Add reader and writer for Char

modules/core/src/main/scala/tethys/readers/instances/AllJsonReaders.scala

@@ -29,6 +29,12 @@ trait AllJsonReaders extends OptionReaders {
     }
   }
 
+  implicit lazy val charReader: JsonReader[Char] = stringReader.mapWithField{ implicit fieldName => {
+      case s if s.length == 1 => s.head
+      case s => ReaderError.wrongJson(s"Expected char value but found: $s")
+    }
+  }
+
   implicit lazy val numberReader: JsonReader[Number] = new JsonReader[Number] {
     override def read(it: TokenIterator)(implicit fieldName: FieldName): Number = {
       if(it.currentToken().isNumberValue) {

modules/core/src/main/scala/tethys/writers/instances/AllJsonWriters.scala

@@ -40,6 +40,10 @@ trait AllJsonWriters extends OptionWriters with EitherWriters {
     override def write(value: String, tokenWriter: TokenWriter): Unit = tokenWriter.writeString(value)
   }
 
+  implicit lazy val charWriter: JsonWriter[Char] = new JsonWriter[Char] {
+    override def write(value: Char, tokenWriter: TokenWriter): Unit = tokenWriter.writeString(value.toString)
+  }
+
   implicit lazy val javaIntWriter: JsonWriter[java.lang.Integer] = new JsonWriter[java.lang.Integer] {
     override def write(value: java.lang.Integer, tokenWriter: TokenWriter): Unit = tokenWriter.writeNumber(value)
   }

modules/core/src/test/scala/tethys/readers/DefaultReadersTest.scala

@@ -24,6 +24,7 @@ class DefaultReadersTest extends AnyFlatSpec {
 
   private val cases: List[(TestDefinition[_], List[TokenNode])] = List[(TestDefinition[_], List[TokenNode])](
     test("1") -> value("1"),
+    test('1') -> value("1"),
     test(1) -> value(1),
     test(1: Short) -> value(1: Short),
     test(1L) -> value(1L),

modules/core/src/test/scala/tethys/readers/JsonReaderBuilderTest.scala

@@ -63,6 +63,7 @@ class JsonReaderBuilderTest extends AnyFlatSpec with Matchers {
         .addField[Boolean]("c")
         .addField[Seq[String]]("d")
         .addField[Double]("e")
+        .addField[Char]("f")
         .addField[Option[Int]]("opt")
         .buildReader(FatClass.apply)
     }
@@ -72,13 +73,15 @@ class JsonReaderBuilderTest extends AnyFlatSpec with Matchers {
       "b" -> "s",
       "c" -> true,
       "d" -> arr("a", "b", "c"),
-      "e" -> 4
+      "e" -> 4,
+      "f" -> "c"
     )) shouldBe FatClass(
       a = 1,
       b = "s",
       c = true,
       d = Seq("a", "b", "c"),
       e = 4.0D,
+      f = 'c',
       opt = None
     )
   }
@@ -165,5 +168,6 @@ object JsonReaderBuilderTest {
                       c: Boolean,
                       d: Seq[String],
                       e: Double,
+                      f: Char,
                       opt: Option[Int])
 }

modules/core/src/test/scala/tethys/writers/DefaultWritersTest.scala

@@ -23,6 +23,7 @@ class DefaultWritersTest extends AnyFlatSpec {
 
   private val cases: List[(TestDefinition[_], List[TokenNode])] = List[(TestDefinition[_], List[TokenNode])](
     test("1") -> value("1"),
+    test('1') -> value("1"),
     test(1) -> value(1),
     test(1: Short) -> value(1: Short),
     test(1L) -> value(1L),

modules/core/src/test/scala/tethys/writers/SimpleJsonObjectWriterTest.scala

@@ -4,7 +4,7 @@ import org.scalatest.matchers.should.Matchers.{value => _, _}
 import org.scalatest.flatspec.AnyFlatSpec
 import tethys.{JsonObjectWriter, JsonWriter}
 import tethys.commons.TokenNode._
-import tethys.writers.SimpleJsonObjectWriterTest.TestData
+import tethys.writers.SimpleJsonObjectWriterTest.{CharData, TestData}
 import tethys.writers.instances.SimpleJsonObjectWriter
 import tethys.writers.tokens.SimpleTokenWriter._
 
@@ -39,10 +39,22 @@ class SimpleJsonObjectWriterTest extends AnyFlatSpec {
       "c" -> false
     )
   }
+
+  it should "write correct object with char field" in {
+    implicit val charWriter: SimpleJsonObjectWriter[CharData] = {
+      JsonWriter.obj[CharData]
+        .addField("c")(_.c)
+    }
+
+    CharData('c').asTokenList shouldBe obj(
+      "c" -> "c"
+    )
+  }
 }
 
 object SimpleJsonObjectWriterTest {
 
   case class TestData(a: Int, b: String)
+  case class CharData(c: Char)
 
 }