From 97219a67c0751fe41750babb7d4d18aa68fdcbe1 Mon Sep 17 00:00:00 2001
From: Jeff Lewis <lewisjkl@me.com>
Date: Wed, 18 Oct 2023 14:29:16 -0600
Subject: [PATCH] JSON Schema Optional id Field

---
 .../src/internals/Extractors.scala            | 13 ++++---
 .../src/internals/JsonSchemaToIModel.scala    |  5 ++-
 modules/json-schema/tests/src/RefSpec.scala   | 34 +++++++++++++++++++
 3 files changed, 46 insertions(+), 6 deletions(-)

diff --git a/modules/json-schema/src/internals/Extractors.scala b/modules/json-schema/src/internals/Extractors.scala
index 29cf2d9..44a3c06 100644
--- a/modules/json-schema/src/internals/Extractors.scala
+++ b/modules/json-schema/src/internals/Extractors.scala
@@ -250,7 +250,7 @@ object Extractors {
   /*
    * The most complicated thing
    */
-  abstract class JsonSchemaCaseRefBuilder(id: String, ns: Path)
+  abstract class JsonSchemaCaseRefBuilder(id: Option[String], ns: Path)
       extends smithytranslate.openapi.internals.CaseRefBuilder(ns) {
     def unapply(sch: Schema): Option[Either[ModelError, DefId]] = sch match {
       case ref: ReferenceSchema =>
@@ -260,11 +260,14 @@ object Extractors {
         // The number of `/` chars is not always consistent between the id and the refValue.
         val fileRegex = "^file:\\/*"
         val refValueNoPrefix = refValue.replaceFirst(fileRegex, "")
-        val idNoPrefix = id.replaceFirst(fileRegex, "")
         val sanitisedRefValue =
-          if (refValueNoPrefix.startsWith(idNoPrefix))
-            refValueNoPrefix.drop(idNoPrefix.length())
-          else refValue
+          id.map(_.replaceFirst(fileRegex, ""))
+            .collectFirst {
+              case idNoPrefix if (refValueNoPrefix.startsWith(idNoPrefix)) =>
+                refValueNoPrefix.drop(idNoPrefix.length())
+            }
+            .getOrElse(refValue)
+
         Option(sanitisedRefValue).map(this.apply)
       case _ => None
     }
diff --git a/modules/json-schema/src/internals/JsonSchemaToIModel.scala b/modules/json-schema/src/internals/JsonSchemaToIModel.scala
index 5cb0875..42b4dff 100644
--- a/modules/json-schema/src/internals/JsonSchemaToIModel.scala
+++ b/modules/json-schema/src/internals/JsonSchemaToIModel.scala
@@ -69,7 +69,10 @@ private class JsonSchemaToIModel[F[_]: Parallel: TellShape: TellError](
   implicit val F: Monad[F] = Parallel[F].monad
 
   private val CaseRef =
-    new Extractors.JsonSchemaCaseRefBuilder(jsonSchema.getId(), namespace) {}
+    new Extractors.JsonSchemaCaseRefBuilder(
+      Option(jsonSchema.getId()),
+      namespace
+    ) {}
 
   private val allSchemas: Vector[Local] = {
     val schemaNameSegment =
diff --git a/modules/json-schema/tests/src/RefSpec.scala b/modules/json-schema/tests/src/RefSpec.scala
index 01ecd55..e651404 100644
--- a/modules/json-schema/tests/src/RefSpec.scala
+++ b/modules/json-schema/tests/src/RefSpec.scala
@@ -254,4 +254,38 @@ final class RefSpec extends munit.FunSuite {
 
     TestUtils.runConversionTest(jsonSchString, expectedString)
   }
+
+  test("schema with no id") {
+    val jsonSchString = """|{
+                           |  "$schema": "http://json-schema.org/draft-07/schema#",
+                           |  "title": "Person",
+                           |  "type": "object",
+                           |  "properties": {
+                           |    "firstName": {
+                           |      "$ref": "#/$defs/name"
+                           |    },
+                           |    "lastName": {
+                           |      "$ref": "#/$defs/name"
+                           |    }
+                           |  },
+                           |  "$defs":{
+                           |    "name": {
+                           |      "type": "string"
+                           |    }
+                           |  }
+                           |}
+                           |""".stripMargin
+
+    val expectedString = """|namespace foo
+                            |
+                            |structure Person {
+                            | firstName: Name,
+                            | lastName: Name
+                            |}
+                            |
+                            |string Name
+                            |""".stripMargin
+
+    TestUtils.runConversionTest(jsonSchString, expectedString)
+  }
 }