Properly handle Windows file: URLs on Node.js (#30098)

This adds logic to the JS implementation of URI to determine whether
the code is running on Windows under Node.js.

Author: nex3

CHANGELOG.md

@@ -27,6 +27,10 @@
     the system level timeout duration, a timeout may occur sooner than specified
     in 'timeout'.
 
+* `dart:core`
+  * The `Uri` class now correctly handles paths while running on Node.js on
+    Windows.
+
 ### Dart VM
 * Support for MIPS has been remvoed.
 

pkg/dev_compiler/tool/input_sdk/patch/core_patch.dart

@@ -602,7 +602,13 @@ class Uri {
 @patch
 class _Uri {
   @patch
-  static bool get _isWindows => false;
+  static bool get _isWindows => _isWindowsCached;
+
+  static final bool _isWindowsCached = JS(
+      'bool',
+      'typeof process != "undefined" && '
+      'Object.prototype.toString.call(process) == "[object process]" && '
+      'process.platform == "win32"');
 
   // Matches a String that _uriEncodes to itself regardless of the kind of
   // component.  This corresponds to [_unreservedTable], i.e. characters that

sdk/lib/_internal/js_runtime/lib/core_patch.dart

@@ -611,7 +611,13 @@ class Uri {
 @patch
 class _Uri {
   @patch
-  static bool get _isWindows => false;
+  static bool get _isWindows => _isWindowsCached;
+
+  static final bool _isWindowsCached = JS(
+      'bool',
+      'typeof process != "undefined" && '
+      'Object.prototype.toString.call(process) == "[object process]" && '
+      'process.platform == "win32"');
 
   // Matches a String that _uriEncodes to itself regardless of the kind of
   // component.  This corresponds to [_unreservedTable], i.e. characters that