[KOTLIN-CLIENT] fix Parent interface class having incorrect collection property type List instead of Set (#22850)

Picazsoo · web-flow · commit 95e8360c19b4 · 2026-02-01T15:11:56.000+08:00
* fix issue #22696 * reduce unnecessary repetition in mustache schema * add unit tests & regenerate files * regenerate files
diff --git a/modules/openapi-generator/src/main/resources/kotlin-client/data_class_opt_var.mustache b/modules/openapi-generator/src/main/resources/kotlin-client/data_class_opt_var.mustache
@@ -21,4 +21,4 @@
     {{#deprecated}}
     @Deprecated(message = "This property is deprecated.")
     {{/deprecated}}
-    {{#multiplatform}}@SerialName(value = "{{{vendorExtensions.x-base-name-literal}}}") {{/multiplatform}}{{#isInherited}}override {{/isInherited}}{{>modelMutable}} {{{name}}}: {{#isArray}}{{#isList}}{{#uniqueItems}}kotlin.collections.{{#modelMutable}}Mutable{{/modelMutable}}Set{{/uniqueItems}}{{^uniqueItems}}kotlin.collections.{{#modelMutable}}Mutable{{/modelMutable}}List{{/uniqueItems}}{{/isList}}{{^isList}}kotlin.Array{{/isList}}<{{^items.isEnum}}{{^items.isPrimitiveType}}{{^items.isModel}}{{#kotlinx_serialization}}@Contextual {{/kotlinx_serialization}}{{/items.isModel}}{{/items.isPrimitiveType}}{{{items.dataType}}}{{/items.isEnum}}{{#items.isEnum}}{{classname}}.{{{nameInPascalCase}}}{{/items.isEnum}}>{{/isArray}}{{^isEnum}}{{^isArray}}{{{dataType}}}{{/isArray}}{{/isEnum}}{{#isEnum}}{{^isArray}}{{classname}}.{{{nameInPascalCase}}}{{/isArray}}{{/isEnum}}? = {{^defaultValue}}null{{/defaultValue}}{{#defaultValue}}{{^isNumber}}{{{defaultValue}}}{{/isNumber}}{{#isNumber}}{{^multiplatform}}{{{dataType}}}("{{{defaultValue}}}"){{/multiplatform}}{{#multiplatform}}({{{defaultValue}}}).toDouble(){{/multiplatform}}{{/isNumber}}{{/defaultValue}}
+    {{#multiplatform}}@SerialName(value = "{{{vendorExtensions.x-base-name-literal}}}") {{/multiplatform}}{{#isInherited}}override {{/isInherited}}{{>modelMutable}} {{{name}}}: {{#isArray}}{{#isList}}kotlin.collections.{{#modelMutable}}Mutable{{/modelMutable}}{{#uniqueItems}}Set{{/uniqueItems}}{{^uniqueItems}}List{{/uniqueItems}}{{/isList}}{{^isList}}kotlin.Array{{/isList}}<{{^items.isEnum}}{{^items.isPrimitiveType}}{{^items.isModel}}{{#kotlinx_serialization}}@Contextual {{/kotlinx_serialization}}{{/items.isModel}}{{/items.isPrimitiveType}}{{{items.dataType}}}{{/items.isEnum}}{{#items.isEnum}}{{classname}}.{{{nameInPascalCase}}}{{/items.isEnum}}>{{/isArray}}{{^isEnum}}{{^isArray}}{{{dataType}}}{{/isArray}}{{/isEnum}}{{#isEnum}}{{^isArray}}{{classname}}.{{{nameInPascalCase}}}{{/isArray}}{{/isEnum}}? = {{^defaultValue}}null{{/defaultValue}}{{#defaultValue}}{{^isNumber}}{{{defaultValue}}}{{/isNumber}}{{#isNumber}}{{^multiplatform}}{{{dataType}}}("{{{defaultValue}}}"){{/multiplatform}}{{#multiplatform}}({{{defaultValue}}}).toDouble(){{/multiplatform}}{{/isNumber}}{{/defaultValue}}
diff --git a/modules/openapi-generator/src/main/resources/kotlin-client/data_class_req_var.mustache b/modules/openapi-generator/src/main/resources/kotlin-client/data_class_req_var.mustache
@@ -21,4 +21,4 @@
     {{#deprecated}}
     @Deprecated(message = "This property is deprecated.")
     {{/deprecated}}
-    {{#multiplatform}}@SerialName(value = "{{{vendorExtensions.x-base-name-literal}}}") @Required {{/multiplatform}}{{#isInherited}}override {{/isInherited}}{{>modelMutable}} {{{name}}}: {{#isArray}}{{#isList}}{{#uniqueItems}}kotlin.collections.{{#modelMutable}}Mutable{{/modelMutable}}Set{{/uniqueItems}}{{^uniqueItems}}kotlin.collections.{{#modelMutable}}Mutable{{/modelMutable}}List{{/uniqueItems}}{{/isList}}{{^isList}}kotlin.Array{{/isList}}<{{^items.isEnum}}{{^items.isPrimitiveType}}{{^items.isModel}}{{#kotlinx_serialization}}@Contextual {{/kotlinx_serialization}}{{/items.isModel}}{{/items.isPrimitiveType}}{{{items.dataType}}}{{/items.isEnum}}{{#items.isEnum}}{{classname}}.{{{nameInPascalCase}}}{{/items.isEnum}}>{{/isArray}}{{^isEnum}}{{^isArray}}{{{dataType}}}{{/isArray}}{{/isEnum}}{{#isEnum}}{{^isArray}}{{classname}}.{{{nameInPascalCase}}}{{/isArray}}{{/isEnum}}{{#isNullable}}?{{/isNullable}}{{#defaultValue}} = {{^isNumber}}{{{defaultValue}}}{{/isNumber}}{{#isNumber}}{{^multiplatform}}{{{dataType}}}("{{{defaultValue}}}"){{/multiplatform}}{{#multiplatform}}({{{defaultValue}}}).toDouble(){{/multiplatform}}{{/isNumber}}{{/defaultValue}}
+    {{#multiplatform}}@SerialName(value = "{{{vendorExtensions.x-base-name-literal}}}") @Required {{/multiplatform}}{{#isInherited}}override {{/isInherited}}{{>modelMutable}} {{{name}}}: {{#isArray}}{{#isList}}kotlin.collections.{{#modelMutable}}Mutable{{/modelMutable}}{{#uniqueItems}}Set{{/uniqueItems}}{{^uniqueItems}}List{{/uniqueItems}}{{/isList}}{{^isList}}kotlin.Array{{/isList}}<{{^items.isEnum}}{{^items.isPrimitiveType}}{{^items.isModel}}{{#kotlinx_serialization}}@Contextual {{/kotlinx_serialization}}{{/items.isModel}}{{/items.isPrimitiveType}}{{{items.dataType}}}{{/items.isEnum}}{{#items.isEnum}}{{classname}}.{{{nameInPascalCase}}}{{/items.isEnum}}>{{/isArray}}{{^isEnum}}{{^isArray}}{{{dataType}}}{{/isArray}}{{/isEnum}}{{#isEnum}}{{^isArray}}{{classname}}.{{{nameInPascalCase}}}{{/isArray}}{{/isEnum}}{{#isNullable}}?{{/isNullable}}{{#defaultValue}} = {{^isNumber}}{{{defaultValue}}}{{/isNumber}}{{#isNumber}}{{^multiplatform}}{{{dataType}}}("{{{defaultValue}}}"){{/multiplatform}}{{#multiplatform}}({{{defaultValue}}}).toDouble(){{/multiplatform}}{{/isNumber}}{{/defaultValue}}
diff --git a/modules/openapi-generator/src/main/resources/kotlin-client/interface_opt_var.mustache b/modules/openapi-generator/src/main/resources/kotlin-client/interface_opt_var.mustache
@@ -15,4 +15,4 @@
     {{^isEnum}}{{^isArray}}{{^isPrimitiveType}}{{^isModel}}@Contextual {{/isModel}}{{/isPrimitiveType}}{{/isArray}}{{/isEnum}}@SerialName(value = "{{{vendorExtensions.x-base-name-literal}}}")
     {{/kotlinx_serialization}}
     {{/multiplatform}}
-    {{#multiplatform}}@SerialName(value = "{{{vendorExtensions.x-base-name-literal}}}") abstract {{/multiplatform}}{{#kotlinx_serialization}}abstract {{/kotlinx_serialization}}{{>modelMutable}} {{{name}}}: {{#isArray}}{{#isList}}kotlin.collections.{{#modelMutable}}Mutable{{/modelMutable}}List{{/isList}}{{^isList}}kotlin.Array{{/isList}}<{{^items.isEnum}}{{^items.isPrimitiveType}}{{^items.isModel}}{{#kotlinx_serialization}}@Contextual {{/kotlinx_serialization}}{{/items.isModel}}{{/items.isPrimitiveType}}{{{items.dataType}}}{{/items.isEnum}}{{#items.isEnum}}{{classname}}.{{{nameInPascalCase}}}{{/items.isEnum}}>{{/isArray}}{{^isEnum}}{{^isArray}}{{{dataType}}}{{/isArray}}{{/isEnum}}{{#isEnum}}{{^isArray}}{{classname}}.{{{nameInPascalCase}}}{{/isArray}}{{/isEnum}}?
+    {{#multiplatform}}@SerialName(value = "{{{vendorExtensions.x-base-name-literal}}}") abstract {{/multiplatform}}{{#kotlinx_serialization}}abstract {{/kotlinx_serialization}}{{>modelMutable}} {{{name}}}: {{#isArray}}{{#isList}}kotlin.collections.{{#modelMutable}}Mutable{{/modelMutable}}{{#uniqueItems}}Set{{/uniqueItems}}{{^uniqueItems}}List{{/uniqueItems}}{{/isList}}{{^isList}}kotlin.Array{{/isList}}<{{^items.isEnum}}{{^items.isPrimitiveType}}{{^items.isModel}}{{#kotlinx_serialization}}@Contextual {{/kotlinx_serialization}}{{/items.isModel}}{{/items.isPrimitiveType}}{{{items.dataType}}}{{/items.isEnum}}{{#items.isEnum}}{{classname}}.{{{nameInPascalCase}}}{{/items.isEnum}}>{{/isArray}}{{^isEnum}}{{^isArray}}{{{dataType}}}{{/isArray}}{{/isEnum}}{{#isEnum}}{{^isArray}}{{classname}}.{{{nameInPascalCase}}}{{/isArray}}{{/isEnum}}?
diff --git a/modules/openapi-generator/src/main/resources/kotlin-client/interface_req_var.mustache b/modules/openapi-generator/src/main/resources/kotlin-client/interface_req_var.mustache
@@ -15,4 +15,4 @@
     {{^isEnum}}{{^isArray}}{{^isPrimitiveType}}{{^isModel}}@Contextual {{/isModel}}{{/isPrimitiveType}}{{/isArray}}{{/isEnum}}@SerialName(value = "{{{vendorExtensions.x-base-name-literal}}}")
     {{/kotlinx_serialization}}
     {{/multiplatform}}
-    {{#multiplatform}}@SerialName(value = "{{{vendorExtensions.x-base-name-literal}}}") @Required abstract {{/multiplatform}}{{#kotlinx_serialization}}abstract {{/kotlinx_serialization}}{{>modelMutable}} {{{name}}}: {{#isArray}}{{#isList}}kotlin.collections.{{#modelMutable}}Mutable{{/modelMutable}}List{{/isList}}{{^isList}}kotlin.Array{{/isList}}<{{^items.isEnum}}{{^items.isPrimitiveType}}{{^items.isModel}}{{#kotlinx_serialization}}@Contextual {{/kotlinx_serialization}}{{/items.isModel}}{{/items.isPrimitiveType}}{{{items.dataType}}}{{/items.isEnum}}{{#items.isEnum}}{{classname}}.{{{nameInPascalCase}}}{{/items.isEnum}}>{{/isArray}}{{^isEnum}}{{^isArray}}{{{dataType}}}{{/isArray}}{{/isEnum}}{{#isEnum}}{{^isArray}}{{classname}}.{{{nameInPascalCase}}}{{/isArray}}{{/isEnum}}{{#isNullable}}?{{/isNullable}}
+    {{#multiplatform}}@SerialName(value = "{{{vendorExtensions.x-base-name-literal}}}") @Required abstract {{/multiplatform}}{{#kotlinx_serialization}}abstract {{/kotlinx_serialization}}{{>modelMutable}} {{{name}}}: {{#isArray}}{{#isList}}kotlin.collections.{{#modelMutable}}Mutable{{/modelMutable}}{{#uniqueItems}}Set{{/uniqueItems}}{{^uniqueItems}}List{{/uniqueItems}}{{/isList}}{{^isList}}kotlin.Array{{/isList}}<{{^items.isEnum}}{{^items.isPrimitiveType}}{{^items.isModel}}{{#kotlinx_serialization}}@Contextual {{/kotlinx_serialization}}{{/items.isModel}}{{/items.isPrimitiveType}}{{{items.dataType}}}{{/items.isEnum}}{{#items.isEnum}}{{classname}}.{{{nameInPascalCase}}}{{/items.isEnum}}>{{/isArray}}{{^isEnum}}{{^isArray}}{{{dataType}}}{{/isArray}}{{/isEnum}}{{#isEnum}}{{^isArray}}{{classname}}.{{{nameInPascalCase}}}{{/isArray}}{{/isEnum}}{{#isNullable}}?{{/isNullable}}
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/kotlin/KotlinClientCodegenModelTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/kotlin/KotlinClientCodegenModelTest.java
@@ -649,6 +649,10 @@ public void polymorphicJacksonSerialization() throws IOException {
         // base properties are present
         TestUtils.assertFileContains(animalKt, "val id");
         TestUtils.assertFileContains(animalKt, "val optionalProperty");
+        // base array with unique items = false is correctly handled as List
+        TestUtils.assertFileContains(animalKt, "val stringArray: kotlin.collections.List<kotlin.String>");
+        // base array with unique items = true is correctly handled as Set
+        TestUtils.assertFileContains(animalKt, "val stringSet: kotlin.collections.Set<kotlin.String>");
         // base doesn't contain discriminator
         TestUtils.assertFileNotContains(animalKt, "val discriminator");
 
@@ -658,6 +662,10 @@ public void polymorphicJacksonSerialization() throws IOException {
         // derived properties are overridden
         TestUtils.assertFileContains(birdKt, "override val id");
         TestUtils.assertFileContains(birdKt, "override val optionalProperty");
+        // derived array with unique items = false is correctly handled as List and with override
+        TestUtils.assertFileContains(birdKt, "override val stringArray: kotlin.collections.List<kotlin.String>");
+        // derived array with unique items = true is correctly handled as Set and with override
+        TestUtils.assertFileContains(birdKt, "override val stringSet: kotlin.collections.Set<kotlin.String>");
         // derived doesn't contain disciminator
         TestUtils.assertFileNotContains(birdKt, "val discriminator");
     }
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/kotlin/KotlinSpringServerCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/kotlin/KotlinSpringServerCodegenTest.java
@@ -89,6 +89,8 @@ public void polymorphicJacksonSerialization() throws IOException {
         // base properties are present
         TestUtils.assertFileContains(animalKt, "val id");
         TestUtils.assertFileContains(animalKt, "val optionalProperty");
+        TestUtils.assertFileContains(animalKt, "val stringArray: kotlin.collections.List<kotlin.String>");
+        TestUtils.assertFileContains(animalKt, "val stringSet: kotlin.collections.Set<kotlin.String>");
         // base doesn't contain discriminator
         TestUtils.assertFileNotContains(animalKt, "val discriminator");
 
@@ -98,6 +100,8 @@ public void polymorphicJacksonSerialization() throws IOException {
         // derived properties are overridden
         TestUtils.assertFileContains(birdKt, "override val id");
         TestUtils.assertFileContains(birdKt, "override val optionalProperty");
+        TestUtils.assertFileContains(birdKt, "override val stringArray: kotlin.collections.List<kotlin.String>");
+        TestUtils.assertFileContains(birdKt, "override val stringSet: kotlin.collections.Set<kotlin.String>");
         // derived doesn't contain disciminator
         TestUtils.assertFileNotContains(birdKt, "val discriminator");
     }
diff --git a/modules/openapi-generator/src/test/resources/3_0/kotlin/polymorphism.yaml b/modules/openapi-generator/src/test/resources/3_0/kotlin/polymorphism.yaml
@@ -41,8 +41,19 @@ components:
           format: uuid
         optional_property:
           type: number
+        stringSet:
+          type: array
+          items:
+            type: string
+          uniqueItems: true
+        stringArray:
+          type: array
+          items:
+            type: string
       required:
         - id
+        - string_set
+        - string_array
       discriminator:
         propertyName: discriminator
         mapping:
diff --git a/samples/client/petstore/kotlin-allOf-discriminator-kotlinx-serialization/docs/Animal.md b/samples/client/petstore/kotlin-allOf-discriminator-kotlinx-serialization/docs/Animal.md
@@ -6,6 +6,8 @@
 | ------------ | ------------- | ------------- | ------------- |
 | **id** | [**java.util.UUID**](java.util.UUID.md) |  |  |
 | **optionalProperty** | [**java.math.BigDecimal**](java.math.BigDecimal.md) |  |  [optional] |
+| **stringSet** | **kotlin.collections.Set&lt;kotlin.String&gt;** |  |  [optional] |
+| **stringArray** | **kotlin.collections.List&lt;kotlin.String&gt;** |  |  [optional] |
 
 
 
diff --git a/samples/client/petstore/kotlin-allOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/models/Animal.kt b/samples/client/petstore/kotlin-allOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/models/Animal.kt
@@ -32,6 +32,8 @@ import kotlinx.serialization.json.JsonClassDiscriminator
  *
  * @param id 
  * @param optionalProperty 
+ * @param stringSet 
+ * @param stringArray 
  */
 @Serializable
 
@@ -44,6 +46,10 @@ sealed class Animal {
     abstract val id: java.util.UUID
     @Contextual @SerialName(value = "optional_property")
     abstract val optionalProperty: java.math.BigDecimal?
+    @SerialName(value = "stringSet")
+    abstract val stringSet: kotlin.collections.Set<kotlin.String>?
+    @SerialName(value = "stringArray")
+    abstract val stringArray: kotlin.collections.List<kotlin.String>?
 
 }
 
diff --git a/samples/client/petstore/kotlin-allOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/models/Bird.kt b/samples/client/petstore/kotlin-allOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/models/Bird.kt
@@ -32,6 +32,8 @@ import kotlinx.serialization.encoding.Encoder
  * @param id 
  * @param featherType 
  * @param optionalProperty 
+ * @param stringSet 
+ * @param stringArray 
  */
 @Serializable
 
@@ -45,7 +47,13 @@ data class Bird (
     val featherType: kotlin.String,
 
     @Contextual @SerialName(value = "optional_property")
-    override val optionalProperty: java.math.BigDecimal? = null
+    override val optionalProperty: java.math.BigDecimal? = null,
+
+    @SerialName(value = "stringSet")
+    override val stringSet: kotlin.collections.Set<kotlin.String>? = null,
+
+    @SerialName(value = "stringArray")
+    override val stringArray: kotlin.collections.List<kotlin.String>? = null
 
 ) : Animal() {
 
diff --git a/samples/client/petstore/kotlin-multiplatform-allOf-discriminator/docs/Animal.md b/samples/client/petstore/kotlin-multiplatform-allOf-discriminator/docs/Animal.md
@@ -6,6 +6,8 @@
 | ------------ | ------------- | ------------- | ------------- |
 | **id** | **kotlin.String** |  |  |
 | **optionalProperty** | **kotlin.Double** |  |  [optional] |
+| **stringSet** | **kotlin.collections.Set&lt;kotlin.String&gt;** |  |  [optional] |
+| **stringArray** | **kotlin.collections.List&lt;kotlin.String&gt;** |  |  [optional] |
 
 
 
diff --git a/samples/client/petstore/kotlin-multiplatform-allOf-discriminator/src/commonMain/kotlin/org/openapitools/client/models/Animal.kt b/samples/client/petstore/kotlin-multiplatform-allOf-discriminator/src/commonMain/kotlin/org/openapitools/client/models/Animal.kt
@@ -26,6 +26,8 @@ import kotlinx.serialization.json.JsonClassDiscriminator
  *
  * @param id 
  * @param optionalProperty 
+ * @param stringSet 
+ * @param stringArray 
  */
 @Serializable
 
@@ -36,6 +38,8 @@ sealed class Animal {
 
     @SerialName(value = "id") @Required abstract val id: kotlin.String
     @SerialName(value = "optional_property") abstract val optionalProperty: kotlin.Double?
+    @SerialName(value = "stringSet") abstract val stringSet: kotlin.collections.Set<kotlin.String>?
+    @SerialName(value = "stringArray") abstract val stringArray: kotlin.collections.List<kotlin.String>?
 
 }
 
diff --git a/samples/client/petstore/kotlin-multiplatform-allOf-discriminator/src/commonMain/kotlin/org/openapitools/client/models/Bird.kt b/samples/client/petstore/kotlin-multiplatform-allOf-discriminator/src/commonMain/kotlin/org/openapitools/client/models/Bird.kt
@@ -27,6 +27,8 @@ import kotlinx.serialization.encoding.*
  * @param id 
  * @param featherType 
  * @param optionalProperty 
+ * @param stringSet 
+ * @param stringArray 
  */
 @Serializable
 
@@ -37,7 +39,11 @@ data class Bird (
 
     @SerialName(value = "featherType") @Required val featherType: kotlin.String,
 
-    @SerialName(value = "optional_property") override val optionalProperty: kotlin.Double? = null
+    @SerialName(value = "optional_property") override val optionalProperty: kotlin.Double? = null,
+
+    @SerialName(value = "stringSet") override val stringSet: kotlin.collections.Set<kotlin.String>? = null,
+
+    @SerialName(value = "stringArray") override val stringArray: kotlin.collections.List<kotlin.String>? = null
 
 ) : Animal() {
 
