Use substr instead of endswith

Author: edwin0cheng

editors/code/src/test/utils/diagnotics/rust.test.ts

@@ -229,8 +229,8 @@ describe('mapRustDiagnosticToVsCode', () => {
         // The file url should be normal file
         // Ignore the first part because it depends on vs workspace location
         assert.strictEqual(
-            true,
-            location.uri.toString().endsWith('src/main.rs'),
+            location.uri.path.substr(-'src/main.rs'.length),
+            'src/main.rs',
         );
     });
 });