Add test case

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

@@ -61,6 +61,12 @@ public void testForTupleType() throws IOException {
         TestUtils.compareWithGeneratedFile(ballerinaFilePath, "data_type/tuple_type.yaml");
     }
 
+    @Test(description = "test for Ballerina built-in subtypes as record fields")
+    public void testForBuiltInSubTypes() throws IOException {
+        Path ballerinaFilePath = RES_DIR.resolve("data_type/built_in_sub_types_in_record.bal");
+        TestUtils.compareWithGeneratedFile(ballerinaFilePath, "data_type/built_in_sub_types_in_record.yaml");
+    }
+
     @AfterMethod
     public void cleanUp() {
         TestUtils.deleteDirectory(this.tempDir);

openapi-cli/src/test/resources/ballerina-to-openapi/data_type/built_in_sub_types_in_record.bal

@@ -0,0 +1,58 @@
+import ballerina/http;
+
+public type BalSignedInts record {|
+    int:Signed32 signed32;
+    int:Signed16 signed16;
+    int:Signed8 signed8;
+|};
+
+public type BalUnsignedInts record {|
+    int:Unsigned32 unsigned32;
+    int:Unsigned16 unsigned16;
+    int:Unsigned8 unsigned8;
+|};
+
+public type BalInts record {|
+    BalSignedInts signed;
+    BalUnsignedInts unsigned;
+|};
+
+public type BalXmls record {|
+    xml:Comment comment;
+    xml:Element element;
+    xml:ProcessingInstruction processingInstruction;
+    xml:Text text;
+|};
+
+public type BalSubTypes record {|
+    string:Char char;
+    BalInts ints;
+    BalXmls xmls;
+|};
+
+service /payloadV on new http:Listener(9090) {
+
+    resource function get path() returns BalSubTypes {
+        return {
+            char: "a",
+            ints: {
+                signed: {
+                    signed32: 32,
+                    signed16: 16,
+                    signed8: 8
+                },
+                unsigned: {
+                    unsigned32: 32,
+                    unsigned16: 16,
+                    unsigned8: 8
+                }
+            },
+            xmls: {
+                comment: xml`<!-- comment -->`,
+                element: xml`<element>element</element>`,
+                processingInstruction: xml`<?processing instruction?>`,
+                text: xml`text`
+            }
+        };
+    }
+}

openapi-cli/src/test/resources/ballerina-to-openapi/expected_gen/data_type/built_in_sub_types_in_record.yaml

@@ -0,0 +1,90 @@
+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:
+  /path:
+    get:
+      operationId: getPath
+      responses:
+        "200":
+          description: Ok
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/BalSubTypes'
+components:
+  schemas:
+    BalSubTypes:
+      required:
+        - char
+        - ints
+        - xmls
+      type: object
+      properties:
+        char:
+          type: string
+        ints:
+          $ref: '#/components/schemas/BalInts'
+        xmls:
+          $ref: '#/components/schemas/BalXmls'
+    BalUnsignedInts:
+      required:
+        - unsigned16
+        - unsigned32
+        - unsigned8
+      type: object
+      properties:
+        unsigned32:
+          type: integer
+        unsigned16:
+          type: integer
+        unsigned8:
+          type: integer
+    BalXmls:
+      required:
+        - comment
+        - element
+        - processingInstruction
+        - text
+      type: object
+      properties:
+        comment:
+          type: object
+        element:
+          type: object
+        processingInstruction:
+          type: object
+        text:
+          type: object
+    BalInts:
+      required:
+        - signed
+        - unsigned
+      type: object
+      properties:
+        signed:
+          $ref: '#/components/schemas/BalSignedInts'
+        unsigned:
+          $ref: '#/components/schemas/BalUnsignedInts'
+    BalSignedInts:
+      required:
+        - signed16
+        - signed32
+        - signed8
+      type: object
+      properties:
+        signed32:
+          type: integer
+          format: int32
+        signed16:
+          type: integer
+        signed8:
+          type: integer