[CI] test_download: check whether self-update downloaded from the exp…

…ected url

CI/test_download.py

@@ -16,6 +16,7 @@
 import urllib.parse
 import urllib.request
 from concurrent.futures import Future, ThreadPoolExecutor
+from contextlib import contextmanager
 from io import BytesIO
 from pathlib import Path
 from tempfile import TemporaryDirectory
@@ -84,6 +85,9 @@ def get_version(x, **kwargs):
             return result
         return result.removeprefix("git-cinnabar ")
 
+    def first(list):
+        return checked_call(next, iter(list))
+
     executor = ThreadPoolExecutor(max_workers=1)
 
     def get_pkg():
@@ -236,16 +240,21 @@ def get_pkg():
         if last_tag in urls:
             shutil.copytree(cwd / v, update_dir, symlinks=True, dirs_exist_ok=True)
             git_cinnabar_v = update_dir / git_cinnabar.name
-            status += assert_eq(
-                Result(
-                    check_output,
-                    [git_cinnabar_v, "self-update"],
-                    stderr=subprocess.STDOUT,
-                ),
-                "WARNING Did not find an update to install."
-                if v in (head, head_version)
-                else f"Installing update from {urls[last_tag]}",
-            )
+            with proxy.capture_log() as log:
+                status += assert_eq(
+                    Result(
+                        check_output,
+                        [git_cinnabar_v, "self-update"],
+                        stderr=subprocess.STDOUT,
+                    ),
+                    "WARNING Did not find an update to install."
+                    if v in (head, head_version)
+                    else f"Installing update from {urls[last_tag]}",
+                )
+            if t == head:
+                status += assert_eq(log, [])
+            else:
+                status += assert_eq(Result(first, log), urls[last_tag])
             status += assert_eq(
                 Result(get_version, [git_cinnabar_v, "--version"]),
                 full_versions[head] if t == head else full_versions[last_tag],
@@ -254,16 +263,21 @@ def get_pkg():
 
         if head_branch in urls:
             shutil.copytree(cwd / v, update_dir, symlinks=True, dirs_exist_ok=True)
-            status += assert_eq(
-                Result(
-                    check_output,
-                    [git_cinnabar_v, "self-update", "--branch", head_branch],
-                    stderr=subprocess.STDOUT,
-                ),
-                "WARNING Did not find an update to install."
-                if v in (head, head_version)
-                else f"Installing update from {urls[head_branch]}",
-            )
+            with proxy.capture_log() as log:
+                status += assert_eq(
+                    Result(
+                        check_output,
+                        [git_cinnabar_v, "self-update", "--branch", head_branch],
+                        stderr=subprocess.STDOUT,
+                    ),
+                    "WARNING Did not find an update to install."
+                    if v in (head, head_version)
+                    else f"Installing update from {urls[head_branch]}",
+                )
+            if t == head:
+                status += assert_eq(log, [])
+            else:
+                status += assert_eq(Result(first, log), urls[head_branch])
             status += assert_eq(
                 Result(get_version, [git_cinnabar_v, "--version"]),
                 full_versions[head],
@@ -438,6 +452,7 @@ def checked_call(f, *args, **kwargs):
 class ProxyServer(http.server.ThreadingHTTPServer):
     def __init__(self):
         super().__init__(("localhost", 0), ProxyHTTPRequestHandler)
+        self.log = None
         self.mappings = {}
         self.url = f"http://localhost:{self.server_port}"
         self.thread = Thread(target=self.serve_forever)
@@ -452,13 +467,34 @@ def __init__(self):
             this_script.with_name("selfsigned.key"),
         )
 
-    def map(self, url, content):
-        u = urllib.parse.urlparse(url)
+    @contextmanager
+    def capture_log(self):
+        assert self.log is None
+        self.log = []
+        yield self.log
+        self.log = None
+
+    def log_url(self, url_elements):
+        if self.log is not None:
+            host, port, path = url_elements
+            url = f"https://{host}"
+            if port != 443:
+                url += f":{port}"
+            url += path
+            self.log.append(url)
+
+    @staticmethod
+    def urlsplit(url):
+        u = urllib.parse.urlsplit(url)
         assert u.scheme == "https"
         path = u.path
         if u.query:
             path = f"{path}?{u.query}"
-        self.mappings.setdefault((u.hostname, u.port or 443), {})[path] = content
+        return (u.hostname, u.port or 443, path)
+
+    def map(self, url, content):
+        host, port, path = self.urlsplit(url)
+        self.mappings.setdefault((host, port), {})[path] = content
 
 
 class ProxyHTTPRequestHandler(http.server.BaseHTTPRequestHandler):
@@ -468,15 +504,17 @@ def do_CONNECT(self):
         self.send_response_only(200)
         self.end_headers()
 
-        mappings = self.server.mappings.get((host, port))
-        if mappings:
+        mappings = self.server.mappings.get((host, port), {})
+        if mappings or self.server.log is not None:
             self.handle_locally(mappings, host, port)
         else:
             self.pass_through(host, port)
 
     def handle_locally(self, mappings, host, port):
         with self.server.context.wrap_socket(self.connection, server_side=True) as sock:
-            HTTPRequestHandler(sock, self.client_address, (mappings, host, port))
+            HTTPRequestHandler(
+                sock, self.client_address, (self.server, mappings, host, port)
+            )
 
     def pass_through(self, host, port):
         with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
@@ -501,8 +539,9 @@ def relay(src, dest):
 
 class HTTPRequestHandler(http.server.BaseHTTPRequestHandler):
     def do_GET(self):
-        mappings, host, port = self.server
+        server, mappings, host, port = self.server
         content = mappings.get(self.path)
+        server.log_url((host, port, self.path))
         if content:
             self.send_content(content)
         else: