Refactor error handling for empty JSON and XML payloads

ballerina/Ballerina.toml

@@ -1,7 +1,7 @@
 [package]
 org = "ballerina"
 name = "mime"
-version = "2.12.0"
+version = "2.12.1"
 authors = ["Ballerina"]
 keywords = ["mime", "multipart", "entity"]
 repository = "https://github.com/ballerina-platform/module-ballerina-mime"
@@ -15,11 +15,11 @@ graalvmCompatible = true
 [[platform.java21.dependency]]
 groupId = "io.ballerina.stdlib"
 artifactId = "mime-native"
-version = "2.12.0"
-path = "../native/build/libs/mime-native-2.12.0.jar"
+version = "2.12.1"
+path = "../native/build/libs/mime-native-2.12.1-SNAPSHOT.jar"
 
 [[platform.java21.dependency]]
-path = "../test-utils/build/libs/mime-test-utils-2.12.0.jar"
+path = "../test-utils/build/libs/mime-test-utils-2.12.1-SNAPSHOT.jar"
 scope = "testOnly"
 
 [[platform.java21.dependency]]

ballerina/Dependencies.toml

@@ -120,7 +120,7 @@ modules = [
 [[package]]
 org = "ballerina"
 name = "mime"
-version = "2.12.0"
+version = "2.12.1"
 dependencies = [
 	{org = "ballerina", name = "io"},
 	{org = "ballerina", name = "jballerina.java"},
@@ -136,7 +136,7 @@ modules = [
 [[package]]
 org = "ballerina"
 name = "observe"
-version = "1.5.0"
+version = "1.5.1"
 dependencies = [
 	{org = "ballerina", name = "jballerina.java"}
 ]

ballerina/tests/mime_test.bal

@@ -1586,6 +1586,71 @@ isolated function getPartsFromInvalidChannel() {
     }
 }
 
+@test:Config {}
+function testEmptyJson1() {
+    Entity entity = new;
+    byte[][] emptyPayload = [];
+    entity.setByteStream(emptyPayload.toStream());
+    json|error content = entity.getJson();
+    if content is json {
+        test:assertFail("Expected an error but got JSON content: " + content.toString());
+    } else {
+        test:assertTrue(content is ParserError);
+        error? cause = content.cause();
+        if cause is () {
+            test:assertFail("Expected a cause for the ParserError but got none.");
+        }
+        test:assertTrue(cause is NoContentError);
+        test:assertEquals(cause.message(), "empty JSON document");
+    }
+}
+
+@test:Config {}
+function testEmptyJson2() {
+    Entity entity = new;
+    entity.setText("");
+    json|error content = entity.getJson();
+    if content is json {
+        test:assertFail("Expected an error but got JSON content: " + content.toString());
+    } else {
+        test:assertTrue(content is ParserError);
+        error? cause = content.cause();
+        if cause is () {
+            test:assertFail("Expected a cause for the ParserError but got none.");
+        }
+        test:assertTrue(cause is NoContentError);
+        test:assertEquals(cause.message(), "empty JSON document");
+    }
+}
+
+@test:Config {}
+function testEmptyXml1() {
+    Entity entity = new;
+    byte[][] emptyPayload = [];
+    entity.setByteStream(emptyPayload.toStream());
+    xml|error content = entity.getXml();
+    if content is xml {
+        test:assertFail("Expected an error but got XML content: " + content.toString());
+    } else {
+        test:assertTrue(content is ParserError);
+        error? cause = content.cause();
+        if cause is () {
+            test:assertFail("Expected a cause for the ParserError but got none.");
+        }
+        test:assertTrue(cause is NoContentError);
+        test:assertTrue(cause.message().includes("Empty xml payload"));
+    }
+}
+
+@test:Config {}
+function testEmptyXml2() {
+    Entity entity = new;
+    entity.setText("");
+    xml|error content = entity.getXml();
+    // XML parser in Ballerina returns empty XML for empty string input
+    test:assertEquals(content, xml ``);
+}
+
 isolated function assertByteArray(byte[]|error returnResult, string expectValue) {
     if returnResult is byte[] {
         var value = strings:fromBytes(returnResult);

changelog.md

@@ -4,6 +4,12 @@ This file contains all the notable changes done to the Ballerina MIME package th
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/), and this project adheres to 
 [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+### Fixed
+
+- [Add no content error for runtime parser no content exception](https://github.com/ballerina-platform/ballerina-library/issues/8475)
+
 ## [2.11.0] - 2025-02-11
 - This version maintains the latest dependency versions.
 

native/src/main/java/io/ballerina/stdlib/mime/nativeimpl/MimeDataSourceBuilder.java

@@ -20,10 +20,8 @@
 
 import io.ballerina.runtime.api.creators.ValueCreator;
 import io.ballerina.runtime.api.types.Type;
-import io.ballerina.runtime.api.utils.JsonUtils;
 import io.ballerina.runtime.api.utils.StringUtils;
 import io.ballerina.runtime.api.utils.TypeUtils;
-import io.ballerina.runtime.api.utils.XmlUtils;
 import io.ballerina.runtime.api.values.BArray;
 import io.ballerina.runtime.api.values.BError;
 import io.ballerina.runtime.api.values.BObject;
@@ -43,6 +41,8 @@
 import static io.ballerina.stdlib.mime.util.MimeConstants.ENTITY_BYTE_CHANNEL;
 import static io.ballerina.stdlib.mime.util.MimeConstants.PARSER_ERROR;
 import static io.ballerina.stdlib.mime.util.MimeUtil.isNotNullAndEmpty;
+import static io.ballerina.stdlib.mime.util.MimeUtil.parseAsJson;
+import static io.ballerina.stdlib.mime.util.MimeUtil.parseAsXml;
 
 /**
  * Utilities related to MIME entity body that can be built as a data source.
@@ -106,7 +106,7 @@ protected static Object getAlreadyBuiltJson(Object dataSource) {
         } else {
             // Else, build the JSON from the string representation of the payload.
             String payload = MimeUtil.getMessageAsString(dataSource);
-            result = (BRefValue) JsonUtils.parse(payload);
+            result = (BRefValue) parseAsJson(payload);
         }
         return result;
     }
@@ -155,7 +155,7 @@ protected static Object getAlreadyBuiltXml(Object dataSource) {
         }
         // Build the XML from string representation of the payload.
         String payload = MimeUtil.getMessageAsString(dataSource);
-        return XmlUtils.parse(payload);
+        return parseAsXml(payload);
     }
 
     protected static void updateDataSource(BObject entityObj, Object result) {

native/src/main/java/io/ballerina/stdlib/mime/util/EntityBodyHandler.java

@@ -25,10 +25,8 @@
 import io.ballerina.runtime.api.types.ArrayType;
 import io.ballerina.runtime.api.types.ObjectType;
 import io.ballerina.runtime.api.types.Type;
-import io.ballerina.runtime.api.utils.JsonUtils;
 import io.ballerina.runtime.api.utils.StringUtils;
 import io.ballerina.runtime.api.utils.TypeUtils;
-import io.ballerina.runtime.api.utils.XmlUtils;
 import io.ballerina.runtime.api.values.BArray;
 import io.ballerina.runtime.api.values.BError;
 import io.ballerina.runtime.api.values.BMap;
@@ -60,6 +58,10 @@
 import static io.ballerina.stdlib.mime.util.MimeConstants.MESSAGE_DATA_SOURCE;
 import static io.ballerina.stdlib.mime.util.MimeConstants.MULTIPART_AS_PRIMARY_TYPE;
 import static io.ballerina.stdlib.mime.util.MimeConstants.TEXT_EVENT_STREAM;
+import static io.ballerina.stdlib.mime.util.MimeUtil.EMPTY_JSON_DOCUMENT;
+import static io.ballerina.stdlib.mime.util.MimeUtil.EMPTY_XML_PAYLOAD;
+import static io.ballerina.stdlib.mime.util.MimeUtil.parseAsJson;
+import static io.ballerina.stdlib.mime.util.MimeUtil.parseAsXml;
 
 /**
  * Entity body related operations are included here.
@@ -170,7 +172,7 @@ public static BArray constructBlobDataSource(InputStream inputStream) {
     public static Object constructJsonDataSource(BObject entityObj) {
         Channel byteChannel = getByteChannel(entityObj);
         if (byteChannel == null) {
-            throw MimeUtil.createError(MimeConstants.NO_CONTENT_ERROR, "empty JSON document");
+            throw MimeUtil.createError(MimeConstants.NO_CONTENT_ERROR, EMPTY_JSON_DOCUMENT);
         }
         try {
             return constructJsonDataSource(entityObj, byteChannel.getInputStream());
@@ -194,12 +196,12 @@ public static Object constructJsonDataSource(BObject entity, InputStream inputSt
         if (MimeUtil.isNotNullAndEmpty(contentTypeValue)) {
             String charsetValue = MimeUtil.getContentTypeParamValue(contentTypeValue, CHARSET);
             if (MimeUtil.isNotNullAndEmpty(charsetValue)) {
-                jsonData = JsonUtils.parse(inputStream, charsetValue);
+                jsonData = parseAsJson(inputStream, charsetValue);
             } else {
-                jsonData = JsonUtils.parse(inputStream);
+                jsonData = parseAsJson(inputStream);
             }
         } else {
-            jsonData = JsonUtils.parse(inputStream);
+            jsonData = parseAsJson(inputStream);
         }
         return jsonData;
     }
@@ -213,7 +215,7 @@ public static Object constructJsonDataSource(BObject entity, InputStream inputSt
     public static BXml constructXmlDataSource(BObject entityObj) {
         Channel byteChannel = getByteChannel(entityObj);
         if (byteChannel == null) {
-            throw MimeUtil.createError(MimeConstants.NO_CONTENT_ERROR, "Empty xml payload");
+            throw MimeUtil.createError(MimeConstants.NO_CONTENT_ERROR, EMPTY_XML_PAYLOAD);
         }
         try {
             return constructXmlDataSource(entityObj, byteChannel.getInputStream());
@@ -237,12 +239,12 @@ public static BXml constructXmlDataSource(BObject entityObj, InputStream inputSt
         if (MimeUtil.isNotNullAndEmpty(contentTypeValue)) {
             String charsetValue = MimeUtil.getContentTypeParamValue(contentTypeValue, CHARSET);
             if (MimeUtil.isNotNullAndEmpty(charsetValue)) {
-                xmlContent = XmlUtils.parse(inputStream, charsetValue);
+                xmlContent = parseAsXml(inputStream, charsetValue);
             } else {
-                xmlContent = XmlUtils.parse(inputStream);
+                xmlContent = parseAsXml(inputStream);
             }
         } else {
-            xmlContent = XmlUtils.parse(inputStream);
+            xmlContent = parseAsXml(inputStream);
         }
         return xmlContent;
     }

native/src/main/java/io/ballerina/stdlib/mime/util/MimeUtil.java

@@ -25,14 +25,17 @@
 import io.ballerina.runtime.api.types.PredefinedTypes;
 import io.ballerina.runtime.api.types.Type;
 import io.ballerina.runtime.api.types.TypeTags;
+import io.ballerina.runtime.api.utils.JsonUtils;
 import io.ballerina.runtime.api.utils.StringUtils;
 import io.ballerina.runtime.api.utils.TypeUtils;
+import io.ballerina.runtime.api.utils.XmlUtils;
 import io.ballerina.runtime.api.values.BArray;
 import io.ballerina.runtime.api.values.BError;
 import io.ballerina.runtime.api.values.BMap;
 import io.ballerina.runtime.api.values.BObject;
 import io.ballerina.runtime.api.values.BStreamingJson;
 import io.ballerina.runtime.api.values.BString;
+import io.ballerina.runtime.api.values.BXml;
 import io.ballerina.stdlib.mime.nativeimpl.ModuleUtils;
 import jakarta.activation.MimeType;
 import jakarta.activation.MimeTypeParameterList;
@@ -44,6 +47,7 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
 import java.util.Enumeration;
 import java.util.Random;
@@ -86,6 +90,10 @@
 public class MimeUtil {
     private static final Logger LOG = LoggerFactory.getLogger(MimeUtil.class);
 
+    public static final String EMPTY_JSON_DOCUMENT = "empty JSON document";
+    public static final String EMPTY_XML_PAYLOAD = "Empty xml payload";
+    public static final String UNEXPECTED_EOF_IN_PROLOG = "Unexpected EOF in prolog";
+
     /**
      * Given a ballerina entity, get the content-type as a base type.
      *
@@ -518,6 +526,70 @@ private static boolean parseAsJson(BObject entity) {
         return parseAsJson != null && (boolean) entity.getNativeData(MimeConstants.PARSE_AS_JSON);
     }
 
+    public static Object parseAsJson(InputStream inputStream) {
+        return parseAsJson(inputStream, Charset.defaultCharset().name());
+    }
+
+    public static Object parseAsJson(InputStream inputStream, String charset) {
+        try {
+            return JsonUtils.parse(inputStream, charset);
+        } catch (BError parserError) {
+            handleJsonParseError(parserError);
+            throw parserError;
+        }
+    }
+
+    public static Object parseAsJson(String jsonString) {
+        try {
+            return JsonUtils.parse(jsonString);
+        } catch (BError parserError) {
+            handleJsonParseError(parserError);
+            throw parserError;
+        }
+    }
+
+    public static BXml parseAsXml(InputStream inputStream) {
+        return parseAsXml(inputStream, Charset.defaultCharset().name());
+    }
+
+    public static BXml parseAsXml(InputStream inputStream, String charsetValue) {
+        try {
+            return XmlUtils.parse(inputStream, charsetValue);
+        } catch (BError parserError) {
+            handleXmlParseError(parserError);
+            throw parserError;
+        }
+    }
+
+    public static BXml parseAsXml(String xmlString) {
+        try {
+            return XmlUtils.parse(xmlString);
+        } catch (BError parserError) {
+            handleXmlParseError(parserError);
+            throw parserError;
+        }
+    }
+
+    private static void handleJsonParseError(BError parserError) {
+        String errorMsg = parserError.getMessage();
+        // This EMPTY_JSON_DOCUMENT error occurs when the JSON payload is empty.
+        // Currently, the lang lib JSON parser does not have a specific error for empty JSON payloads.
+        // Therefore, we are checking for this specific error message to identify empty JSON payloads.
+        if (errorMsg != null && errorMsg.startsWith(EMPTY_JSON_DOCUMENT)) {
+            throw MimeUtil.createError(MimeConstants.NO_CONTENT_ERROR, EMPTY_JSON_DOCUMENT, parserError);
+        }
+    }
+
+    private static void handleXmlParseError(BError parserError) {
+        String errorMsg = parserError.getMessage();
+        // This UNEXPECTED_EOF_IN_PROLOG error occurs when the XML payload is empty.
+        // Currently, the lang lib XML parser does not have a specific error for empty XML payloads.
+        // Therefore, we are checking for this specific error message to identify empty XML payloads.
+        if (errorMsg != null && errorMsg.contains(UNEXPECTED_EOF_IN_PROLOG)) {
+            throw MimeUtil.createError(MimeConstants.NO_CONTENT_ERROR, EMPTY_XML_PAYLOAD, parserError);
+        }
+    }
+
     /**
      * Validate the given Content-Type.
      *