strip quotes in storage emulator header boundary (#4825)

Author: Yuangwang

CHANGELOG.md

@@ -1,2 +1,3 @@
 - Replaces underlying terminal coloring library.
+- Make storage emulator multipart parsing handle quotes in boundary header #3953
 - Make storage emulator content type case insensitive #3953

src/emulator/storage/multipart.ts

@@ -51,7 +51,9 @@ function splitBufferByDelimiter(buffer: Buffer, delimiter: string, maxResults =
  * @param body multipart request body as a Buffer
  */
 function parseMultipartRequestBody(boundaryId: string, body: Buffer): MultipartRequestBody {
-  const boundaryString = `--${boundaryId}`;
+  // strip additional surrounding single and double quotes, cloud sdks have additional quote here
+  const cleanBoundaryId = boundaryId.replace(/^["'](.+(?=["']$))["']$/, "$1");
+  const boundaryString = `--${cleanBoundaryId}`;
   const bodyParts = splitBufferByDelimiter(body, boundaryString).map((buf) => {
     // Remove the \r\n and the beginning of each part left from the boundary line.
     return Buffer.from(buf.slice(2));

src/test/emulators/storage/multipart.spec.ts

@@ -78,6 +78,28 @@ hello there!
       );
     });
 
+    it("parses an upload object multipart request with additional quotes in the boundary value", () => {
+      const contentTypeHeaderWithDoubleQuotes = `multipart/related; boundary="b1d5b2e3-1845-4338-9400-6ac07ce53c1e"`;
+
+      let { metadataRaw, dataRaw } = parseObjectUploadMultipartRequest(
+        contentTypeHeaderWithDoubleQuotes,
+        BODY
+      );
+
+      expect(metadataRaw).to.equal('{"contentType":"text/plain"}');
+      expect(dataRaw.toString()).to.equal("hello there!\n");
+
+      const contentTypeHeaderWithSingleQuotes = `multipart/related; boundary='b1d5b2e3-1845-4338-9400-6ac07ce53c1e'`;
+
+      ({ metadataRaw, dataRaw } = parseObjectUploadMultipartRequest(
+        contentTypeHeaderWithSingleQuotes,
+        BODY
+      ));
+
+      expect(metadataRaw).to.equal('{"contentType":"text/plain"}');
+      expect(dataRaw.toString()).to.equal("hello there!\n");
+    });
+
     it("fails to parse when body has wrong number of parts", () => {
       const invalidBody = Buffer.from(`--b1d5b2e3-1845-4338-9400-6ac07ce53c1e\r
 Content-Type: application/json\r