diff --git a/project/WeePicklePlugin.scala b/project/WeePicklePlugin.scala
index 866b2bb0..dbd34c92 100644
--- a/project/WeePicklePlugin.scala
+++ b/project/WeePicklePlugin.scala
@@ -14,8 +14,8 @@ object WeePicklePlugin extends AutoPlugin {
 
     val scala211 = "2.11.12"
     val scala212 = "2.12.12"
-    val scala213 = "2.13.5"
-    val scala3 = "3.0.1"
+    val scala213 = "2.13.7"
+    val scala3 = "3.1.0"
     val supportedScala2Versions = Seq(scala211, scala212, scala213)
     val supportedScalaVersions = supportedScala2Versions :+ scala3
 
@@ -119,6 +119,14 @@ object WeePicklePlugin extends AutoPlugin {
 
       builder.result()
     },
+    Test / scalacOptions ++= {
+      scalaBinaryVersion.value match {
+        case "3" => Seq(
+          "-Wconf:cat=deprecation:info" // scalacheck uses Stream
+        )
+        case _ => Nil
+      }
+    },
     testFrameworks += new TestFramework("utest.runner.Framework"),
   )
 }
diff --git a/weejson-jackson/test/resources/empty.json b/weejson-jackson/test/resources/empty.json
deleted file mode 100644
index e69de29b..00000000
diff --git a/weejson-jackson/test/scala/com/rallyhealth/weejson/v1/jackson/GenValue.scala b/weejson-jackson/test/scala/com/rallyhealth/weejson/v1/jackson/GenValue.scala
deleted file mode 100644
index 7c1d511c..00000000
--- a/weejson-jackson/test/scala/com/rallyhealth/weejson/v1/jackson/GenValue.scala
+++ /dev/null
@@ -1,53 +0,0 @@
-package com.rallyhealth.weejson.v1.jackson
-
-import com.rallyhealth.weejson.v1._
-import org.scalacheck.{Arbitrary, Gen}
-
-import scala.collection.mutable.ArrayBuffer
-
-trait GenValue {
-
-  def genArray(depth: Int): Gen[Arr] = {
-    for {
-      n <- Gen.chooseNum(0, 10)
-      arr <- Gen.containerOfN[ArrayBuffer, Value](n, genValue(depth)).map(Arr(_))
-    } yield arr
-  }
-
-  def genObject(depth: Int): Gen[Obj] =
-    for {
-      n <- Gen.chooseNum(0, 10)
-      genKV = for {
-        k <- Gen.alphaNumStr
-        v <- genValue(depth)
-      } yield k -> v
-      obj <- Gen.buildableOfN[Map[String, Value], (String, Value)](n, genKV).map(Obj.from)
-    } yield obj
-
-  def genValue(depth: Int): Gen[Value] = {
-    val nonRecursive = List(
-      Gen.alphaNumStr.map(Str),
-      Arbitrary.arbitrary[Double].map(Num(_)),
-      Arbitrary.arbitrary[Boolean].map(Bool(_)),
-      Gen.const(Null)
-    )
-
-    val maybeRecursive: List[Gen[Value]] = depth match {
-      case 0 => Nil
-      case _ =>
-        List(
-          genArray(depth - 1),
-          genObject(depth - 1)
-        )
-    }
-
-    val generators: List[Gen[Value]] = nonRecursive ++ maybeRecursive
-    Gen.oneOf(generators(0), generators(1), generators.drop(2): _*) // scalacheck API :\
-  }
-
-  implicit val arbJsValue: Arbitrary[Value] = Arbitrary {
-    Gen
-      .chooseNum(0, 5)
-      .flatMap(depth => genValue(depth))
-  }
-}
diff --git a/weejson-jackson/test/scala/com/rallyhealth/weejson/v1/jackson/JsonGeneratorOutputStreamSpec.scala b/weejson-jackson/test/scala/com/rallyhealth/weejson/v1/jackson/JsonGeneratorOutputStreamSpec.scala
deleted file mode 100644
index d9a14947..00000000
--- a/weejson-jackson/test/scala/com/rallyhealth/weejson/v1/jackson/JsonGeneratorOutputStreamSpec.scala
+++ /dev/null
@@ -1,42 +0,0 @@
-package com.rallyhealth.weejson.v1.jackson
-
-import java.io.StringWriter
-import java.nio.charset.StandardCharsets.UTF_8
-
-import com.rallyhealth.weejson.v1.jackson.DefaultJsonFactory.Instance
-import com.rallyhealth.weejson.v1.{Value, WeeJson}
-import org.scalactic.TypeCheckedTripleEquals
-import org.scalatest.{FreeSpec, LoneElement, Matchers}
-import org.scalatestplus.scalacheck.ScalaCheckDrivenPropertyChecks
-
-class JsonGeneratorOutputStreamSpec
-    extends FreeSpec
-    with Matchers
-    with ScalaCheckDrivenPropertyChecks
-    with GenValue
-    with LoneElement
-    with TypeCheckedTripleEquals {
-
-  override implicit val generatorDrivenConfig: PropertyCheckConfiguration = PropertyCheckConfiguration(
-    minSuccessful = 500
-  )
-
-  "like WeeJson" in {
-    forAll { input: Value =>
-      val result: Value = {
-        var output = Seq.newBuilder[Value]
-        val writer = new StringWriter
-        val generator = Instance.createGenerator(writer)
-        val out = new JsonGeneratorOutputStream(generator)
-
-        val strInput = WeeJson.write(input)
-        out.write(strInput.getBytes(UTF_8))
-        out.close()
-
-        WeeJson.read(writer.toString)
-      }
-
-      result shouldBe input
-    }
-  }
-}
diff --git a/weejson-jackson/test/scala/com/rallyhealth/weejson/v1/jackson/WeeJacksonSpec.scala b/weejson-jackson/test/scala/com/rallyhealth/weejson/v1/jackson/WeeJacksonSpec.scala
deleted file mode 100644
index 239de11d..00000000
--- a/weejson-jackson/test/scala/com/rallyhealth/weejson/v1/jackson/WeeJacksonSpec.scala
+++ /dev/null
@@ -1,47 +0,0 @@
-package com.rallyhealth.weejson.v1.jackson
-
-import java.io.{File, StringWriter}
-
-import com.fasterxml.jackson.core.io.JsonEOFException
-import com.rallyhealth.weejson.v1._
-import com.rallyhealth.weejson.v1.jackson.DefaultJsonFactory.Instance
-import org.scalactic.TypeCheckedTripleEquals
-import org.scalatest.{FreeSpec, Matchers}
-import org.scalatestplus.scalacheck.ScalaCheckDrivenPropertyChecks
-
-class WeeJacksonSpec
-    extends FreeSpec
-    with Matchers
-    with ScalaCheckDrivenPropertyChecks
-    with GenValue
-    with TypeCheckedTripleEquals {
-
-  override implicit val generatorDrivenConfig: PropertyCheckConfiguration = PropertyCheckConfiguration(
-    minSuccessful = 500
-  )
-  "parse" - {
-    "like WeeJson" in forAll { value: Value =>
-      val str = WeeJson.write(value)
-      FromJson(str).transform(Value) should ===(value)
-    }
-  }
-
-  "visitor" - {
-    "like WeeJson.write" in {
-      forAll { value: Value =>
-        val writer = new StringWriter()
-        value.transform(JsonRenderer(Instance.createGenerator(writer)))
-        writer.toString should ===(value.transform(StringRenderer()).toString)
-      }
-    }
-  }
-
-  "empty file input" - {
-    "to required" in {
-      val file = new File(getClass.getResource("/empty.json").getPath)
-      intercept[JsonEOFException] {
-        FromJson(file).transform(Value)
-      }
-    }
-  }
-}
diff --git a/weejson/src/test/scala/com/rallyhealth/weejson/v1/GenBufferedValue.scala b/weejson/src/test/scala/com/rallyhealth/weejson/v1/GenBufferedValue.scala
index 1ae863dc..e04ad7a7 100644
--- a/weejson/src/test/scala/com/rallyhealth/weejson/v1/GenBufferedValue.scala
+++ b/weejson/src/test/scala/com/rallyhealth/weejson/v1/GenBufferedValue.scala
@@ -1,11 +1,11 @@
 package com.rallyhealth.weejson.v1
 
-import org.scalacheck.{Arbitrary, Gen}
+import org.scalacheck.{Arbitrary, Gen, Shrink}
 
 import scala.collection.mutable.ArrayBuffer
 
 trait GenBufferedValue {
-  import BufferedValue.{Arr, Obj, Str, Bool, Null, AnyNum}
+  import com.rallyhealth.weejson.v1.BufferedValue._
 
   def genArray(depth: Int): Gen[Arr] = {
     for {
@@ -52,6 +52,17 @@ trait GenBufferedValue {
   }
 
   implicit val arbNum: Arbitrary[AnyNum] = Arbitrary {
-    Arbitrary.arbitrary[Double].map(BigDecimal(_)).map(AnyNum(_))
+    Arbitrary.arbitrary[Double].map(BigDecimal(_)).map(AnyNum(_)) // TODO open to all BigDecimals after #102
+  }
+
+  implicit val shrinkValue: Shrink[BufferedValue] = Shrink[BufferedValue] {
+    case Obj(map) => Shrink.shrink(map).map(Obj(_))
+    case Arr(buf) => Shrink.shrink(buf).map(Arr(_))
+    case NumDouble(d) => NumLong(d.longValue) +: Shrink.shrink(d).map(NumDouble(_))
+    case NumLong(long) => Shrink.shrink(long).map(NumLong(_))
+    case Str(s) => Shrink.shrink(s).map(Str(_))
+    case Timestamp(s) => Shrink.shrink(s).map(Timestamp(_))
+    case Ext(tag, bytes) => Shrink.shrink(bytes).map(Ext(tag, _))
+    case _ => Stream.empty
   }
 }
diff --git a/weejson/src/test/scala/com/rallyhealth/weejson/v1/GenValue.scala b/weejson/src/test/scala/com/rallyhealth/weejson/v1/GenValue.scala
index daf49e07..f5ed438e 100644
--- a/weejson/src/test/scala/com/rallyhealth/weejson/v1/GenValue.scala
+++ b/weejson/src/test/scala/com/rallyhealth/weejson/v1/GenValue.scala
@@ -1,7 +1,7 @@
 package com.rallyhealth.weejson.v1
 
 import com.rallyhealth.weejson.v1._
-import org.scalacheck.{Arbitrary, Gen}
+import org.scalacheck.{Arbitrary, Gen, Shrink}
 
 import scala.collection.mutable.ArrayBuffer
 
@@ -54,4 +54,12 @@ trait GenValue {
   implicit val arbNum: Arbitrary[Num] = Arbitrary {
     Arbitrary.arbitrary[Double].map(Num(_))
   }
+
+  implicit val shrinkValue: Shrink[Value] = Shrink[Value] {
+    case Obj(map) => Shrink.shrink(map).map(Obj(_))
+    case Arr(buf) => Shrink.shrink(buf).map(Arr(_))
+    case Num(bd) => Shrink.shrink(bd).map(Num(_))
+    case Str(s) => Shrink.shrink(s).map(Str(_))
+    case _ => Stream.empty
+  }
 }
diff --git a/weepickle-tests/src/test/scala/com/rallyhealth/weepickle/v1/MaxDepthVisitor.scala b/weepickle-tests/src/test/scala/com/rallyhealth/weepickle/v1/MaxDepthVisitor.scala
new file mode 100644
index 00000000..65c44afc
--- /dev/null
+++ b/weepickle-tests/src/test/scala/com/rallyhealth/weepickle/v1/MaxDepthVisitor.scala
@@ -0,0 +1,46 @@
+package com.rallyhealth.weepickle.v1
+
+import com.rallyhealth.weepickle.v1.core.{ArrVisitor, NoOpVisitor, ObjArrVisitor, ObjVisitor, Visitor}
+
+/**
+  * Returns the max depth encountered.
+  * Useful for creating valid test inputs that can be sent to a parser that throws at high depth.
+  */
+class MaxDepthVisitor extends NoOpVisitor[Int](0) {
+
+  private[this] var maxDepth = 0
+  private[this] var currentDepth = 0
+
+  private def inc() = {
+    currentDepth += 1
+    maxDepth = math.max(maxDepth, currentDepth)
+  }
+
+  private def dec() = {
+    currentDepth -= 1
+  }
+
+  private trait ObjArrBase {
+    self: ObjArrVisitor[Any, Int] =>
+
+    override def subVisitor: Visitor[_, _] = {
+      inc()
+      MaxDepthVisitor.this.map(_ => maxDepth)
+    }
+
+    override def visitValue(v: Any): Unit = dec()
+
+    override def visitEnd(): Int = maxDepth
+  }
+
+  override def visitObject(length: Int): ObjVisitor[Any, Int] = new ObjVisitor[Any, Int] with ObjArrBase {
+    override def visitKey(): Visitor[_, _] = {
+      inc()
+      NoOpVisitor
+    }
+
+    override def visitKeyValue(v: Any): Unit = dec()
+  }
+
+  override def visitArray(length: Int): ArrVisitor[Any, Int] = new ArrVisitor[Any, Int] with ObjArrBase
+}
diff --git a/weepickle-tests/src/test/scala/com/rallyhealth/weepickle/v1/ParserSpec.scala b/weepickle-tests/src/test/scala/com/rallyhealth/weepickle/v1/ParserSpec.scala
new file mode 100644
index 00000000..24d8b55f
--- /dev/null
+++ b/weepickle-tests/src/test/scala/com/rallyhealth/weepickle/v1/ParserSpec.scala
@@ -0,0 +1,68 @@
+package com.rallyhealth.weepickle.v1
+
+import com.rallyhealth.weejson.v1.jackson.{FromJson, ToJson, ToPrettyJson}
+import com.rallyhealth.weejson.v1.{BufferedValue, GenBufferedValue}
+import com.rallyhealth.weepickle.v1.core.FromInput
+import org.scalactic.TypeCheckedTripleEquals
+import org.scalatest.freespec.AnyFreeSpec
+import org.scalatestplus.scalacheck.ScalaCheckPropertyChecks
+
+import java.io.{ByteArrayInputStream, StringReader}
+import java.nio.file.Files
+import scala.language.{existentials, implicitConversions}
+
+abstract class ParserSpec(parse: Array[Byte] => FromInput, depthLimit: Int = 100)
+  extends AnyFreeSpec
+    with ScalaCheckPropertyChecks
+    with GenBufferedValue
+    with TypeCheckedTripleEquals {
+
+  import com.rallyhealth.weejson.v1.BufferedValue._
+  import com.rallyhealth.weejson.v1.BufferedValueOps._
+
+  private implicit def toBytes(s: String): Array[Byte] = s.getBytes
+
+  "roundtrip" in testJson()
+  "deep arr" in testDepth(Arr(_))
+  "deep obj" in testDepth(b => Obj("k" -> b))
+
+  private def testJson(tweak: BufferedValue => BufferedValue = identity) = {
+    forAll { (b: BufferedValue) =>
+      val value = tweak(b)
+      val expected = value.transform(ToJson.string)
+
+      def testInput(s: Array[Byte]) = assert(parse(s).transform(ToJson.string) === expected)
+
+      testInput(expected)
+      testInput(s"\n $expected \n ")
+      testInput(value.transform(ToPrettyJson.bytes))
+
+      assert(parse(expected.getBytes()).transform(BufferedValue.Builder) === value)
+    }
+  }
+
+  private def testDepth(f: BufferedValue => BufferedValue) = {
+    testJson { in =>
+      val depth = in.transform(new MaxDepthVisitor)
+      val numPads = math.max(depthLimit - depth, 0)
+      (0 to numPads).foldLeft(in)((p, _) => f(p))
+    }
+  }
+}
+
+class FromJsonBytesSpec extends ParserSpec(FromJson(_))
+
+class FromJsonStringSpec extends ParserSpec(b => FromJson(new String(b)))
+
+class FromJsonInputStreamSpec extends ParserSpec(b => FromJson(new ByteArrayInputStream(b)))
+
+class FromJsonReaderSpec extends ParserSpec(b => FromJson(new StringReader(new String(b))))
+
+class FromJsonPathSpec extends ParserSpec(
+  b => FromJson(Files.write(Files.createTempFile("FromJsonPathSpec", ".json"), b))
+)
+
+class FromJsonFileSpec extends ParserSpec(
+  b => FromJson(Files.write(Files.createTempFile("FromJsonFileSpec", ".json"), b).toFile)
+)
+