[test] Use POST when reporting stdout/stderr in browser tests (#24179)

This helps avoid issues around encoding and limits on URL length.

Followup to #24174

Author: sbc100

test/browser/test_small_js_flags.js.size

@@ -1 +1 @@
-3934
+3936

test/browser_reporting.js

@@ -23,7 +23,11 @@ async function reportResultToServer(result) {
 }
 
 function sendFileToServer(filename, contents) {
-  fetch(`${reportingURL}/?file=${encodeURIComponent(filename)}`, {method: "POST", body: contents});
+  fetch(`${reportingURL}/upload?file=${encodeURIComponent(filename)}`, { method: "POST", body: contents });
+}
+
+function logMessageToServer(filename, message) {
+  fetch(`${reportingURL}/log?file=${filename}`, { method: "POST", body: message })
 }
 
 function maybeReportResultToServer(result) {
@@ -36,15 +40,15 @@ function reportStderrToServer(message) {
   if (typeof ENVIRONMENT_IS_NODE !== 'undefined' && ENVIRONMENT_IS_NODE) {
     err(message);
   } else {
-    fetch(`${reportingURL}?stderr=${encodeURIComponent(message)}`);
+    logMessageToServer('stderr', message);
   }
 }
 
 function reportStdoutToServer(message) {
   if (typeof ENVIRONMENT_IS_NODE !== 'undefined' && ENVIRONMENT_IS_NODE) {
     out(message);
   } else {
-    fetch(`${reportingURL}?stdout=${encodeURIComponent(message)}`);
+    logMessageToServer('stdout', message);
   }
 }
 

test/common.py

@@ -2109,19 +2109,28 @@ def end_headers(self):
     def do_POST(self):
       urlinfo = urlparse(self.path)
       query = parse_qs(urlinfo.query)
-      if query['file']:
-        print('do_POST: got file: %s' % query['file'])
+      content_length = int(self.headers['Content-Length'])
+      post_data = self.rfile.read(content_length)
+      if urlinfo.path == '/log':
+        # Logging reported by reportStdoutToServer / reportStderrToServer.
+        #
+        # To automatically capture stderr/stdout message from browser tests, modify
+        # `captureStdoutStderr` in `test/browser_reporting.js`.
+        filename = query['file'][0]
+        print(f"[client {filename}: '{post_data.decode()}']")
+        self.send_response(200)
+        self.end_headers()
+      elif urlinfo.path == '/upload':
         filename = query['file'][0]
-        contentLength = int(self.headers['Content-Length'])
-        create_file(filename, self.rfile.read(contentLength), binary=True)
+        print(f'do_POST: got file: {filename}')
+        create_file(filename, post_data, binary=True)
         self.send_response(200)
         self.end_headers()
       else:
         print(f'do_POST: unexpected POST: {urlinfo.query}')
 
     def do_GET(self):
       info = urlparse(self.path)
-      query = parse_qs(info.query)
       if info.path == '/run_harness':
         if DEBUG:
           print('[server startup]')
@@ -2162,16 +2171,6 @@ def do_GET(self):
         self.end_headers()
         self.wfile.write(b'OK')
 
-      elif info.path == '/' and 'stdout' in query or 'stderr' in query:
-        # Logging reported by reportStdoutToServer / reportStderrToServer.
-        #
-        # To automatically capture stderr/stdout message from browser tests, modify
-        # `captureStdoutStderr` in `test/browser_reporting.js`.
-        for key, value in query.items():
-          print(f"[client {key}: '{value[0]}']")
-        self.send_response(200)
-        self.send_header('Content-type', 'text/html')
-        self.end_headers()
       elif info.path == '/check':
         self.send_response(200)
         self.send_header('Content-type', 'text/html')

test/fetch/test_fetch_post.c

@@ -57,7 +57,7 @@ int main() {
   attr.onerror = onError;
   attr.requestData = "Hello, world!";
   attr.requestDataSize = strlen(attr.requestData);
-  emscripten_fetch(&attr, "?file=newfile.txt");
+  emscripten_fetch(&attr, "upload?file=newfile.txt");
 
   // This return code should be ignored
   return 99;