tests: re-enable disabled Response.formData test (#11453)

3 files changed, 22 insertions, 25 deletions

diff --git a/cli/tests/unit/fetch_test.ts b/cli/tests/unit/fetch_test.ts
index 24a820dba..45ab2d12c 100644
--- a/cli/tests/unit/fetch_test.ts
+++ b/cli/tests/unit/fetch_test.ts
@@ -275,7 +275,7 @@ unitTest(
         await response.formData();
       },
       TypeError,
-      "Invalid form data",
+      "Body can not be decoded as form data",
     );
   },
 );
diff --git a/cli/tests/unit/response_test.ts b/cli/tests/unit/response_test.ts
index 1faf8991a..c1ef80fb6 100644
--- a/cli/tests/unit/response_test.ts
+++ b/cli/tests/unit/response_test.ts
@@ -43,18 +43,17 @@ unitTest(async function responseBlob() {
   assertEquals(await blob.arrayBuffer(), new Uint8Array([1, 2, 3]).buffer);
 });
 
-// TODO(lucacasonato): re-enable test once #10002 is fixed.
-unitTest({ ignore: true }, async function responseFormData() {
+unitTest(async function responseFormData() {
   const input = new FormData();
   input.append("hello", "world");
-  const response = new Response(input, {
-    headers: { "content-type": "application/x-www-form-urlencoded" },
-  });
+  const response = new Response(input);
+  const contentType = response.headers.get("content-type")!;
+  assert(contentType.startsWith("multipart/form-data"));
   const formDataPromise = response.formData();
   assert(formDataPromise instanceof Promise);
   const formData = await formDataPromise;
   assert(formData instanceof FormData);
-  assertEquals(formData, input);
+  assertEquals([...formData], [...input]);
 });
 
 unitTest(function customInspectFunction(): void {
diff --git a/extensions/fetch/22_body.js b/extensions/fetch/22_body.js
index 2a1a91159..97ed57c8b 100644
--- a/extensions/fetch/22_body.js
+++ b/extensions/fetch/22_body.js
@@ -286,27 +286,25 @@
         });
       case "FormData": {
         if (mimeType !== null) {
-          if (mimeType !== null) {
-            const essence = mimesniff.essence(mimeType);
-            if (essence === "multipart/form-data") {
-              const boundary = mimeType.parameters.get("boundary");
-              if (boundary === null) {
-                throw new TypeError(
-                  "Missing boundary parameter in mime type of multipart formdata.",
-                );
-              }
-              return parseFormData(bytes, boundary);
-            } else if (essence === "application/x-www-form-urlencoded") {
-              const entries = parseUrlEncoded(bytes);
-              return formDataFromEntries(
-                ArrayPrototypeMap(
-                  entries,
-                  (x) => ({ name: x[0], value: x[1] }),
-                ),
+          const essence = mimesniff.essence(mimeType);
+          if (essence === "multipart/form-data") {
+            const boundary = mimeType.parameters.get("boundary");
+            if (boundary === null) {
+              throw new TypeError(
+                "Missing boundary parameter in mime type of multipart formdata.",
               );
             }
+            return parseFormData(bytes, boundary);
+          } else if (essence === "application/x-www-form-urlencoded") {
+            const entries = parseUrlEncoded(bytes);
+            return formDataFromEntries(
+              ArrayPrototypeMap(
+                entries,
+                (x) => ({ name: x[0], value: x[1] }),
+              ),
+            );
           }
-          throw new TypeError("Invalid form data");
+          throw new TypeError("Body can not be decoded as form data");
         }
         throw new TypeError("Missing content type");
       }