Added functionality to dump relevant status file entries to a single file to make it easier to see …

tools/migration/lib/src/status_file.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 'dart:io';
+
+import 'path.dart';
+
+/// Matches the header that begins a new section, like:

[jcollins, 2017/07/24 18:24:51]

There should probably be a TODO here to merge this code somehow with whatever
code reads these files "for real".

[bkonyi, 2017/07/24 19:16:04]

Do you mean with tools/testing/dart/status_file.dart?

+///
+///     [ $compiler == dart2js && $minified ]
+final _sectionPattern = new RegExp(r"^\[(.+?)\]");
+
+/// Matches an entry that defines the status for a path in the current section,
+/// like:
+///
+///     some/path/to/some_test: Pass || Fail
+final _entryPattern = new RegExp(r"^([^:#]+):(.*)");
+
+/// Matches an issue number in a comment, like:
+///
+///     blah_test: Fail # Issue 1234
+///                       ^^^^
+final _issuePattern = new RegExp(r"[Ii]ssue (\d+)");
+
+/// A parsed status file, which describes how a collection of tests are
+/// expected to behave under various configurations and conditions.
+///
+/// Each status file is made of a series of sections. Each section begins with
+/// a header, followed by a series of entries. A header is enclosed in square
+/// brackets and contains a Boolean expression. That expression is evaluated in
+/// an environment. If it evaluates to true, then the entries after the header
+/// take effect.
+///
+/// Each entry is a glob-like file path followed by a colon and then a
+/// comma-separated list of expectations. The path may point to an individual
+/// file, or a directory, in which case it applies to all files under that path.
+///
+/// Entries may also appear before any section header, in which case they
+/// always apply.
+class StatusFile {
+  final String path;
+  final List<StatusSection> sections = [];
+
+  bool get isEmpty => sections.isEmpty;
+
+  StatusFile(this.path);
+
+  /// Parses the status file at [_path].
+  StatusFile.read(this.path) {
+    var lines = new File(path).readAsLinesSync();
+
+    // The current section whose rules are being parsed.
+    StatusSection section;
+
+    var lineNumber = 0;
+
+    for (var line in lines) {
+      lineNumber++;
+
+      fail(String message, [List<String> errors]) {
+        print('$message in "$_shortPath" line $lineNumber:\n$line');
+
+        if (errors != null) {
+          for (var error in errors) {
+            print("- ${error.replaceAll('\n', '\n  ')}");
+          }
+        }
+        exit(1);
+      }
+
+      // Strip off the comment and whitespace.
+      var source = line;
+      var comment = "";
+      var hashIndex = line.indexOf('#');
+      if (hashIndex >= 0) {
+        source = line.substring(0, hashIndex);
+        comment = line.substring(hashIndex);
+      }
+      source = source.trim();
+      // Ignore empty (or comment-only) lines.
+      if (source.isEmpty) continue;
+
+      // See if we are starting a new section.
+      var match = _sectionPattern.firstMatch(source);
+      if (match != null) {
+        var condition = match[1].trim();
+        section = new StatusSection(condition);
+        sections.add(section);
+        continue;
+      }
+
+      // Otherwise, it should be a new entry under the current section.
+      match = _entryPattern.firstMatch(source);
+      if (match != null) {
+        // If we haven't found a section header yet, create an implicit section
+        // that matches everything.
+        if (section == null) {
+          section = new StatusSection(null);
+          sections.add(section);
+        }
+        if (!comment.isEmpty) {
+          source += " $comment";
+        }
+        section.entries.add(source);
+        continue;
+      }
+
+      fail("Unrecognized input");
+    }
+  }
+
+  /// Gets the path to this status file relative to the Dart repo root.
+  String get _shortPath {
+    var repoRoot = new Path(Platform.script
+            .toFilePath(windows: Platform.operatingSystem == "windows"))
+        .join(new Path("../../../../"));
+    return new Path(_path).relativeTo(repoRoot).toString();
+  }
+
+  String toString() {
+    var buffer = new StringBuffer();
+    for (var section in sections) {
+      buffer.writeln("[${section.condition}]");
+      for (var entry in section.entries) {
+        buffer.writeln(entry.replaceAll("\n", " "));
+      }
+      buffer.writeln();
+    }
+    return buffer.toString();
+  }
+}
+
+/// One section in a status file.
+///
+/// Contains the condition from the header that begins the section, then all of
+/// the entries within the section.
+class StatusSection {
+  /// In that case, the section always applies.
+  final String condition;
+  final List<String> entries = [];
+
+  StatusSection(this.condition);
+
+  String toString() {
+    var buffer = new StringBuffer();
+    buffer.writeln("[$condition]");
+    for (var entry in entries) {
+      buffer.writeln(entry);
+    }
+    buffer.writeln();
+    return buffer.toString();
+  }
+}