Add WPTs for different Early Hints preload finish timings

The test scenarios are:
* 103 -> start preload -> preload finished -> 200 -> response body.
* 103 -> start preload -> (preload inflight) -> 200 -> preload finished
  -> response body.

The purpose of these tests is to make sure the resource is added to the
preload map of the document [1]. Also refer to [2] for the motivation.

[1] whatwg/html#7675
[2] #33076 (comment)

Bug: 1305896
Change-Id: Id0ba4748f6493bc2c78be6de5769b4d16ce9092f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3552176
Reviewed-by: Yutaka Hirano <[email protected]>
Commit-Queue: Kenichi Ishibashi <[email protected]>
Cr-Commit-Position: refs/heads/main@{#985847}

loading/early-hints/preload-finished-before-final-response.h2.window.js

@@ -0,0 +1,11 @@
+// META: script=/common/utils.js
+// META: script=resources/early-hints-helpers.sub.js
+
+test(() => {
+    const params = new URLSearchParams();
+    const id = token();
+    params.set("resource-url", SAME_ORIGIN_RESOURCES_URL + "/fetch-and-record-js.h2.py?id=" + id);
+    params.set("resource-id", id);
+    const test_url = "resources/preload-finished-before-final-response.h2.py?" + params.toString();
+    window.location.replace(new URL(test_url, window.location));
+});

loading/early-hints/preload-finished-while-receiving-final-response-body.h2.window.js

@@ -0,0 +1,11 @@
+// META: script=/common/utils.js
+// META: script=resources/early-hints-helpers.sub.js
+
+test(() => {
+    const params = new URLSearchParams();
+    const id = token();
+    params.set("resource-url", SAME_ORIGIN_RESOURCES_URL + "/fetch-and-record-js.h2.py?id=" + id);
+    params.set("resource-id", id);
+    const test_url = "resources/preload-finished-while-receiving-final-response-body.h2.py?" + params.toString();
+    window.location.replace(new URL(test_url, window.location));
+});

loading/early-hints/resources/delayed-js.h2.py

@@ -1,14 +1,12 @@
-import time
+import importlib
+
+utils = importlib.import_module("loading.early-hints.resources.utils")
 
 
 def main(request, response):
     id = request.GET.first(b"id")
-    url_dir = u'/'.join(request.url_parts.path.split(u'/')[:-1]) + u'/'
     # Wait until the id is set via resume-delayed-js.h2.py.
-    while True:
-        if request.server.stash.take(id, url_dir):
-            break
-        time.sleep(0.1)
+    utils.wait_for_preload_to_finish(request, id)
 
     headers = [
         ("Content-Type", "text/javascript"),

loading/early-hints/resources/fetch-and-record-js.h2.py

@@ -1,4 +1,5 @@
 import importlib
+import time
 
 utils = importlib.import_module("loading.early-hints.resources.utils")
 
@@ -10,4 +11,6 @@ def main(request, response):
         ("Cache-Control", "max-age=600"),
     ]
     body = "/*empty script*/"
+    # Sleep to simulate loading time.
+    time.sleep(0.05)
     return (200, "OK"), headers, body

loading/early-hints/resources/preload-finished-before-final-response.h2.py

@@ -0,0 +1,31 @@
+import importlib
+import os
+
+utils = importlib.import_module("loading.early-hints.resources.utils")
+
+
+def handle_headers(frame, request, response):
+    resource_url = request.GET.first(b"resource-url").decode()
+    link_header_value = "<{}>; rel=preload; as=script".format(resource_url)
+    early_hints = [
+        (b":status", b"103"),
+        (b"link", link_header_value),
+    ]
+    response.writer.write_raw_header_frame(headers=early_hints,
+                                           end_headers=True)
+
+    # Wait for preload to finish before sending the final response headers.
+    resource_id = request.GET.first(b"resource-id").decode()
+    utils.wait_for_preload_to_finish(request, resource_id)
+
+    response.status = 200
+    response.headers[b"content-type"] = "text/html"
+    response.write_status_headers()
+
+
+def main(request, response):
+    current_dir = os.path.dirname(os.path.realpath(__file__))
+    file_path = os.path.join(current_dir, "preload-finished-before-final-response.html")
+    with open(file_path, "r") as f:
+        test_content = f.read()
+    response.writer.write_data(item=test_content, last=True)

loading/early-hints/resources/preload-finished-before-final-response.html

@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="early-hints-helpers.sub.js"></script>
+<body>
+<script>
+promise_test(async (t) => {
+    const params = new URLSearchParams(window.location.search);
+    const resource_url = params.get("resource-url");
+    await fetchScript(resource_url);
+    assert_true(isPreloadedByEarlyHints(resource_url));
+}, "Early hints preload finished before the final response.");
+</script>
+</body>

loading/early-hints/resources/preload-finished-while-receiving-final-response-body.h2.py

@@ -0,0 +1,31 @@
+import importlib
+import os
+
+utils = importlib.import_module("loading.early-hints.resources.utils")
+
+
+def handle_headers(frame, request, response):
+    resource_url = request.GET.first(b"resource-url").decode()
+    link_header_value = "<{}>; rel=preload; as=script".format(resource_url)
+    early_hints = [
+        (b":status", b"103"),
+        (b"link", link_header_value),
+    ]
+    response.writer.write_raw_header_frame(headers=early_hints,
+                                           end_headers=True)
+
+    response.status = 200
+    response.headers[b"content-type"] = "text/html"
+    response.write_status_headers()
+
+
+def main(request, response):
+    # Wait for preload to finish before sending the response body.
+    resource_id = request.GET.first(b"resource-id").decode()
+    utils.wait_for_preload_to_finish(request, resource_id)
+
+    current_dir = os.path.dirname(os.path.realpath(__file__))
+    file_path = os.path.join(current_dir, "preload-finished-while-receiving-final-response-body.html")
+    with open(file_path, "r") as f:
+        test_content = f.read()
+    response.writer.write_data(item=test_content, last=True)

loading/early-hints/resources/preload-finished-while-receiving-final-response-body.html

@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="early-hints-helpers.sub.js"></script>
+<body>
+<script>
+promise_test(async (t) => {
+    const params = new URLSearchParams(window.location.search);
+    const resource_url = params.get("resource-url");
+    await fetchScript(resource_url);
+    assert_true(isPreloadedByEarlyHints(resource_url));
+}, "Early hints preload finished while loading the final response body.");
+</script>
+</body>

loading/early-hints/resources/utils.py

@@ -1,5 +1,6 @@
 import datetime
 import json
+import time
 
 
 def _url_dir(request):
@@ -22,12 +23,23 @@ def store_request_timing_and_headers(request):
     request.server.stash.put(id, value, url_dir)
 
 
-def get_request_timing_and_headers(request):
+def get_request_timing_and_headers(request, id=None):
     """Get previously stored timestamp and request headers associated with the
-    given request. The request must be a GET request and must have the "id"
-    parameter.
+    given "id". When "id" is not given the id is retrieved from "request".
     """
-    id = request.GET.first(b"id")
+    if id is None:
+        id = request.GET.first(b"id")
     url_dir = _url_dir(request)
     item = request.server.stash.take(id, url_dir)
+    if not item:
+        return None
     return json.dumps(item)
+
+
+def wait_for_preload_to_finish(request, id):
+    """Wait until a preload associated with "id" is sent."""
+    while True:
+        if get_request_timing_and_headers(request, id):
+            break
+        time.sleep(0.1)
+    time.sleep(0.1)