v2 regression #23233":
     # Nim compiler bug #23233 will prevent
     # compilation if both JsonValueRef[uint64] and JsonValueRef[string]
     # are instantiated at together.
     var r1 = toReader(jsonText)
     let n1 = r1.parseValue(uint64)
-    discard n1
+    check n1["int"].numVal.integer == 789
 
     var r2 = toReader(jsonText)
     let n2 = r2.parseValue(string)
-    discard n2
+    check n2["int"].numVal.integer == "789"