Add a test case to verify that the pubspec version is bumped

Author: nex3

test/double_check_test.dart

@@ -0,0 +1,54 @@
+// Copyright 2017 Google Inc. Use of this source code is governed by an
+// MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
+@TestOn('vm')
+
+import 'dart:io';
+import 'dart:convert';
+
+import 'package:crypto/crypto.dart';
+import 'package:test/test.dart';
+import 'package:yaml/yaml.dart';
+
+import '../tool/grind/synchronize.dart' as synchronize;
+
+/// Tests that double-check that everything in the repo looks sensible.
+void main() {
+  group("synchronized file is up-to-date:", () {
+    /// The pattern of a checksum in a generated file.
+    var checksumPattern = RegExp(r"^// Checksum: (.*)$", multiLine: true);
+
+    synchronize.sources.forEach((sourcePath, targetPath) {
+      test(targetPath, () {
+        var target = File(targetPath).readAsStringSync();
+        var actualHash = checksumPattern.firstMatch(target)[1];
+
+        var source = File(sourcePath).readAsBytesSync();
+        var expectedHash = sha1.convert(source).toString();
+        expect(actualHash, equals(expectedHash),
+            reason: "$targetPath is out-of-date.\n"
+                "Run pub run grinder to update it.");
+      });
+    });
+  },
+      // Windows sees different bytes than other OSes, possibly because of
+      // newline normalization issues.
+      testOn: "!windows");
+
+  test("pubspec version matches CHANGELOG version", () {
+    var firstLine = const LineSplitter()
+        .convert(File("CHANGELOG.md").readAsStringSync())
+        .first;
+    expect(firstLine, startsWith("## "));
+    var changelogVersion = firstLine.substring(3);
+
+    var pubspec = loadYaml(File("pubspec.yaml").readAsStringSync(),
+        sourceUrl: "pubspec.yaml") as Map<Object, Object>;
+    expect(pubspec, containsPair("version", isA<String>()));
+    var pubspecVersion = pubspec["version"] as String;
+
+    expect(pubspecVersion,
+        anyOf(equals(changelogVersion), equals("$changelogVersion-dev")));
+  });
+}