From e66d17e7cce2eca95404aa63f3cf6ea6ac1e7043 Mon Sep 17 00:00:00 2001
From: Raman Sarvaria <raman.sarvaria@indexexchange.com>
Date: Fri, 29 Apr 2022 11:15:04 -0400
Subject: [PATCH] Initial attempt to update JSON parsing to allow for optional
 numeric boolean values.

---
 .../scala/scalapb/json4s/JsonFormat.scala     | 21 ++++++++++++++---
 .../scala/scalapb/json4s/JsonFormatSpec.scala | 23 +++++++++++++++++++
 2 files changed, 41 insertions(+), 3 deletions(-)

diff --git a/src/main/scala/scalapb/json4s/JsonFormat.scala b/src/main/scala/scalapb/json4s/JsonFormat.scala
index 80771bd7..371548ec 100644
--- a/src/main/scala/scalapb/json4s/JsonFormat.scala
+++ b/src/main/scala/scalapb/json4s/JsonFormat.scala
@@ -9,7 +9,7 @@ import com.google.protobuf.timestamp.Timestamp
 import scalapb.json4s.JsonFormat.GenericCompanion
 import scalapb._
 import org.json4s.JsonAST._
-import org.json4s.{Reader, Writer, MappingException}
+import org.json4s.{MappingException, Reader, Writer}
 
 import scala.collection.mutable
 import scala.collection.concurrent.TrieMap
@@ -464,6 +464,7 @@ object Parser {
   private final case class ParserConfig(
       isIgnoringUnknownFields: Boolean,
       isIgnoringOverlappingOneofFields: Boolean,
+      areNumericBooleanValuesAllowed: Boolean,
       mapEntriesAsKeyValuePairs: Boolean,
       formatRegistry: FormatRegistry,
       typeRegistry: TypeRegistry
@@ -476,6 +477,7 @@ class Parser private (config: Parser.ParserConfig) {
       Parser.ParserConfig(
         isIgnoringUnknownFields = false,
         isIgnoringOverlappingOneofFields = false,
+        areNumericBooleanValuesAllowed = false,
         mapEntriesAsKeyValuePairs = false,
         JsonFormat.DefaultRegistry,
         TypeRegistry.empty
@@ -495,6 +497,7 @@ class Parser private (config: Parser.ParserConfig) {
       Parser.ParserConfig(
         isIgnoringUnknownFields = false,
         isIgnoringOverlappingOneofFields = false,
+        areNumericBooleanValuesAllowed = false,
         mapEntriesAsKeyValuePairs = false,
         formatRegistry,
         typeRegistry
@@ -507,6 +510,9 @@ class Parser private (config: Parser.ParserConfig) {
   def ignoringOverlappingOneofFields: Parser =
     new Parser(config.copy(isIgnoringOverlappingOneofFields = true))
 
+  def allowNumericBooleanValues: Parser =
+    new Parser(config.copy(areNumericBooleanValuesAllowed = true))
+
   def mapEntriesAsKeyValuePairs: Parser =
     new Parser(config.copy(mapEntriesAsKeyValuePairs = true))
 
@@ -714,7 +720,8 @@ class Parser private (config: Parser.ParserConfig) {
           value,
           throw new JsonFormatException(
             s"Unexpected value ($value) for field ${fd.name} of ${fd.containingMessage.name}"
-          )
+          ),
+          allowNumericBooleans = config.areNumericBooleanValuesAllowed
         )
     }
 }
@@ -902,7 +909,8 @@ object JsonFormat {
   def parsePrimitive(
       protoType: FieldDescriptorProto.Type,
       value: JValue,
-      onError: => PValue
+      onError: => PValue,
+      allowNumericBooleans: Boolean = false
   ): PValue =
     (protoType, value) match {
       case (Type.TYPE_UINT32 | Type.TYPE_FIXED32, JInt(x)) =>
@@ -966,6 +974,13 @@ object JsonFormat {
       case (Type.TYPE_BOOL, JBool(b))         => PBoolean(b)
       case (Type.TYPE_BOOL, JString("true"))  => PBoolean(true)
       case (Type.TYPE_BOOL, JString("false")) => PBoolean(false)
+      case (Type.TYPE_BOOL, JInt(i)) => {
+        (allowNumericBooleans, i.toInt) match {
+          case (true, 0) => PBoolean(false)
+          case (true, 1) => PBoolean(true)
+          case (_, _) => onError
+        }
+      }
       case (Type.TYPE_STRING, JString(s))     => PString(s)
       case (Type.TYPE_BYTES, JString(s)) =>
         PByteString(
diff --git a/src/test/scala/scalapb/json4s/JsonFormatSpec.scala b/src/test/scala/scalapb/json4s/JsonFormatSpec.scala
index e030fb17..75357800 100644
--- a/src/test/scala/scalapb/json4s/JsonFormatSpec.scala
+++ b/src/test/scala/scalapb/json4s/JsonFormatSpec.scala
@@ -603,6 +603,29 @@ class JsonFormatSpec
     assertRejects("optionalDouble", (minDouble.multiply(moreThanOne).toString))
   }
 
+  "parser" should "parse numeric boolean values when enabled" in {
+    val parser = new Parser().allowNumericBooleanValues
+    def validateRejects(json: String): Assertion = {
+      a[JsonFormatException] mustBe thrownBy {
+        parser.fromJsonString[MyTest](json)
+      }
+    }
+
+    parser.fromJsonString[MyTest]("""{"optBool":1}""") must be(
+      MyTest(optBool = Some(true))
+    )
+    parser.fromJsonString[MyTest]("""{"optBool":0}""") must be(
+      MyTest(optBool = Some(false))
+    )
+
+    // Only 0 and 1 as integers should be parsed
+    validateRejects("""{"optBool":2}""")
+    validateRejects("""{"optBool":-1}""")
+    validateRejects("""{"optBool":"0"}""")
+    validateRejects("""{"optBool":"1"}""")
+  }
+
+
   val anyEnabledJavaTypeRegistry = JavaTypeRegistry
     .newBuilder()
     .add(TestProto.companion.javaDescriptor)