[KOTLIN-SPRING/KOTLIN-CLIENT] BUG - fix json deserialization when kotlin attribute name differs from json attribute name

modules/openapi-generator/src/main/resources/kotlin-client/data_class_opt_var.mustache

@@ -9,6 +9,7 @@
     @SerializedName("{{{vendorExtensions.x-base-name-literal}}}")
     {{/gson}}
     {{#jackson}}
+    @param:JsonProperty("{{{vendorExtensions.x-base-name-literal}}}")
     @get:JsonProperty("{{{vendorExtensions.x-base-name-literal}}}")
     {{/jackson}}
     {{#kotlinx_serialization}}

modules/openapi-generator/src/main/resources/kotlin-client/data_class_req_var.mustache

@@ -9,6 +9,7 @@
     @SerializedName("{{{vendorExtensions.x-base-name-literal}}}")
     {{/gson}}
     {{#jackson}}
+    @param:JsonProperty("{{{vendorExtensions.x-base-name-literal}}}")
     @get:JsonProperty("{{{vendorExtensions.x-base-name-literal}}}")
     {{/jackson}}
     {{#kotlinx_serialization}}

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

@@ -6,4 +6,5 @@
     @field:JsonInclude(JsonInclude.Include.NON_NULL){{/isNullable}}{{#vendorExtensions.x-has-json-setter-nulls-skip}}
     @field:JsonSetter(nulls = Nulls.SKIP){{/vendorExtensions.x-has-json-setter-nulls-skip}}{{#vendorExtensions.x-has-json-setter-nulls-fail}}
     @field:JsonSetter(nulls = Nulls.FAIL){{/vendorExtensions.x-has-json-setter-nulls-fail}}
+    @param:JsonProperty("{{{baseName}}}")
     @get:JsonProperty("{{{baseName}}}"){{#isInherited}} override{{/isInherited}} {{>modelMutable}} {{{name}}}: {{#vendorExtensions.x-is-jackson-optional-nullable}}JsonNullable<{{#isEnum}}{{#isArray}}{{baseType}}<{{/isArray}}{{classname}}.{{{nameInPascalCase}}}{{#isArray}}>{{/isArray}}{{/isEnum}}{{^isEnum}}{{{dataType}}}{{/isEnum}}>{{/vendorExtensions.x-is-jackson-optional-nullable}}{{^vendorExtensions.x-is-jackson-optional-nullable}}{{#isEnum}}{{#isArray}}{{baseType}}<{{/isArray}}{{classname}}.{{{nameInPascalCase}}}{{#isArray}}>{{/isArray}}{{/isEnum}}{{^isEnum}}{{{dataType}}}{{/isEnum}}?{{/vendorExtensions.x-is-jackson-optional-nullable}} = {{#vendorExtensions.x-is-jackson-optional-nullable}}JsonNullable.undefined(){{/vendorExtensions.x-is-jackson-optional-nullable}}{{^vendorExtensions.x-is-jackson-optional-nullable}}{{^defaultValue}}null{{/defaultValue}}{{#defaultValue}}{{^isNumber}}{{{defaultValue}}}{{/isNumber}}{{#isNumber}}{{{dataType}}}("{{{defaultValue}}}"){{/isNumber}}{{/defaultValue}}{{/vendorExtensions.x-is-jackson-optional-nullable}}

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

@@ -2,4 +2,5 @@
     @Schema({{#example}}example = "{{#lambdaRemoveLineBreak}}{{#lambdaEscapeInNormalString}}{{{.}}}{{/lambdaEscapeInNormalString}}{{/lambdaRemoveLineBreak}}", {{/example}}required = true, {{#isReadOnly}}readOnly = {{{isReadOnly}}}, {{/isReadOnly}}description = "{{{description}}}"){{/swagger2AnnotationLibrary}}{{#swagger1AnnotationLibrary}}
     @ApiModelProperty({{#example}}example = "{{#lambdaRemoveLineBreak}}{{#lambdaEscapeInNormalString}}{{{.}}}{{/lambdaEscapeInNormalString}}{{/lambdaRemoveLineBreak}}", {{/example}}required = true, {{#isReadOnly}}readOnly = {{{isReadOnly}}}, {{/isReadOnly}}value = "{{{description}}}"){{/swagger1AnnotationLibrary}}{{#vendorExtensions.x-field-extra-annotation}}
     {{{.}}}{{/vendorExtensions.x-field-extra-annotation}}
+    @param:JsonProperty("{{{baseName}}}")
     @get:JsonProperty("{{{baseName}}}", required = true){{#isInherited}} override{{/isInherited}} {{>modelMutable}} {{{name}}}: {{#isEnum}}{{#isArray}}{{baseType}}<{{/isArray}}{{classname}}.{{{nameInPascalCase}}}{{#isArray}}>{{/isArray}}{{/isEnum}}{{^isEnum}}{{{dataType}}}{{/isEnum}}{{#isNullable}}?{{/isNullable}}{{#defaultValue}} = {{^isNumber}}{{{defaultValue}}}{{/isNumber}}{{#isNumber}}{{{dataType}}}("{{{defaultValue}}}"){{/isNumber}}{{/defaultValue}}

modules/openapi-generator/src/test/java/org/openapitools/codegen/kotlin/KotlinClientCodegenModelTest.java

@@ -1037,6 +1037,53 @@ public void testCompanionObjectGeneratesCompanionInModel() throws IOException {
         TestUtils.assertFileContains(petModel, "companion object { }");
     }
 
+    @Test(description = "nameMappings: @param:JsonProperty must use the original JSON field name for deserialization")
+    public void paramJsonPropertyAnnotationWithNameMappings() throws IOException {
+        // When a property is renamed via nameMappings, @param:JsonProperty must carry the
+        // original JSON field name so Jackson can deserialize from the correct JSON key.
+        File output = Files.createTempDirectory("test").toFile();
+        output.deleteOnExit();
+
+        final CodegenConfigurator configurator = new CodegenConfigurator()
+                .setGeneratorName("kotlin")
+                .setInputSpec("src/test/resources/3_0/kotlin/param-json-property.yaml")
+                .setOutputDir(output.getAbsolutePath().replace("\\", "/"))
+                .addAdditionalProperty(CodegenConstants.SERIALIZATION_LIBRARY, "jackson")
+                .addNameMapping("snake_case_value", "mappedValue");
+
+        DefaultGenerator generator = new DefaultGenerator();
+        generator.opts(configurator.toClientOptInput()).generate();
+
+        Path itemModel = Paths.get(output.getAbsolutePath() + "/src/main/kotlin/org/openapitools/client/models/Item.kt");
+        // @param:JsonProperty must reference the original JSON key, not the mapped Kotlin name
+        TestUtils.assertFileContains(itemModel,
+                "@param:JsonProperty(\"snake_case_value\")\n    @get:JsonProperty(\"snake_case_value\")\n    val mappedValue");
+    }
+
+    @Test(description = "auto-renamed digit-starting property: @param:JsonProperty must use the original JSON field name")
+    public void paramJsonPropertyAnnotationWithDigitStartingPropertyName() throws IOException {
+        // When a property name starts with a digit, the Kotlin codegen wraps it in backticks
+        // (e.g. "2nd_field" -> `2ndField`). @param:JsonProperty must still carry the original
+        // JSON field name so that Jackson can deserialize it correctly.
+        File output = Files.createTempDirectory("test").toFile();
+        output.deleteOnExit();
+
+        final CodegenConfigurator configurator = new CodegenConfigurator()
+                .setGeneratorName("kotlin")
+                .setInputSpec("src/test/resources/3_0/kotlin/param-json-property.yaml")
+                .setOutputDir(output.getAbsolutePath().replace("\\", "/"))
+                .addAdditionalProperty(CodegenConstants.SERIALIZATION_LIBRARY, "jackson");
+
+        DefaultGenerator generator = new DefaultGenerator();
+        generator.opts(configurator.toClientOptInput()).generate();
+
+        Path itemModel = Paths.get(output.getAbsolutePath() + "/src/main/kotlin/org/openapitools/client/models/Item.kt");
+        // @param:JsonProperty must reference the original JSON key even when the property
+        // is auto-renamed to a backtick-escaped identifier
+        TestUtils.assertFileContains(itemModel,
+                "@param:JsonProperty(\"2nd_field\")\n    @get:JsonProperty(\"2nd_field\")\n    val `2ndField`");
+    }
+
     private static class ModelNameTest {
         private final String expectedName;
         private final String expectedClassName;

modules/openapi-generator/src/test/java/org/openapitools/codegen/kotlin/spring/KotlinSpringServerCodegenTest.java

@@ -6476,7 +6476,7 @@ public void requiredNullable_scenario3_optionalNonNullable_withDefault() throws
         String content = Files.readString(modelFile);
         int idx = content.indexOf("val optionalNonNullableWithDefault:");
         Assert.assertTrue(idx >= 0, "optionalNonNullableWithDefault property must exist");
-        String context = content.substring(Math.max(0, idx - 200), idx);
+        String context = content.substring(Math.max(0, idx - 300), idx);
         Assert.assertTrue(context.contains("@field:JsonInclude(JsonInclude.Include.NON_NULL)"),
                 "optionalNonNullableWithDefault must have @JsonInclude(NON_NULL)");
         Assert.assertTrue(context.contains("@field:JsonSetter(nulls = Nulls.SKIP)"),
@@ -6777,4 +6777,40 @@ public void schemaMappingWithNullableAllOfRendersNullableKotlinProperty() throws
         String content = Files.readString(myObjectFile.toPath());
         assertThat(content).contains("com.example.ExternalModel?");
     }
+
+    @Test(description = "nameMappings: @param:JsonProperty must use the original JSON field name for deserialization")
+    public void paramJsonPropertyAnnotationWithNameMappings() throws IOException {
+        // When a property is renamed via nameMappings, @param:JsonProperty must carry the
+        // original JSON field name so Jackson can deserialize from the correct JSON key.
+        Map<String, File> files = generateFromContract(
+                "src/test/resources/3_0/kotlin/param-json-property.yaml",
+                new HashMap<>(),
+                new HashMap<>(),
+                configurator -> configurator.addNameMapping("snake_case_value", "mappedValue")
+        );
+
+        File itemFile = files.get("Item.kt");
+        assertThat(itemFile).isNotNull();
+        assertFileContains(
+                itemFile.toPath(),
+                "@param:JsonProperty(\"snake_case_value\")\n    @get:JsonProperty(\"snake_case_value\", required = true) val mappedValue"
+        );
+    }
+
+    @Test(description = "auto-renamed digit-starting property: @param:JsonProperty must use the original JSON field name")
+    public void paramJsonPropertyAnnotationWithDigitStartingPropertyName() throws IOException {
+        // When a property name starts with a digit, the Kotlin codegen wraps it in backticks
+        // (e.g. "2nd_field" -> `2ndField`). @param:JsonProperty must still carry the original
+        // JSON field name so that Jackson can deserialize it correctly.
+        Map<String, File> files = generateFromContract(
+                "src/test/resources/3_0/kotlin/param-json-property.yaml"
+        );
+
+        File itemFile = files.get("Item.kt");
+        assertThat(itemFile).isNotNull();
+        assertFileContains(
+                itemFile.toPath(),
+                "@param:JsonProperty(\"2nd_field\")\n    @get:JsonProperty(\"2nd_field\") val `2ndField`"
+        );
+    }
 }

modules/openapi-generator/src/test/resources/3_0/kotlin/param-json-property.yaml

@@ -0,0 +1,28 @@
+openapi: "3.0.0"
+info:
+  title: Test API for @param:JsonProperty annotation
+  version: "1.0.0"
+paths:
+  /items:
+    get:
+      operationId: listItems
+      responses:
+        "200":
+          description: Success
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Item"
+components:
+  schemas:
+    Item:
+      type: object
+      required:
+        - snake_case_value
+      properties:
+        snake_case_value:
+          type: string
+          description: A required property to be renamed via nameMappings
+        2nd_field:
+          type: string
+          description: An optional property whose name starts with a digit and is auto-renamed

samples/client/echo_api/kotlin-jvm-spring-3-restclient/src/main/kotlin/org/openapitools/client/models/Bird.kt

@@ -37,9 +37,11 @@ import com.fasterxml.jackson.annotation.JsonProperty
 
 data class Bird (
 
+    @param:JsonProperty("size")
     @get:JsonProperty("size")
     val propertySize: kotlin.String? = null,
 
+    @param:JsonProperty("color")
     @get:JsonProperty("color")
     val color: kotlin.String? = null
 

samples/client/echo_api/kotlin-jvm-spring-3-restclient/src/main/kotlin/org/openapitools/client/models/Category.kt

@@ -37,9 +37,11 @@ import com.fasterxml.jackson.annotation.JsonProperty
 
 data class Category (
 
+    @param:JsonProperty("id")
     @get:JsonProperty("id")
     val id: kotlin.Long? = null,
 
+    @param:JsonProperty("name")
     @get:JsonProperty("name")
     val name: kotlin.String? = null
 

samples/client/echo_api/kotlin-jvm-spring-3-restclient/src/main/kotlin/org/openapitools/client/models/DefaultValue.kt

@@ -44,27 +44,35 @@ import com.fasterxml.jackson.annotation.JsonProperty
 
 data class DefaultValue (
 
+    @param:JsonProperty("array_string_enum_ref_default")
     @get:JsonProperty("array_string_enum_ref_default")
     val arrayStringEnumRefDefault: kotlin.collections.List<StringEnumRef>? = null,
 
+    @param:JsonProperty("array_string_enum_default")
     @get:JsonProperty("array_string_enum_default")
     val arrayStringEnumDefault: kotlin.collections.List<DefaultValue.ArrayStringEnumDefault>? = null,
 
+    @param:JsonProperty("array_string_default")
     @get:JsonProperty("array_string_default")
     val arrayStringDefault: kotlin.collections.List<kotlin.String>? = arrayListOf("failure","skipped"),
 
+    @param:JsonProperty("array_integer_default")
     @get:JsonProperty("array_integer_default")
     val arrayIntegerDefault: kotlin.collections.List<kotlin.Int>? = arrayListOf(1,3),
 
+    @param:JsonProperty("array_string")
     @get:JsonProperty("array_string")
     val arrayString: kotlin.collections.List<kotlin.String>? = null,
 
+    @param:JsonProperty("array_string_nullable")
     @get:JsonProperty("array_string_nullable")
     val arrayStringNullable: kotlin.collections.List<kotlin.String>? = null,
 
+    @param:JsonProperty("array_string_extension_nullable")
     @get:JsonProperty("array_string_extension_nullable")
     val arrayStringExtensionNullable: kotlin.collections.List<kotlin.String>? = null,
 
+    @param:JsonProperty("string_nullable")
     @get:JsonProperty("string_nullable")
     val stringNullable: kotlin.String? = null
 

samples/client/echo_api/kotlin-jvm-spring-3-restclient/src/main/kotlin/org/openapitools/client/models/NumberPropertiesOnly.kt

@@ -38,12 +38,15 @@ import com.fasterxml.jackson.annotation.JsonProperty
 
 data class NumberPropertiesOnly (
 
+    @param:JsonProperty("number")
     @get:JsonProperty("number")
     val number: java.math.BigDecimal? = null,
 
+    @param:JsonProperty("float")
     @get:JsonProperty("float")
     val float: kotlin.Float? = null,
 
+    @param:JsonProperty("double")
     @get:JsonProperty("double")
     val double: kotlin.Double? = null
 

samples/client/echo_api/kotlin-jvm-spring-3-restclient/src/main/kotlin/org/openapitools/client/models/Pet.kt

@@ -43,22 +43,28 @@ import com.fasterxml.jackson.annotation.JsonProperty
 
 data class Pet (
 
+    @param:JsonProperty("name")
     @get:JsonProperty("name")
     val name: kotlin.String,
 
+    @param:JsonProperty("photoUrls")
     @get:JsonProperty("photoUrls")
     val photoUrls: kotlin.collections.List<kotlin.String>,
 
+    @param:JsonProperty("id")
     @get:JsonProperty("id")
     val id: kotlin.Long? = null,
 
+    @param:JsonProperty("category")
     @get:JsonProperty("category")
     val category: Category? = null,
 
+    @param:JsonProperty("tags")
     @get:JsonProperty("tags")
     val tags: kotlin.collections.List<Tag>? = null,
 
     /* pet status in the store */
+    @param:JsonProperty("status")
     @get:JsonProperty("status")
     val status: Pet.Status? = null
 

samples/client/echo_api/kotlin-jvm-spring-3-restclient/src/main/kotlin/org/openapitools/client/models/Query.kt

@@ -38,9 +38,11 @@ import com.fasterxml.jackson.annotation.JsonProperty
 data class Query (
 
     /* Query */
+    @param:JsonProperty("id")
     @get:JsonProperty("id")
     val id: kotlin.Long? = null,
 
+    @param:JsonProperty("outcomes")
     @get:JsonProperty("outcomes")
     val outcomes: kotlin.collections.List<Query.Outcomes>? = null
 

samples/client/echo_api/kotlin-jvm-spring-3-restclient/src/main/kotlin/org/openapitools/client/models/Tag.kt

@@ -37,9 +37,11 @@ import com.fasterxml.jackson.annotation.JsonProperty
 
 data class Tag (
 
+    @param:JsonProperty("id")
     @get:JsonProperty("id")
     val id: kotlin.Long? = null,
 
+    @param:JsonProperty("name")
     @get:JsonProperty("name")
     val name: kotlin.String? = null
 

samples/client/echo_api/kotlin-jvm-spring-3-restclient/src/main/kotlin/org/openapitools/client/models/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.kt

@@ -36,6 +36,7 @@ import com.fasterxml.jackson.annotation.JsonProperty
 
 data class TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter (
 
+    @param:JsonProperty("values")
     @get:JsonProperty("values")
     val propertyValues: kotlin.collections.List<kotlin.String>? = null
 

samples/client/echo_api/kotlin-jvm-spring-3-webclient/src/main/kotlin/org/openapitools/client/models/Bird.kt

@@ -37,9 +37,11 @@ import com.fasterxml.jackson.annotation.JsonProperty
 
 data class Bird (
 
+    @param:JsonProperty("size")
     @get:JsonProperty("size")
     val propertySize: kotlin.String? = null,
 
+    @param:JsonProperty("color")
     @get:JsonProperty("color")
     val color: kotlin.String? = null
 

samples/client/echo_api/kotlin-jvm-spring-3-webclient/src/main/kotlin/org/openapitools/client/models/Category.kt

@@ -37,9 +37,11 @@ import com.fasterxml.jackson.annotation.JsonProperty
 
 data class Category (
 
+    @param:JsonProperty("id")
     @get:JsonProperty("id")
     val id: kotlin.Long? = null,
 
+    @param:JsonProperty("name")
     @get:JsonProperty("name")
     val name: kotlin.String? = null
 

samples/client/echo_api/kotlin-jvm-spring-3-webclient/src/main/kotlin/org/openapitools/client/models/DefaultValue.kt

@@ -44,27 +44,35 @@ import com.fasterxml.jackson.annotation.JsonProperty
 
 data class DefaultValue (
 
+    @param:JsonProperty("array_string_enum_ref_default")
     @get:JsonProperty("array_string_enum_ref_default")
     val arrayStringEnumRefDefault: kotlin.collections.List<StringEnumRef>? = null,
 
+    @param:JsonProperty("array_string_enum_default")
     @get:JsonProperty("array_string_enum_default")
     val arrayStringEnumDefault: kotlin.collections.List<DefaultValue.ArrayStringEnumDefault>? = null,
 
+    @param:JsonProperty("array_string_default")
     @get:JsonProperty("array_string_default")
     val arrayStringDefault: kotlin.collections.List<kotlin.String>? = arrayListOf("failure","skipped"),
 
+    @param:JsonProperty("array_integer_default")
     @get:JsonProperty("array_integer_default")
     val arrayIntegerDefault: kotlin.collections.List<kotlin.Int>? = arrayListOf(1,3),
 
+    @param:JsonProperty("array_string")
     @get:JsonProperty("array_string")
     val arrayString: kotlin.collections.List<kotlin.String>? = null,
 
+    @param:JsonProperty("array_string_nullable")
     @get:JsonProperty("array_string_nullable")
     val arrayStringNullable: kotlin.collections.List<kotlin.String>? = null,
 
+    @param:JsonProperty("array_string_extension_nullable")
     @get:JsonProperty("array_string_extension_nullable")
     val arrayStringExtensionNullable: kotlin.collections.List<kotlin.String>? = null,
 
+    @param:JsonProperty("string_nullable")
     @get:JsonProperty("string_nullable")
     val stringNullable: kotlin.String? = null
 

samples/client/echo_api/kotlin-jvm-spring-3-webclient/src/main/kotlin/org/openapitools/client/models/NumberPropertiesOnly.kt

@@ -38,12 +38,15 @@ import com.fasterxml.jackson.annotation.JsonProperty
 
 data class NumberPropertiesOnly (
 
+    @param:JsonProperty("number")
     @get:JsonProperty("number")
     val number: java.math.BigDecimal? = null,
 
+    @param:JsonProperty("float")
     @get:JsonProperty("float")
     val float: kotlin.Float? = null,
 
+    @param:JsonProperty("double")
     @get:JsonProperty("double")
     val double: kotlin.Double? = null