Set UTF-8 as default multipart charset to ContentRequestMatchers

See gh-31924

Author: azdanov

Diff for: spring-test/src/main/java/org/springframework/test/web/client/match/ContentRequestMatchers.java

@@ -60,6 +60,8 @@
  */
 public class ContentRequestMatchers {
 
+	private static final String DEFAULT_ENCODING = "UTF-8";
+
 	private final XmlExpectationsHelper xmlHelper;
 
 	private final JsonExpectationsHelper jsonHelper;
@@ -367,7 +369,9 @@ private static class MultipartHelper {
 		public static MultiValueMap<String, ?> parse(MockClientHttpRequest request) {
 			try {
 				FileUpload fileUpload = new FileUpload();
-				fileUpload.setFileItemFactory(new DiskFileItemFactory());
+				DiskFileItemFactory factory = new DiskFileItemFactory();
+				factory.setDefaultCharset(DEFAULT_ENCODING);
+				fileUpload.setFileItemFactory(factory);
 
 				List<FileItem> fileItems = fileUpload.parseRequest(new UploadContext() {
 					private final byte[] body = request.getBodyAsBytes();

Diff for: spring-test/src/test/java/org/springframework/test/web/client/match/ContentRequestMatchersTests.java

@@ -18,6 +18,7 @@
 
 import java.nio.charset.StandardCharsets;
 import java.util.Collections;
+import java.util.Map;
 
 import org.junit.jupiter.api.Test;
 
@@ -124,6 +125,72 @@ public void testFormDataContains() throws Exception {
 				.match(this.request);
 	}
 
+	@Test
+	public void testMultipartData() throws Exception {
+		String contentType = "multipart/form-data;boundary=1234567890";
+		String body = "--1234567890\r\n" +
+				"Content-Disposition: form-data; name=\"name 1\"\r\n" +
+				"\r\n" +
+				"vølue 1\r\n" +
+				"--1234567890\r\n" +
+				"Content-Disposition: form-data; name=\"name 2\"\r\n" +
+				"\r\n" +
+				"value 🙂\r\n" +
+				"--1234567890\r\n" +
+				"Content-Disposition: form-data; name=\"name 3\"\r\n" +
+				"\r\n" +
+				"value 漢字\r\n" +
+				"--1234567890\r\n" +
+				"Content-Disposition: form-data; name=\"name 4\"\r\n" +
+				"\r\n" +
+				"\r\n" +
+				"--1234567890--\r\n";
+
+		this.request.getHeaders().setContentType(MediaType.parseMediaType(contentType));
+		this.request.getBody().write(body.getBytes(StandardCharsets.UTF_8));
+
+		MultiValueMap<String, String> map = new LinkedMultiValueMap<>();
+		map.add("name 1", "vølue 1");
+		map.add("name 2", "value 🙂");
+		map.add("name 3", "value 漢字");
+		map.add("name 4", "");
+		MockRestRequestMatchers.content().multipartData(map).match(this.request);
+	}
+
+	@Test
+	public void testMultipartDataContains() throws Exception {
+		String contentType = "multipart/form-data;boundary=1234567890";
+		String body = "--1234567890\r\n" +
+				"Content-Disposition: form-data; name=\"name 1\"\r\n" +
+				"\r\n" +
+				"vølue 1\r\n" +
+				"--1234567890\r\n" +
+				"Content-Disposition: form-data; name=\"name 2\"\r\n" +
+				"\r\n" +
+				"value 🙂\r\n" +
+				"--1234567890\r\n" +
+				"Content-Disposition: form-data; name=\"name 3\"\r\n" +
+				"\r\n" +
+				"value 漢字\r\n" +
+				"--1234567890\r\n" +
+				"Content-Disposition: form-data; name=\"name 4\"\r\n" +
+				"\r\n" +
+				"\r\n" +
+				"--1234567890--\r\n";
+
+		this.request.getHeaders().setContentType(MediaType.parseMediaType(contentType));
+		this.request.getBody().write(body.getBytes(StandardCharsets.UTF_8));
+
+		MockRestRequestMatchers.content()
+				.multipartDataContains(Map.of(
+						"name 1", "vølue 1",
+						"name 2", "value 🙂",
+						"name 3", "value 漢字",
+						"name 4", "")
+				)
+				.match(this.request);
+	}
+
 	@Test
 	public void testXml() throws Exception {
 		String content = "<foo><bar>baz</bar><bar>bazz</bar></foo>";