feat: add support for filename in Content-Disposition header

* feat: implement filename support in Content-Disposition header
* test: add test cases for filename in Content-Disposition

Author: tggoo

packages/abstractions/src/multipartBody.ts

@@ -27,8 +27,9 @@ export class MultipartBody implements Parsable {
 	 * @param partContentType the content type of the part to add or replace.
 	 * @param content the content of the part to add or replace.
 	 * @param serializationCallback the serialization callback to use when serializing the part.
+	 * @param fileName the name of the file associated with this part.
 	 */
-	public addOrReplacePart<T>(partName: string, partContentType: string, content: T, serializationCallback?: ModelSerializerFunction<Parsable>): void {
+	public addOrReplacePart<T>(partName: string, partContentType: string, content: T, serializationCallback?: ModelSerializerFunction<Parsable>, fileName?: string): void {
 		if (!partName) throw new Error("partName cannot be undefined");
 		if (!partContentType) {
 			throw new Error("partContentType cannot be undefined");
@@ -39,6 +40,7 @@ export class MultipartBody implements Parsable {
 			contentType: partContentType,
 			content,
 			originalName: partName,
+			fileName,
 			serializationCallback,
 		};
 	}
@@ -90,6 +92,7 @@ interface MultipartEntry {
 	contentType: string;
 	content: any;
 	originalName: string;
+	fileName?: string;
 	serializationCallback?: ModelSerializerFunction<Parsable>;
 }
 
@@ -124,7 +127,7 @@ export const serializeMultipartBody = (writer: SerializationWriter, multipartBod
 			const part = parts[partName];
 			writer.writeStringValue("Content-Type", part.contentType);
 			writer.writeStringValue(undefined, "\r\n");
-			writer.writeStringValue("Content-Disposition", 'form-data; name="' + part.originalName + '"');
+			writer.writeStringValue("Content-Disposition", `form-data; name="${part.originalName}"${part.fileName ? `; filename="${part.fileName}"` : ""}`);
 			writer.writeStringValue(undefined, "\r\n");
 			writer.writeStringValue(undefined, "\r\n");
 			if (typeof part.content === "string") {

packages/abstractions/test/common/multipartBody.ts

@@ -40,3 +40,31 @@ describe("multipartBody", () => {
 	});
 	//serialize method is tested in the serialization library
 });
+
+describe("multipartBody with fileName", () => {
+	const arrayBuffer = new Uint8Array([0x01, 0x01, 0x01]);
+	const arrayBuffer2 = new Uint8Array([0x02, 0x02, 0x02]);
+
+	it("adds parts with a filename", () => {
+		const mpBody = new MultipartBody();
+		mpBody.addOrReplacePart("filepart", "application/octet-stream", arrayBuffer, undefined, "file.txt");
+
+		const part = mpBody.listParts()["filepart"];
+		assert.exists(part);
+		assert.strictEqual(part.contentType, "application/octet-stream");
+		assert.strictEqual(part.content, arrayBuffer);
+		assert.strictEqual(part.fileName, "file.txt");
+	});
+
+	it("updates filename when replacing a part", () => {
+		const mpBody = new MultipartBody();
+		mpBody.addOrReplacePart("filepart", "application/octet-stream", arrayBuffer, undefined, "file.txt");
+		mpBody.addOrReplacePart("filepart", "application/pdf", arrayBuffer2, undefined, "document.pdf");
+
+		const part = mpBody.listParts()["filepart"];
+		assert.exists(part);
+		assert.strictEqual(part.fileName, "document.pdf");
+		assert.strictEqual(part.content, arrayBuffer2);
+		assert.strictEqual(part.contentType, "application/pdf");
+	});
+});

packages/serialization/multipart/test/common/multipartSerializationWriter.ts

@@ -122,4 +122,17 @@ describe("MultipartSerializationWriter", () => {
 		const multipartSerializationWriter = new MultipartSerializationWriter();
 		assert.throw(() => multipartSerializationWriter.writeCollectionOfObjectValues(undefined, [testEntity]));
 	});
+
+	it("serializes Content-Disposition with filename", () => {
+		const mpBody = new MultipartBody();
+		mpBody.addOrReplacePart("file", "application/octet-stream", byteForTest, undefined, "file.txt");
+
+		const multipartSerializationWriter = new MultipartSerializationWriter();
+		multipartSerializationWriter.writeObjectValue(undefined, mpBody, serializeMultipartBody);
+		const multipartContent = multipartSerializationWriter.getSerializedContent();
+		const result = new TextDecoder().decode(multipartContent);
+
+		const expectedString = "--" + mpBody.getBoundary() + '\r\nContent-Type: application/octet-stream\r\nContent-Disposition: form-data; name="file"; filename="file.txt"\r\n\r\n' + new TextDecoder().decode(byteForTest) + "\r\n--" + mpBody.getBoundary() + "--\r\n";
+		assert.equal(result, expectedString);
+	});
 });