Migration: remove changedPaths tracking.

See comments in
https://dart-review.googlesource.com/c/sdk/+/147043/1/pkg/nnbd_migration/lib/migration_cli.dart#484
for why this is unnecessary.

Change-Id: I046835d73eb581aecd8d65b1e3248d07daf34f17
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/147702
Commit-Queue: Paul Berry <paulberry@google.com>
Reviewed-by: Samuel Rawlins <srawlins@google.com>

pkg/analysis_server/lib/src/edit/fix/non_nullable_fix.dart

@@ -80,7 +80,7 @@ class NonNullableFix extends FixCodeTask {
   /// If this occurs, then don't update any code.
   bool _packageIsNNBD = true;
 
-  Future<void> Function([List<String>]) rerunFunction;
+  Future<void> Function() rerunFunction;
 
   /// A list of the URLs corresponding to the included roots.
   List<String> previewUrls;
@@ -257,9 +257,9 @@ environment:
     _packageIsNNBD = false;
   }
 
-  Future<MigrationState> rerun([List<String> changedPaths]) async {
+  Future<MigrationState> rerun() async {
     reset();
-    await rerunFunction(changedPaths);
+    await rerunFunction();
     final state = MigrationState(
         migration, includedRoot, listener, instrumentationListener);
     await state.refresh();

pkg/nnbd_migration/lib/migration_cli.dart

@@ -476,18 +476,7 @@ Use this interactive web view to review, improve, or apply the results.
   bool _isUriError(AnalysisError error) =>
       error.errorCode == CompileTimeErrorCode.URI_DOES_NOT_EXIST;
 
-  Future<void> _rerunFunction([List<String> changedPaths]) async {
-    // Note: we don't support [changedPaths].  The only time it is non-null is
-    // when the tool decides to re-run automatically due to deleting a hint.
-    // That's problematic for two reasons: (1) if the user first makes a change
-    // to some other file (without re-running) and then removes a hint, only the
-    // file affected by the removal will be in changedPaths, so the user will
-    // think that migration has been totally re-run when it hasn't.
-    // (2) removing a hint shouldn't force a re-run anyhow (see
-    // https://github.com/dart-lang/sdk/issues/41795), and once that is fixed
-    // changedPaths will always be null.
-    //
-    // TODO(paulberry): remove changedPaths entirely.
+  Future<void> _rerunFunction() async {
     _dartFixListener.reset();
     _fixCodeProcessor.prepareToRerun();
     await _fixCodeProcessor.runFirstPhase();

pkg/nnbd_migration/lib/src/preview/http_preview_server.dart

@@ -33,7 +33,7 @@ class HttpPreviewServer {
   Future<HttpServer> _serverFuture;
 
   // A function which allows the migration to be rerun, taking changed paths.
-  final Future<MigrationState> Function([List<String>]) rerunFunction;
+  final Future<MigrationState> Function() rerunFunction;
 
   /// Integer for a port to run the preview server on.  If null or zero, allow
   /// [HttpServer.bind] to pick one.

pkg/nnbd_migration/lib/src/preview/preview_site.dart

@@ -60,7 +60,7 @@ class PreviewSite extends Site
   final Map<String, UnitInfo> unitInfoMap = {};
 
   // A function provided by DartFix to rerun the migration.
-  final Future<MigrationState> Function([List<String>]) rerunFunction;
+  final Future<MigrationState> Function() rerunFunction;
 
   final String serviceAuthToken = _makeAuthToken();
 
@@ -257,12 +257,12 @@ class PreviewSite extends Site
     file.writeAsStringSync(newContent);
     unitInfo.diskContent = newContent;
     if (!insertionOnly) {
-      await rerunMigration([path]);
+      await rerunMigration();
     }
   }
 
-  Future<void> rerunMigration([List<String> changedPaths]) async {
-    migrationState = await rerunFunction(changedPaths);
+  Future<void> rerunMigration() async {
+    migrationState = await rerunFunction();
     reset();
   }
 

pkg/nnbd_migration/test/preview/preview_site_test.dart

@@ -35,15 +35,13 @@ class PreviewSiteTest with ResourceProviderMixin, PreviewSiteTestMixin {
   }
 
   void setUp() {
-    reranPaths = null;
     dartfixListener = DartFixListener(null);
     resourceProvider = MemoryResourceProvider();
     final migrationInfo = MigrationInfo({}, {}, null, null);
     state = MigrationState(null, null, dartfixListener, null);
     state.pathMapper = PathMapper(resourceProvider);
     state.migrationInfo = migrationInfo;
-    site = PreviewSite(state, ([paths]) async {
-      reranPaths = paths;
+    site = PreviewSite(state, () async {
       return state;
     });
   }
@@ -160,7 +158,6 @@ void main(List args) {
     expect(file.readAsStringSync(), 'int/*?*/ foo() {}');
     expect(state.hasBeenApplied, false);
     expect(state.needsRerun, true);
-    expect(reranPaths, null);
     expect(unitInfo.content, 'int/*?*/ foo() {}');
   }
 
@@ -181,7 +178,6 @@ mixin PreviewSiteTestMixin {
   PreviewSite site;
   DartFixListener dartfixListener;
   MigrationState state;
-  List<String> reranPaths;
 
   Future<void> performEdit(String path, int offset, String replacement) {
     final pathUri = Uri.file(path).path;
@@ -197,14 +193,12 @@ class PreviewSiteWithEngineTest extends NnbdMigrationTestBase
   @override
   void setUp() {
     super.setUp();
-    reranPaths = null;
     dartfixListener = DartFixListener(null);
     final migrationInfo = MigrationInfo({}, {}, null, null);
     state = MigrationState(null, null, dartfixListener, null);
     state.pathMapper = PathMapper(resourceProvider);
     state.migrationInfo = migrationInfo;
-    site = PreviewSite(state, ([paths]) async {
-      reranPaths = paths;
+    site = PreviewSite(state, () async {
       return state;
     });
   }
@@ -256,6 +250,5 @@ int/*?*/? y = x;
         unitInfo.content.indexOf('= x;') + '= '.length, contains('data flow'));
     expect(state.hasBeenApplied, false);
     expect(state.needsRerun, true);
-    expect(reranPaths, null);
   }
 }