Add support and tests for Option and reference types

json_serialization/reader.nim

@@ -102,6 +102,12 @@ proc skipToken(r: var JsonReader, tk: TokKind) =
   r.requireToken tk
   r.lexer.next()
 
+proc allocPtr[T](p: var ptr T) =
+  p = create(T)
+
+proc allocPtr[T](p: var ref T) =
+  p = new(T)
+
 proc readValue*(r: var JsonReader, value: var auto) =
   mixin readValue
 
@@ -119,6 +125,14 @@ proc readValue*(r: var JsonReader, value: var auto) =
     else: r.raiseUnexpectedToken etBool
     r.lexer.next()
 
+  elif value is ref|ptr:
+    if tok == tkNull:
+      value = nil
+      r.lexer.next()
+    else:
+      allocPtr value
+      value[] = readValue(r, type(value[]))
+
   elif value is enum:
     case tok
     of tkString:

json_serialization/std/net.nim

@@ -1,5 +1,5 @@
 import std/net, ../../json_serialization.nim
-export json_serialization
+export net
 
 proc writeValue*(writer: var JsonWriter, value: Port) =
   writeValue(writer, uint16 value)

json_serialization/std/options.nim

@@ -0,0 +1,17 @@
+import std/options, ../../json_serialization/[reader, writer, lexer]
+export options
+
+proc writeValue*(writer: var JsonWriter, value: Option) =
+  if value.isSome:
+    writer.writeValue value.get
+  else:
+    writer.writeValue JsonString("null")
+
+proc readValue*[T](reader: var JsonReader, value: var Option[T]) =
+  let tok = reader.lexer.tok
+  if tok == tkNull:
+    reset value
+    reader.lexer.next()
+  else:
+    value = some reader.readValue(T)
+

tests/test_serialization.nim

@@ -1,7 +1,8 @@
 import
-  strutils, options, unittest,
+  strutils, unittest,
   serialization/testing/generic_suite,
-  ../json_serialization, ./utils
+  ../json_serialization, ./utils,
+  ../json_serialization/std/options
 
 type
   Meter = distinct int
@@ -20,7 +21,10 @@ type
   Bar = object
     sf: seq[Foo]
     z: ref Simple
-    # o: Option[Simple]
+
+  HoldsOption = object
+    r: ref Simple
+    o: Option[Simple]
 
   HoldsArray = object
     data: seq[int]
@@ -37,8 +41,22 @@ template reject(code) =
 
 borrowSerialization(Meter, int)
 
+proc `==`(lhs, rhs: Meter): bool =
+  int(lhs) == int(rhs)
+
+proc `==`(lhs, rhs: ref Simple): bool =
+  if lhs.isNil: return rhs.isNil
+  if rhs.isNil: return false
+  return lhs[] == rhs[]
+
 executeReaderWriterTests Json
 
+proc newSimple(x: int, y: string, d: Meter): ref Simple =
+  new result
+  result.x = x
+  result.y = y
+  result.distance = d
+
 when false:
   # The compiler cannot handle this check at the moment
   # {.fatal.} seems fatal even in `compiles` context
@@ -111,3 +129,12 @@ suite "toJson tests":
     check:
       r.toJSON == """{"type":"uint8"}"""
       r == Json.decode("""{"type":"uint8"}""", Reserved)
+
+  test "Option types":
+    let
+      h1 = HoldsOption(o: some Simple(x: 1, y: "2", distance: Meter(3)))
+      h2 = HoldsOption(r: newSimple(1, "2", Meter(3)))
+
+    Json.roundtripTest h1, """{"r":null,"o":{"x":1,"y":"2","distance":3}}"""
+    Json.roundtripTest h2, """{"r":{"x":1,"y":"2","distance":3},"o":null}"""
+