script: Remove check for zero request body length in FetchLater

Per the spec discussion in [1] we should only check for a length
of `null` and not zero.

[1]: whatwg/fetch#1902

Signed-off-by: Tim van der Lippe <tvanderlippe@gmail.com>

Author: TimvdLippe

components/script/fetch.rs

@@ -394,11 +394,13 @@ pub(crate) fn FetchLater(
     if !url.is_potentially_trustworthy() {
         return Err(Error::Type(c"URL is not trustworthy".to_owned()));
     }
-    // Step 10. If request’s body is not null, and request’s body length is null or zero, then throw a TypeError.
-    if let Some(body) = request.body.as_ref() {
-        if body.len().is_none_or(|len| len == 0) {
-            return Err(Error::Type(c"Body is empty".to_owned()));
-        }
+    // Step 10. If request’s body is not null, and request’s body length is null, then throw a TypeError.
+    if request
+        .body
+        .as_ref()
+        .is_some_and(|body| body.len().is_none())
+    {
+        return Err(Error::Type(c"Body is empty".to_owned()));
     }
     // Step 11. If the available deferred-fetch quota given request’s client and request’s URL’s
     // origin is less than request’s total request length, then throw a "QuotaExceededError" DOMException.

tests/wpt/meta/MANIFEST.json

@@ -714491,7 +714491,7 @@
         ]
        ],
        "empty-payload.https.window.js": [
-        "6c7becfacaf45048c69c815940460d1dbe084a67",
+        "9edf32d179d7f50e849ccca1bb3d766bb586200e",
         [
          "fetch/fetch-later/quota/cross-origin-iframe/empty-payload.https.window.html",
          {
@@ -714640,7 +714640,7 @@
        ]
       },
       "empty-payload.https.window.js": [
-       "c2c4dd50326c0a75b2c82d152995329ccc0cd252",
+       "e7da9053ddbc8739e2bae2b2edb75e85ecd2e483",
        [
         "fetch/fetch-later/quota/empty-payload.https.window.html",
         {
@@ -714767,7 +714767,7 @@
         ]
        ],
        "empty-payload.https.window.js": [
-        "53cae60047eaefd2b01a3bd45c84239fa3752bf9",
+        "c41bf88dd7fe7e61500e7ea673895fe278cbfb6a",
         [
          "fetch/fetch-later/quota/same-origin-iframe/empty-payload.https.window.html",
          {

tests/wpt/tests/fetch/fetch-later/quota/cross-origin-iframe/empty-payload.https.window.js

@@ -8,30 +8,13 @@ const {HTTPS_ORIGIN, HTTPS_NOTSAMESITE_ORIGIN} = get_host_info();
 // In a cross-origin iframe, test making a POST request with empty
 // payload, which is not accepted by fetchLater API.
 for (const dataType in BeaconDataType) {
-  if (dataType === BeaconDataType.FormData) {
-    // An empty FormData object serializes to non-empty String. Hence, there
-    // will be no error thrown from fetchLater.
-    parallelPromiseTest(
-        async _ => await loadFetchLaterIframe(HTTPS_NOTSAMESITE_ORIGIN, {
-          activateAfter: 0,
-          method: 'POST',
-          bodyType: dataType,
-          bodySize: 0,
-        }),
-        `fetchLater() accepts a non-empty POST request body of ${
-            dataType} in a default cross-origin iframe.`);
-    continue;
-  }
-
   parallelPromiseTest(
       async _ => await loadFetchLaterIframe(HTTPS_NOTSAMESITE_ORIGIN, {
         activateAfter: 0,
         method: 'POST',
         bodyType: dataType,
         bodySize: 0,
-        expect: new FetchLaterIframeExpectation(
-            FetchLaterExpectationType.ERROR_JS, TypeError),
       }),
-      `fetchLater() does not accept empty POST request body of ${
+      `fetchLater() accepts a non-empty POST request body of ${
           dataType} in a default cross-origin iframe.`);
 }

tests/wpt/tests/fetch/fetch-later/quota/empty-payload.https.window.js

@@ -14,18 +14,9 @@ for (const dataType in BeaconDataType) {
     body: makeBeaconData('', dataType)
   };
 
-  if (dataType === BeaconDataType.FormData) {
-    // An empty FormData object serializes to non-empty String. Hence, there
-    // will be no error thrown from fetchLater.
-    parallelPromiseTest(async _ => {
-      expectFetchLater(requestInit);
-    }, `fetchLater() accepts a non-empty POST request body of ${dataType}.`);
-    continue;
-  }
-  test(
-      () => assert_throws_js(TypeError, () => fetchLater('/', requestInit)),
-      `fetchLater() does not accept an empty POST request body of ${
-          dataType}.`);
+  parallelPromiseTest(async _ => {
+    expectFetchLater(requestInit);
+  }, `fetchLater() accepts a non-empty POST request body of ${dataType}.`);
 }
 
 // Test making HTTP non-POST requests, which has no payload and should be

tests/wpt/tests/fetch/fetch-later/quota/same-origin-iframe/empty-payload.https.window.js

@@ -8,30 +8,13 @@ const {HTTPS_ORIGIN, HTTPS_NOTSAMESITE_ORIGIN} = get_host_info();
 // In a same-origin iframe, test making a POST request with empty payload,
 // which is not accepted by fetchLater API.
 for (const dataType in BeaconDataType) {
-  if (dataType === BeaconDataType.FormData) {
-    // An empty FormData object serializes to non-empty String. Hence, there
-    // will be no error thrown from fetchLater.
-    parallelPromiseTest(
-        async _ => await loadFetchLaterIframe(HTTPS_ORIGIN, {
-          activateAfter: 0,
-          method: 'POST',
-          bodyType: dataType,
-          bodySize: 0,
-        }),
-        `fetchLater() accepts a non-empty POST request body of ${
-            dataType} in same-origin iframe.`);
-    continue;
-  }
-
   parallelPromiseTest(
       async _ => await loadFetchLaterIframe(HTTPS_ORIGIN, {
         activateAfter: 0,
         method: 'POST',
         bodyType: dataType,
         bodySize: 0,
-        expect: new FetchLaterIframeExpectation(
-            FetchLaterExpectationType.ERROR_JS, TypeError),
       }),
-      `fetchLater() does not accept empty POST request body of ${
+      `fetchLater() accepts a non-empty POST request body of ${
           dataType} in same-origin iframe.`);
 }