Add failing test

src/test/kotlin/com/cjbooms/fabrikt/generators/ModelGeneratorTest.kt

@@ -56,6 +56,7 @@ class ModelGeneratorTest {
         "discriminatedOneOf",
         "openapi310",
         "binary",
+        "oneOfMarkerInterface",
     )
 
     @BeforeEach

src/test/resources/examples/oneOfMarkerInterface/api.yaml

@@ -0,0 +1,25 @@
+openapi: 3.0.0
+info:
+paths:
+components:
+  schemas:
+
+    State:
+      oneOf:
+        - $ref: '#/components/schemas/StateA'
+        - $ref: '#/components/schemas/StateB'
+
+    StateA:
+      type: object
+      required:
+        - status
+      properties:
+        status:
+          type: string
+    StateB:
+      type: object
+      required:
+        - mode
+      properties:
+        mode:
+          type: string

src/test/resources/examples/oneOfMarkerInterface/models/Models.kt

@@ -0,0 +1,21 @@
+package examples.oneOfMarkerInterface.models
+
+import com.fasterxml.jackson.`annotation`.JsonProperty
+import javax.validation.constraints.NotNull
+import kotlin.String
+
+public sealed interface State
+
+public data class StateA(
+    @param:JsonProperty("status")
+    @get:JsonProperty("status")
+    @get:NotNull
+    public val status: String,
+) : State
+
+public data class StateB(
+    @param:JsonProperty("mode")
+    @get:JsonProperty("mode")
+    @get:NotNull
+    public val mode: String,
+) : State