ENH: Add URL verification to s4ext file check

The URL is requested from the server and verified that it returns with OK status (200).

Also added the option to specify filenames with wildcards. For example, this allows easily running URL checks on all files locally:

    python.exe check_description_files.py --check-urls *.s4ext

scripts/check_description_files.py

@@ -70,6 +70,40 @@ def check_scmurl_syntax(extension_name, metadata):
             extension_name, check_name,
             "scmurl scheme is '%s' but it should by any of %s" % (scheme, supported_schemes))
 
+@require_metadata_key("homepage")
+@require_metadata_key("iconurl")
+@require_metadata_key("screenshoturls")
+def check_urls(extension_name, metadata):
+    check_name = "check_urls"
+
+    urls = []
+    urls.append(['homepage', metadata["homepage"]])
+    urls.append(['iconurl', metadata["iconurl"]])
+    if metadata["screenshoturls"] is not None:
+        screenshoturls = metadata["screenshoturls"].split(' ')
+    else:
+        screenshoturls = [""]
+    for screenshoturl in screenshoturls:
+        urls.append(['screenshoturl', screenshoturl])
+
+    supported_schemes = ["http", "https"]
+    import requests
+    for name, url in urls:
+        if not url:
+            raise ExtensionCheckError(
+                extension_name, check_name,
+                f"{name} URL check failed: empty URL")
+        scheme = urlparse.urlsplit(url).scheme
+        if scheme not in supported_schemes:
+            raise ExtensionCheckError(
+                extension_name, check_name,
+                f"{name} URL check failed for {url}: scheme is {scheme} but it should by any of {supported_schemes}")
+        try:
+            request = requests.get(url)
+        except Exception as e:
+            raise ExtensionCheckError(extension_name, check_name, f"{name} URL check failed for {url} ({e})")
+        if request.status_code != 200:
+            raise ExtensionCheckError(extension_name, check_name, f"{name} URL check failed for {url} (status: {request.status_code})")
 
 @require_metadata_key("scmurl")
 @require_metadata_key("scm")
@@ -134,24 +168,42 @@ def main():
     parser.add_argument(
         "--check-git-repository-name", action="store_true",
         help="Check extension git repository name. Disabled by default.")
-    parser.add_argument("-d", "--check-dependencies", help="Check all extension dsecription files in the provided folder.")
-    parser.add_argument("/path/to/description.s4ext", nargs='*')
+    parser.add_argument(
+        "--check-urls", action="store_true",
+        help="Check extension website and images urls. Disabled by default.")
+    parser.add_argument("-d", "--check-dependencies",
+        help="Check dependencies between all extension description files in the specified folder.")
+    parser.add_argument("/path/to/description.s4ext", nargs='*',
+        help="Extension description file(s) to check. Wildcards are accepted.")
     args = parser.parse_args()
 
     checks = []
 
     if args.check_git_repository_name:
         checks.append(check_git_repository_name)
+    if args.check_urls:
+        checks.append(check_urls)
 
     if not checks:
         checks = [
             check_scmurl_syntax,
+            check_urls,
         ]
 
     total_failure_count = 0
 
     file_paths = getattr(args, "/path/to/description.s4ext")
+    # Resolve wildcards to filenames
+    resolved_file_paths = []
+    import glob
     for file_path in file_paths:
+        if '*' in file_path:
+            paths = glob.glob(file_path)
+            resolved_file_paths.extend(paths)
+        else:
+            resolved_file_paths.extend(file_path)
+    # Iterate through all the files
+    for file_path in resolved_file_paths:
         extension_name = os.path.splitext(os.path.basename(file_path))[0]
 
         failures = []