[master] Fix bug when return type is byte[] in OpenAPI spec generation

openapi-bal-service/src/main/java/io/ballerina/openapi/converter/Constants.java

@@ -46,6 +46,7 @@ public class Constants {
     public static final String TYPEREFERENCE = "typeReference";
     public static final String HTTP_HEADER = "http:Header";
     public static final String BYTE_ARRAY = "byte[]";
+    public static final String BYTE = "byte";
     public static final String OCTET_STREAM = "octet-stream";
     public static final String XML = "xml";
     public static final String JSON = "json";

openapi-bal-service/src/main/java/io/ballerina/openapi/converter/service/OpenAPIResponseMapper.java

@@ -94,6 +94,8 @@
 import static io.ballerina.compiler.syntax.tree.SyntaxKind.TYPE_REFERENCE;
 import static io.ballerina.openapi.converter.Constants.APPLICATION_PREFIX;
 import static io.ballerina.openapi.converter.Constants.BODY;
+import static io.ballerina.openapi.converter.Constants.BYTE;
+import static io.ballerina.openapi.converter.Constants.BYTE_ARRAY;
 import static io.ballerina.openapi.converter.Constants.CACHE_CONTROL;
 import static io.ballerina.openapi.converter.Constants.ETAG;
 import static io.ballerina.openapi.converter.Constants.FALSE;
@@ -621,6 +623,7 @@ private Optional<ApiResponses> getApiResponsesForArrayTypes(OperationAdaptor ope
             ArraySchema arraySchema = new ArraySchema();
             String type02 = array.memberTypeDesc().kind().toString().trim().split("_")[0].
                     toLowerCase(Locale.ENGLISH);
+            type02 = type02.equals(BYTE) ? BYTE_ARRAY : type02;
             Schema<?> openApiSchema = ConverterCommonUtils.getOpenApiSchema(type02);
             Optional<String> mimeType = convertBallerinaMIMEToOASMIMETypes(type02, customMediaPrefix);
             if (mimeType.isEmpty()) {

openapi-cli/src/test/java/io/ballerina/openapi/generators/openapi/ResponseTests.java

@@ -256,6 +256,16 @@ public void testResponseWithDecimalReturnType() throws IOException {
         compareWithGeneratedFile(ballerinaFilePath, "response/decimal.yaml");
     }
 
+    @Test(description = "When the response has byte[] return type")
+    public void testResponseWithByteArray() throws IOException {
+        Path ballerinaFilePath = RES_DIR.resolve("response/byte.bal");
+        OASContractGenerator openApiConverterUtils = new OASContractGenerator();
+        openApiConverterUtils.generateOAS3DefinitionsAllService(ballerinaFilePath, this.tempDir, null
+                , false);
+        Assert.assertTrue(openApiConverterUtils.getErrors().isEmpty());
+        compareWithGeneratedFile(ballerinaFilePath, "response/byte.yaml");
+    }
+
     @Test
     public void testWithMultipleReturnPayloadSameStatusCode() throws IOException {
         Path ballerinaFilePath = RES_DIR.resolve("response/same_status_code.bal");

openapi-cli/src/test/resources/ballerina-to-openapi/expected_gen/response/byte.yaml

@@ -0,0 +1,61 @@
+openapi: 3.0.1
+info:
+  title: PayloadV
+  version: 0.0.0
+servers:
+  - url: "{server}:{port}/payloadV"
+    variables:
+      server:
+        default: http://localhost
+      port:
+        default: "9090"
+paths:
+  /challenges/{challenged}:
+    get:
+      operationId: getChallengesChallenged
+      parameters:
+        - name: challenged
+          in: path
+          required: true
+          schema:
+            type: string
+      responses:
+        "200":
+          description: Ok
+          content:
+            application/octet-stream:
+              schema:
+                type: array
+                items:
+                  type: string
+                  format: uuid
+        "500":
+          description: Internal server error
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/ErrorPayload'
+components:
+  schemas:
+    ErrorPayload:
+      type: object
+      properties:
+        reason:
+          type: string
+          description: Reason phrase
+        path:
+          type: string
+          description: Request path
+        method:
+          type: string
+          description: Method type of the request
+        message:
+          type: string
+          description: Error message
+        timestamp:
+          type: string
+          description: Timestamp of the error
+        status:
+          type: integer
+          description: Relevant HTTP status code
+          format: int32

openapi-cli/src/test/resources/ballerina-to-openapi/response/byte.bal

@@ -0,0 +1,15 @@
+import ballerina/http;
+
+public type ReturnValueXML xml;
+
+public type ReturnValueCustomRec record {|
+    *http:BadGateway;
+    ReturnValueXML body;
+|};
+
+service /payloadV on new http:Listener(9090) {
+
+    resource function get challenges/[string challenged]() returns byte[]|error {
+        return error("");
+    }
+}