Fix path on Windows test

[email protected], [email protected], [email protected]

Bug: #54903
Change-Id: I132ef3385cdde03ab73df194414a38f9fd9927a9
Cq-Include-Trybots: luci.dart.try:pkg-win-release-try,pkg-win-release-arm64-try,pkg-mac-release-try,pkg-mac-release-arm64-try,pkg-linux-release-try,pkg-linux-release-arm64-try,pkg-linux-debug-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/352240
Reviewed-by: Ben Konyi <[email protected]>
Auto-Submit: Kzrnm <[email protected]>
Commit-Queue: Siva Annamalai <[email protected]>
Reviewed-by: Daco Harkes <[email protected]>
Reviewed-by: Siva Annamalai <[email protected]>

pkg/dartdev/test/commands/analyze_test.dart

@@ -617,13 +617,14 @@ void f() {
           expect(result.exitCode, 3);
           expect(result.stderr, isEmpty);
 
+          final escapedSeparator = path.separator.replaceAll('\\', '\\\\');
           final stdout = result.stdout.trim();
           expect(
               stdout,
               startsWith(
                   '{"version":1,"diagnostics":[{"code":"return_of_invalid_type",'));
           expect(stdout, endsWith('}'));
-          expect(stdout, contains('lib${path.separator}main.dart'));
+          expect(stdout, contains('lib${escapedSeparator}main.dart'));
           expect(stdout, contains('"line":1,"column":16'));
           expect(stdout, contains('"problemMessage":"A value of type '));
         });
@@ -704,9 +705,10 @@ void f() {
           expect(result.exitCode, 3);
           expect(result.stderr, isEmpty);
 
+          final escapedSeparator = path.separator.replaceAll('\\', '\\\\');
           final stdout = result.stdout.trim();
           expect(stdout, contains('|A value of type '));
-          expect(stdout, contains('lib${path.separator}main.dart|1|16|'));
+          expect(stdout, contains('lib${escapedSeparator}main.dart|1|16|'));
         });
       });
       test('short', () {