[analysis_server] Update some more tests to handle EOL normalization

This sets `useLineEndingsForPlatform=true` for basic completion tests that now pass, but leave it set to `false` in `AbstractCompletionDriverTest` for now because there are a large number of failures in other tests that use that base class due to hard-coded offsets.

It also updates the format tests to support this (plus extracts some helpers to reduce the duplication).

Change-Id: Id2a0323b4605761d05e30bee89f7dccebb1f48c4
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/451020
Reviewed-by: Brian Wilkerson <[email protected]>
Commit-Queue: Brian Wilkerson <[email protected]>
Reviewed-by: Samuel Rawlins <[email protected]>

Author: DanTup

pkg/analysis_server/test/client/completion_driver_test.dart

@@ -2,6 +2,7 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+import 'package:analyzer/src/test_utilities/platform.dart';
 import 'package:analyzer_plugin/protocol/protocol_common.dart';
 import 'package:meta/meta.dart';
 import 'package:test/test.dart';
@@ -74,11 +75,11 @@ abstract class AbstractCompletionDriverTest
 
   @override
   @protected
-  Future<List<CompletionSuggestion>> addTestFile(
-    String content, {
-    int? offset,
-  }) async {
-    driver.addTestFile(content, offset: offset);
+  Future<List<CompletionSuggestion>> addTestFile(String content) async {
+    if (useLineEndingsForPlatform) {
+      content = normalizeNewlinesForPlatform(content);
+    }
+    driver.addTestFile(content);
 
     // Wait after adding the test file, this might affect diagnostics.
     await pumpEventQueue(times: 1000);

pkg/analysis_server/test/client/impl/completion_driver.dart

@@ -36,15 +36,9 @@ class CompletionDriver with ExpectMixin {
     server.serverChannel.notifications.listen(processNotification);
   }
 
-  void addTestFile(String content, {int? offset}) {
+  void addTestFile(String content) {
     var code = TestCode.parse(content);
-
-    if (offset != null) {
-      expect(code.positions, isEmpty, reason: 'cannot supply offset and ^');
-      completionOffset = offset;
-    } else {
-      completionOffset = code.position.offset;
-    }
+    completionOffset = code.position.offset;
 
     server.newFile(server.testFilePath, code.code);
   }

pkg/analysis_server/test/completion_test_support.dart

@@ -123,6 +123,16 @@ abstract class CompletionTestCase extends AbstractCompletionDomainTest {
       await super.tearDown();
     }
   }
+
+  @override
+  Future<void> setUp() async {
+    // TODO(dantup): All tests that use this base class support normalization
+    //  however the base class of this (`AbstractCompletionDomainTest`) has a
+    //  lot of other tests classes that do not currently.
+    useLineEndingsForPlatform = true;
+
+    await super.setUp();
+  }
 }
 
 /// A specification of the completion results expected at a given location.