Lenient numeric decoding (#1606)

* Add a flag to allow for numerics to be decoded from JSON strings
* Expose JSON codec transformations to SimpleRestJsonBuilder
* Add mention in docs how JSON codec transformations are exposed

CHANGELOG.md

@@ -7,6 +7,7 @@ Thank you!
 
 # 0.18.25
 
+* Add A flag to allow for numerics to be decoded from JSON strings (in smithy4s-json).
 * Fixes issues in which applications of some Smithy traits would be incorrectly rendered in Scala code (see [#1602](https://github.com/disneystreaming/smithy4s/pull/1602)).
 * Fixes an issue in which refinements wouldn't work on custom simple shapes (newtypes) (see [#1595](https://github.com/disneystreaming/smithy4s/pull/1595))
 * Fixes a regression from 0.18.4 which incorrectly rendered default values for certain types (see [#1593](https://github.com/disneystreaming/smithy4s/pull/1593))

modules/docs/markdown/03-protocols/04-simple-rest-json/01-overview.md

@@ -90,6 +90,14 @@ See the section about [unions](../../04-codegen/02-unions.md) for a detailed des
 
 By default, optional properties (headers, query parameters, structure fields) that are set to `None` and optional properties that are set to default value will be excluded during encoding process. If you wish to change this so that instead they are included and set to `null` explicitly, you can do so by calling `.withExplicitDefaultsEncoding(true)`.
 
+## Other customisations of JSON codec behaviour
+
+The underlying JSON codecs can be configured with a number of options to cater to niche usecases, via the `.transformJsonCodecs` method, which takes a function that takes in and returns a
+`JsonPayloadCodecCompiler`. For instance, by default, the `NaN` and `Infinity` values are not considered valid during parsing `Float` or `Double` values. This can be amended via
+`.transformJsonCodecs(_.configureJsoniterCodecCompiler(_.withInfinitySupport(true)))`.
+
+The customisations are bound to evolve as we uncover new niche cases that warrant adding new pieces of opt-in behaviour. The default behaviour is kept rather strict as it helps keep competitive performance and safety.
+
 ## Supported traits
 
 Here is the list of traits supported by `SimpleRestJson`

modules/http4s/src/smithy4s/http4s/SimpleRestJsonBuilder.scala

@@ -17,47 +17,67 @@
 package smithy4s
 package http4s
 
-object SimpleRestJsonBuilder extends SimpleRestJsonBuilder(1024, false, true)
+import smithy4s.json.Json
+import smithy4s.json.JsonPayloadCodecCompiler
+
+object SimpleRestJsonBuilder
+    extends SimpleRestJsonBuilder(
+      new internals.SimpleRestJsonCodecs(
+        jsonCodecs = Json.payloadCodecs,
+        explicitDefaultsEncoding = false,
+        hostPrefixInjection = true
+      )
+    )
 
 class SimpleRestJsonBuilder private (
     simpleRestJsonCodecs: internals.SimpleRestJsonCodecs
 ) extends SimpleProtocolBuilder[alloy.SimpleRestJson](
       simpleRestJsonCodecs
     ) {
 
+  @deprecated(message = "Use .withXXX methods instead", since = "0.18.25")
   def this(
       maxArity: Int,
       explicitDefaultsEncoding: Boolean,
       hostPrefixInjection: Boolean
   ) =
     this(
       new internals.SimpleRestJsonCodecs(
-        maxArity,
+        Json.payloadCodecs
+          .withJsoniterCodecCompiler(
+            Json.jsoniter
+              .withMaxArity(maxArity)
+              .withExplicitDefaultsEncoding(explicitDefaultsEncoding)
+          ),
         explicitDefaultsEncoding,
         hostPrefixInjection
       )
     )
 
   def withMaxArity(maxArity: Int): SimpleRestJsonBuilder =
     new SimpleRestJsonBuilder(
-      maxArity,
-      simpleRestJsonCodecs.explicitDefaultsEncoding,
-      simpleRestJsonCodecs.hostPrefixInjection
+      simpleRestJsonCodecs.transformJsonCodecs(
+        _.configureJsoniterCodecCompiler(_.withMaxArity(maxArity))
+      )
     )
 
   def withExplicitDefaultsEncoding(
       explicitDefaultsEncoding: Boolean
   ): SimpleRestJsonBuilder =
     new SimpleRestJsonBuilder(
-      simpleRestJsonCodecs.maxArity,
-      explicitDefaultsEncoding,
-      simpleRestJsonCodecs.hostPrefixInjection
+      simpleRestJsonCodecs.withExplicitDefaultEncoding(explicitDefaultsEncoding)
     )
 
   def disableHostPrefixInjection(): SimpleRestJsonBuilder =
     new SimpleRestJsonBuilder(
-      simpleRestJsonCodecs.maxArity,
-      simpleRestJsonCodecs.explicitDefaultsEncoding,
-      false
+      simpleRestJsonCodecs.withHostPrefixInjection(false)
     )
+
+  /**
+    * Transforms the underlying JSON codec compiler to change its behaviour.
+    */
+  def transformJsonCodecs(
+      f: JsonPayloadCodecCompiler => JsonPayloadCodecCompiler
+  ): SimpleRestJsonBuilder =
+    new SimpleRestJsonBuilder(simpleRestJsonCodecs.transformJsonCodecs(f))
 }

modules/http4s/src/smithy4s/http4s/internals/SimpleRestJsonCodecs.scala

@@ -24,38 +24,43 @@ import smithy4s.http.HttpDiscriminator
 import smithy4s.http.Metadata
 import smithy4s.http._
 import smithy4s.http4s.kernel._
-import smithy4s.json.Json
 import smithy4s.client._
 import smithy4s.codecs.BlobEncoder
 import cats.syntax.all._
 import org.http4s.Response
 import org.http4s.Request
 import org.http4s.Uri
 import smithy4s.http.HttpMethod
+import smithy4s.json.JsonPayloadCodecCompiler
 
 // scalafmt: {maxColumn = 120}
 private[http4s] class SimpleRestJsonCodecs(
-    val maxArity: Int,
+    val jsonCodecs: JsonPayloadCodecCompiler,
     val explicitDefaultsEncoding: Boolean,
     val hostPrefixInjection: Boolean
 ) extends SimpleProtocolCodecs {
   private val hintMask =
     alloy.SimpleRestJson.protocol.hintMask
 
-  private val jsonCodecs = Json.payloadCodecs
-    .withJsoniterCodecCompiler(
-      Json.jsoniter
-        .withHintMask(hintMask)
-        .withMaxArity(maxArity)
-        .withExplicitDefaultsEncoding(explicitDefaultsEncoding)
+  def transformJsonCodecs(f: JsonPayloadCodecCompiler => JsonPayloadCodecCompiler): SimpleRestJsonCodecs =
+    new SimpleRestJsonCodecs(f(jsonCodecs), explicitDefaultsEncoding, hostPrefixInjection)
+
+  def withExplicitDefaultEncoding(newExplicitDefaultsEncoding: Boolean): SimpleRestJsonCodecs =
+    new SimpleRestJsonCodecs(
+      jsonCodecs.configureJsoniterCodecCompiler(_.withExplicitDefaultsEncoding(newExplicitDefaultsEncoding)),
+      newExplicitDefaultsEncoding,
+      hostPrefixInjection
     )
 
+  def withHostPrefixInjection(newHostPrefixInjection: Boolean): SimpleRestJsonCodecs =
+    new SimpleRestJsonCodecs(jsonCodecs, explicitDefaultsEncoding, newHostPrefixInjection)
+
   // val mediaType = HttpMediaType("application/json")
   private val payloadEncoders: BlobEncoder.Compiler =
-    jsonCodecs.encoders
+    jsonCodecs.configureJsoniterCodecCompiler(_.withHintMask(hintMask)).encoders
 
   private val payloadDecoders =
-    jsonCodecs.decoders
+    jsonCodecs.configureJsoniterCodecCompiler(_.withHintMask(hintMask)).decoders
 
   // Adding X-Amzn-Errortype as well to facilitate interop with Amazon-issued code-generators.
   private val errorHeaders = List(

modules/json/src/smithy4s/json/JsoniterCodecCompiler.scala

@@ -78,6 +78,12 @@ trait JsoniterCodecCompiler extends CachedSchemaCompiler[JsonCodec] {
     */
   def withLenientTaggedUnionDecoding: JsoniterCodecCompiler
 
+  /**
+    * Enables lenient decoding of numeric values, where numbers may be carried by JSON strings
+    * as well as JSON numbers.
+    */
+  def withLenientNumericDecoding: JsoniterCodecCompiler
+
 }
 
 object JsoniterCodecCompiler {

modules/json/src/smithy4s/json/internals/JsoniterCodecCompilerImpl.scala

@@ -27,7 +27,8 @@ private[smithy4s] case class JsoniterCodecCompilerImpl(
     infinitySupport: Boolean,
     preserveMapOrder: Boolean,
     hintMask: Option[HintMask],
-    lenientTaggedUnionDecoding: Boolean
+    lenientTaggedUnionDecoding: Boolean,
+    lenientNumericDecoding: Boolean
 ) extends CachedSchemaCompiler.Impl[JCodec]
     with JsoniterCodecCompiler {
 
@@ -59,6 +60,9 @@ private[smithy4s] case class JsoniterCodecCompilerImpl(
   def withLenientTaggedUnionDecoding: JsoniterCodecCompiler =
     copy(lenientTaggedUnionDecoding = true)
 
+  def withLenientNumericDecoding: JsoniterCodecCompiler =
+    copy(lenientNumericDecoding = true)
+
   def fromSchema[A](schema: Schema[A], cache: Cache): JCodec[A] = {
     val visitor = new SchemaVisitorJCodec(
       maxArity,
@@ -67,6 +71,7 @@ private[smithy4s] case class JsoniterCodecCompilerImpl(
       flexibleCollectionsSupport,
       preserveMapOrder,
       lenientTaggedUnionDecoding,
+      lenientNumericDecoding,
       cache
     )
     val amendedSchema =
@@ -88,6 +93,7 @@ private[smithy4s] object JsoniterCodecCompilerImpl {
       flexibleCollectionsSupport = false,
       preserveMapOrder = false,
       lenientTaggedUnionDecoding = false,
+      lenientNumericDecoding = false,
       hintMask = Some(JsoniterCodecCompiler.defaultHintMask)
     )