Use request uri to establish SSE connection (#736)

* Use request uri to establish SSE connection

Author: grouma

dwds/CHANGELOG.md

@@ -1,5 +1,6 @@
 ## 0.7.5-dev
 
+- The injected client's connection is now based off the request URI.
 - Fix an issue where resuming while paused at the start would cause an error.
 - Expose the `ChromeDebugException` class for error handling purposes.
 

dwds/lib/src/handlers/injected_handler.dart

@@ -30,7 +30,7 @@ Handler Function(Handler) createInjectedHandler(
         int extensionPort}) =>
     (innerHandler) {
       return (Request request) async {
-        if (request.url.path == '$_clientScript.js') {
+        if (request.url.path.endsWith('$_clientScript.js')) {
           var uri = await Isolate.resolvePackageUri(
               Uri.parse('package:$_clientScript.js'));
           var result = await File(uri.toFilePath()).readAsString();
@@ -67,9 +67,16 @@ Handler Function(Handler) createInjectedHandler(
             var mainFunction = bodyLines[extensionIndex + 1]
                 .replaceAll('main()', 'main')
                 .trim();
-            body += _injectedClientJs(configuration, appId, mainFunction,
-                extensionHostname: extensionHostname,
-                extensionPort: extensionPort);
+            var requestedUriBase = '${request.requestedUri.scheme}'
+                '://${request.requestedUri.authority}';
+            body += _injectedClientJs(
+              configuration,
+              appId,
+              mainFunction,
+              requestedUriBase,
+              extensionHostname: extensionHostname,
+              extensionPort: extensionPort,
+            );
             body += bodyLines.sublist(extensionIndex + 2).join('\n');
             // Change the hot restart handler to re-assign
             // `window.$dartRunMain` to the new main, instead of invoking it.
@@ -89,14 +96,20 @@ Handler Function(Handler) createInjectedHandler(
     };
 
 String _injectedClientJs(
-    ReloadConfiguration configuration, String appId, String mainFunction,
-    {String extensionHostname, int extensionPort}) {
+  ReloadConfiguration configuration,
+  String appId,
+  String mainFunction,
+  String requestedUriBase, {
+  String extensionHostname,
+  int extensionPort,
+}) {
   var injectedBody = '// Injected by webdev for build results support.\n'
       'window.\$dartAppId = "$appId";\n'
       'window.\$dartRunMain = $mainFunction;\n'
       'window.\$dartReloadConfiguration = "$configuration";\n'
       'window.\$dartLoader.forceLoadModule("$_clientScript");\n'
       'window.\$dartModuleStrategy = "$loadModule";\n'
+      'window.\$dartUriBase = "$requestedUriBase";\n'
       'window.\$loadModuleConfig = $loadModule;\n';
   if (extensionPort != null && extensionHostname != null) {
     injectedBody += 'window.\$extensionHostname = "$extensionHostname";\n'

dwds/lib/src/injected/client.js

@@ -33,7 +33,7 @@ Future<void> main() {
     // Test apps may already have this set.
     dartAppInstanceId ??= Uuid().v1();
 
-    var client = SseClient(r'/$sseHandler');
+    var client = SseClient(_fixProtocol('$dartUriBase/\$sseHandler'));
     // Ensure the SSE connection is established before proceeding.
     // Note that `onOpen` is a broadcast stream so we must listen for this
     // immediately.
@@ -133,12 +133,31 @@ $stackTrace
   });
 }
 
+/// Returns [url] modified if necessary so that, if the current page is served
+/// over `https`, then the URL is converted to `https`. Localhost is treated
+/// as a special case and not modified.
+String _fixProtocol(String url) {
+  if (window.location.protocol == 'https:' && !url.startsWith('https://')) {
+    // Chrome seems to allow mixed content from localhost.
+    if (url.startsWith('http://localhost')) {
+      return url;
+    } else {
+      return url.replaceFirst('http://', 'https://');
+    }
+  } else {
+    return url;
+  }
+}
+
 @JS(r'$dartAppId')
 external String get dartAppId;
 
 @JS(r'$dartAppInstanceId')
 external String get dartAppInstanceId;
 
+@JS(r'$dartUriBase')
+external String get dartUriBase;
+
 @JS(r'$dartAppInstanceId')
 external set dartAppInstanceId(String id);