feat: x-enum-description support added to kotlin-server code generator (#19041)

Author: deicon

modules/openapi-generator/src/main/resources/kotlin-server/enum_class.mustache

@@ -4,6 +4,11 @@
 */
 enum class {{classname}}(val value: {{dataType}}) {
 {{#allowableValues}}{{#enumVars}}
+    {{#enumDescription}}
+    /**
+    * {{.}}
+    */
+    {{/enumDescription}}
     {{&name}}({{{value}}}){{^-last}},{{/-last}}{{#-last}};{{/-last}}
 {{/enumVars}}{{/allowableValues}}
 }

modules/openapi-generator/src/main/resources/kotlin-server/libraries/jaxrs-spec/enum_class.mustache

@@ -13,6 +13,12 @@ import kotlinx.serialization.Serializable
 {{>additionalModelTypeAnnotations}}
 {{#nonPublicApi}}internal {{/nonPublicApi}}enum class {{classname}}(val value: {{{dataType}}}) {
 {{#allowableValues}}{{#enumVars}}
+
+    {{#enumDescription}}
+    /**
+    * {{.}}
+    */
+    {{/enumDescription}}
     @JsonProperty(value = {{^isString}}"{{/isString}}{{{value}}}{{^isString}}"{{/isString}})
     {{#kotlinx_serialization}}
     @SerialName(value = {{^isString}}"{{/isString}}{{{value}}}{{^isString}}"{{/isString}})

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

@@ -23,6 +23,38 @@
 
 public class KotlinServerCodegenTest {
 
+
+    @Test
+    public void enumDescription() throws IOException {
+        File output = Files.createTempDirectory("test").toFile().getCanonicalFile();
+        output.deleteOnExit();
+
+        KotlinServerCodegen codegen = new KotlinServerCodegen();
+        codegen.setOutputDir(output.getAbsolutePath());
+        codegen.additionalProperties().put(LIBRARY, JAXRS_SPEC);
+
+        new DefaultGenerator().opts(new ClientOptInput()
+                        .openAPI(TestUtils.parseSpec("src/test/resources/3_0/enum-description.yaml"))
+                        .config(codegen))
+                .generate();
+
+        String outputPath = output.getAbsolutePath() + "/src/main/kotlin/org/openapitools/server";
+        Path petApi = Paths.get(outputPath + "/models/Type.kt");
+        assertFileNotContains(
+                petApi,
+                "import jakarta.ws.rs.*",
+                "import jakarta.ws.rs.core.Response",
+                "@jakarta.annotation.Generated(value = arrayOf(\"org.openapitools.codegen.languages.KotlinServerCodegen\")"
+        );
+        // assert, that all enum values have a description comment
+        assertFileContains(
+                petApi,
+                "Pegasi b is a gas giant exoplanet that orbits a G-type star",
+                "Mercury is the first planet from the Sun and the smallest in the Solar System",
+                "The planet we all live on"
+        );
+    }
+
     @Test
     public void javaxImports() throws IOException {
         File output = Files.createTempDirectory("test").toFile().getCanonicalFile();

modules/openapi-generator/src/test/resources/3_0/enum-description.yaml

@@ -0,0 +1,36 @@
+openapi: 3.0.0
+info:
+  title: Sample API
+  description: API description in Markdown.
+  version: 1.0.0
+paths:
+  /ponies:
+    get:
+      summary: Returns all animals.
+      description: Optional extended description in Markdown.
+      responses:
+        200:
+          description: OK
+          content:
+            application/json:
+              schema:
+                type: array
+                items:
+                  $ref: '#/components/schemas/Pony'
+components:
+  schemas:
+    Pony:
+      type: object
+      properties:
+        type:
+          $ref: '#/components/schemas/Type'
+    Type:
+      type: string
+      enum:
+        - Earth
+        - Pegasi
+        - Mercury
+      x-enum-descriptions:
+        - The planet we all live on
+        - Pegasi b is a gas giant exoplanet that orbits a G-type star
+        - Mercury is the first planet from the Sun and the smallest in the Solar System