Migrate status file entries when migrating files. Yay!

tools/migration/lib/src/migrate_statuses.dart

Index: tools/migration/lib/src/migrate_statuses.dart
diff --git a/tools/migration/lib/src/migrate_statuses.dart b/tools/migration/lib/src/migrate_statuses.dart
new file mode 100644
index 0000000000000000000000000000000000000000..dead6ef88e88527308d65c1b5e747fadb6b81e6c
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+++ b/tools/migration/lib/src/migrate_statuses.dart
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+// 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?
+}
+
+/// 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
+        // 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.
+      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) {
+      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]);
+    }
+  }
+}