Migrate status file entries when migrating files. Yay!

tools/migration/lib/src/migrate_statuses.dart

+// Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
+// 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:path/path.dart' as p;
+
+import 'editable_status_file.dart';
+import 'fork.dart';
+import 'io.dart';
+import 'test_directories.dart';
+
+/// Migrates the status file entries that match [files].
+void migrateStatusEntries(List<Fork> files) {
+  var entriesToMove = new EntrySet();
+
+  _collectEntries(files, entriesToMove, isOne: true);
+  _collectEntries(files, entriesToMove, isOne: false);
+
+  for (var statusFile in entriesToMove.statusFiles) {
+    var sections = entriesToMove.sections(statusFile);
+    _addEntries(statusFile, sections);
+  }
+
+  // TODO(rnystrom): Should this log any output?

[bkonyi, 2017/07/27 22:02:00]

I'm not sure if it would be worth still outputting a file like we were before,
but it might make it easier to understand what status file entries were migrated
and help track down entries that cause different failures in Dart 2.0 more
quickly instead of searching for the test name in all the status files.
Thoughts?

[Bob Nystrom, 2017/07/27 22:58:19]

You'll see the actual diff of the changes when you go to commit it in Git, so I
figured that was probably as clear as you can get.

+}
+
+/// Tracks a set of entries to add to a set of Dart 2.0 status files.
+class EntrySet {
+  /// Keys are the names of the Dart 2.0 status file that will receive the
+  /// entries. The value for each key is a map of section headers to the list
+  /// of entries to add under that section.
+  final Map<String, Map<String, List<String>>> _files = {};
+
+  Iterable<String> get statusFiles => _files.keys;
+
+  void add(String fromDir, String header, String entry) {
+    var toDir = toTwoDirectory(fromDir);
+    var sections = _files.putIfAbsent(p.join(toDir, "$toDir.status"), () => {});
+    var entries = sections.putIfAbsent(header, () => []);
+    entries.add(entry);
+  }
+
+  Map<String, List<String>> sections(String file) => _files[file];
+}
+
+/// Removes entries from the 1.0 and strong status files that correspond to
+/// the list of [files] being migrated.
+///
+/// Adds moved entries to [entriesToMove].
+void _collectEntries(List<Fork> files, EntrySet entriesToMove, {bool isOne}) {
+  // Map the files to the way they will appear in the status file.
+  var filePaths = files
+      .map((fork) => p.withoutExtension(isOne ? fork.onePath : fork.strongPath))
+      .toList();
+
+  for (var fromDir in isOne ? oneRootDirs : strongRootDirs) {
+    for (var path in listFiles(fromDir, extension: ".status")) {
+      var editable = new EditableStatusFile(path);
+
+      var deleteLines = <int>[];
+      for (var section in editable.statusFile.sections) {
+        // TODO(rnystrom): For now, we don't support entries in the initial

[bkonyi, 2017/07/27 22:02:01]

I haven't run into this case yet myself, and I think it's unlikely that someone
has made a status file entry that doesn't have a condition associated with it.

[Bob Nystrom, 2017/07/27 22:58:19]

There are definitely ones like that, but not too many, I don't think.

+        // implicit section at the top of the file. Do we need to?
+        if (section.condition == null) continue;
+
+        for (var entry in section.entries) {
+          var entryPath = p.join(fromDir, entry.path);
+
+          for (var filePath in filePaths) {
+            // We only support entries that precisely match the file being
+            // migrated, or a multitest within that. In both cases, the entry
+            // path will begin with the full path of the file. We don't migrate
+            // directory or glob patterns because those may also match other
+            // files that have not been migrated yet.
+            // TODO(rnystrom): It would be good to detect when a glob matches
+            // a migrated file and let the user know that they may need to
+            // manually handle it.
+            if (!entryPath.startsWith(filePath)) continue;
+
+            // Remove it from this status file.
+            deleteLines.add(entry.lineNumber - 1);
+
+            // And add it to the 2.0 one.
+            entriesToMove.add(fromDir, editable.lineAt(section.lineNumber),
+                editable.lineAt(entry.lineNumber));
+          }
+        }
+      }
+
+      // TODO(rnystrom): If all of the entries are deleted from a section, it
+      // would be nice to delete the section header too.

[bkonyi, 2017/07/27 22:02:00]

Agreed.

[Bob Nystrom, 2017/07/27 22:58:19]

Acknowledged.

+      editable.delete(deleteLines);
+    }
+  }
+}
+
+/// Adds all of [entries] to the status file at [path].
+///
+/// If the status file already has a section that matches a header in [entries],
+/// then adds those entries to the end of that section. Otherwise, appends a
+/// new section to the end of the file.
+void _addEntries(String path, Map<String, List<String>> entries) {
+  var editable = new EditableStatusFile(p.join(testRoot, path));
+
+  for (var header in entries.keys) {
+    var found = false;
+
+    // Look for an existing section with the same header to add it to.
+    for (var section in editable.statusFile.sections) {
+      // TODO(bob): Handle adding stuff to the empty section.

[bkonyi, 2017/07/27 22:02:01]

// TODO(rnystrom): ...

[Bob Nystrom, 2017/07/27 22:58:19]

Oops, don't need that anymore. Deleted.

+      if (section.lineNumber == -1) continue;
+
+      if (header == editable.lineAt(section.lineNumber)) {
+        var line = section.lineNumber;
+        // Add after existing entries, if there are any.
+        if (section.entries.isNotEmpty) {
+          line = section.entries.last.lineNumber;
+        }
+
+        editable.insert(line, entries[header]);
+        found = true;
+        break;
+      }
+    }
+
+    if (!found) {
+      // This section doesn't exist in the status file, so add it.
+      editable.append(header, entries[header]);
+    }
+  }
+}