kotlin-spring: fix exception thrown in enum.forValue (OpenAPITools#21622)

* kotlin-spring: fix exception thrown in enum.forValue

* update samples

Author: swurzinger

modules/openapi-generator/src/main/resources/kotlin-spring/dataClass.mustache

@@ -39,7 +39,8 @@
             @JvmStatic
             @JsonCreator
             fun forValue(value: {{#isContainer}}{{#items}}{{{dataType}}}{{/items}}{{/isContainer}}{{^isContainer}}{{{dataType}}}{{/isContainer}}): {{{nameInPascalCase}}} {
-                return values().first{it -> it.value == value}
+                return values().firstOrNull{it -> it.value == value}
+                    ?: throw IllegalArgumentException("Unexpected value '$value' for enum '{{classname}}'")
             }
         }
     }

modules/openapi-generator/src/main/resources/kotlin-spring/enumClass.mustache

@@ -10,7 +10,8 @@ enum class {{classname}}(@get:JsonValue val value: {{dataType}}) {
         @JvmStatic
         @JsonCreator
         fun forValue(value: {{dataType}}): {{classname}} {
-                return values().first{it -> it.value == value}
+                return values().firstOrNull{it -> it.value == value}
+                    ?: throw IllegalArgumentException("Unexpected value '$value' for enum '{{classname}}'")
         }
     }
 }

samples/server/petstore/kotlin-spring-cloud/src/main/kotlin/org/openapitools/model/Order.kt

@@ -53,7 +53,8 @@ data class Order(
             @JvmStatic
             @JsonCreator
             fun forValue(value: kotlin.String): Status {
-                return values().first{it -> it.value == value}
+                return values().firstOrNull{it -> it.value == value}
+                    ?: throw IllegalArgumentException("Unexpected value '$value' for enum 'Order'")
             }
         }
     }

samples/server/petstore/kotlin-spring-cloud/src/main/kotlin/org/openapitools/model/Pet.kt

@@ -58,7 +58,8 @@ data class Pet(
             @JvmStatic
             @JsonCreator
             fun forValue(value: kotlin.String): Status {
-                return values().first{it -> it.value == value}
+                return values().firstOrNull{it -> it.value == value}
+                    ?: throw IllegalArgumentException("Unexpected value '$value' for enum 'Pet'")
             }
         }
     }

samples/server/petstore/kotlin-spring-default/src/main/kotlin/org/openapitools/model/AnyOfUserOrPet.kt

@@ -94,7 +94,8 @@ data class AnyOfUserOrPet(
             @JvmStatic
             @JsonCreator
             fun forValue(value: kotlin.String): Status {
-                return values().first{it -> it.value == value}
+                return values().firstOrNull{it -> it.value == value}
+                    ?: throw IllegalArgumentException("Unexpected value '$value' for enum 'AnyOfUserOrPet'")
             }
         }
     }

samples/server/petstore/kotlin-spring-default/src/main/kotlin/org/openapitools/model/AnyOfUserOrPetOrArrayString.kt

@@ -94,7 +94,8 @@ data class AnyOfUserOrPetOrArrayString(
             @JvmStatic
             @JsonCreator
             fun forValue(value: kotlin.String): Status {
-                return values().first{it -> it.value == value}
+                return values().firstOrNull{it -> it.value == value}
+                    ?: throw IllegalArgumentException("Unexpected value '$value' for enum 'AnyOfUserOrPetOrArrayString'")
             }
         }
     }

samples/server/petstore/kotlin-spring-default/src/main/kotlin/org/openapitools/model/Order.kt

@@ -59,7 +59,8 @@ data class Order(
             @JvmStatic
             @JsonCreator
             fun forValue(value: kotlin.String): Status {
-                return values().first{it -> it.value == value}
+                return values().firstOrNull{it -> it.value == value}
+                    ?: throw IllegalArgumentException("Unexpected value '$value' for enum 'Order'")
             }
         }
     }

samples/server/petstore/kotlin-spring-default/src/main/kotlin/org/openapitools/model/Pet.kt

@@ -64,7 +64,8 @@ data class Pet(
             @JvmStatic
             @JsonCreator
             fun forValue(value: kotlin.String): Status {
-                return values().first{it -> it.value == value}
+                return values().firstOrNull{it -> it.value == value}
+                    ?: throw IllegalArgumentException("Unexpected value '$value' for enum 'Pet'")
             }
         }
     }

samples/server/petstore/kotlin-spring-default/src/main/kotlin/org/openapitools/model/UserOrPet.kt

@@ -94,7 +94,8 @@ data class UserOrPet(
             @JvmStatic
             @JsonCreator
             fun forValue(value: kotlin.String): Status {
-                return values().first{it -> it.value == value}
+                return values().firstOrNull{it -> it.value == value}
+                    ?: throw IllegalArgumentException("Unexpected value '$value' for enum 'UserOrPet'")
             }
         }
     }

samples/server/petstore/kotlin-spring-default/src/main/kotlin/org/openapitools/model/UserOrPetOrArrayString.kt

@@ -94,7 +94,8 @@ data class UserOrPetOrArrayString(
             @JvmStatic
             @JsonCreator
             fun forValue(value: kotlin.String): Status {
-                return values().first{it -> it.value == value}
+                return values().firstOrNull{it -> it.value == value}
+                    ?: throw IllegalArgumentException("Unexpected value '$value' for enum 'UserOrPetOrArrayString'")
             }
         }
     }