Improve the detection lockfile freshness.

test/must_pub_get_test.dart

 // Copyright (c) 2015, 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:async';
 import 'dart:convert';
 import 'dart:io';
 
 import 'package:path/path.dart' as p;
 import 'package:pub/src/exit_codes.dart' as exit_codes;
@@ skipping 247 matching lines @@
 
         createPackagesFile(appPath, sandbox: ["foo"]);
 
         // Ensure that the pubspec looks newer than the lockfile.
         _touch("pubspec.lock");
       });
 
       _requiresPubGet('The pubspec.lock file has changed since the .packages '
           'file was generated, please run "pub get" again.');
     });
+
+    group("the lock file's SDK constraint doesn't match the current SDK", () {
+      setUp(() {
+        // Avoid using a path dependency because it triggers the full validation
+        // logic. We want to be sure SDK-validation works without that logic.
+        servePackages((builder) {
+          builder.serve("foo", "3.0.0", pubspec: {
+            "environment": {"sdk": ">=1.0.0 <2.0.0"}
+          });
+        });
+
+        d.dir(appPath, [
+          d.appPubspec({"foo": "3.0.0"})
+        ]).create();
+
+        pubGet(environment: {"_PUB_TEST_SDK_VERSION": "1.2.3+4"});
+      });
+
+      _requiresPubGet("Dart 0.1.2+3 is incompatible with your dependencies' "
+          "SDK constraints. Please run \"pub get\" again.");
+    });
+
+    group("a path dependency's dependency doesn't match the lockfile", () {
+      setUp(() {
+        d.dir("bar", [
+          d.libPubspec("bar", "1.0.0", deps: {"foo": "1.0.0"})
+        ]).create();
+
+        d.dir(appPath, [
+          d.appPubspec({"foo": {"path": "../foo"}})
+        ]);
+
+        pubGet();
+
+        // Update foo's pubspec without touching the app's.
+        d.dir("bar", [
+          d.libPubspec("bar", "1.0.0", deps: {"foo": "2.0.0"})
+        ]).create();
+      });
+    });
   });
 
   group("doesn't require the user to run pub get first if", () {
     group("the pubspec is older than the lockfile which is older than the "
         "packages file, even if the contents are wrong", () {
       setUp(() {
         d.dir(appPath, [
           d.appPubspec({"foo": "1.0.0"})
         ]).create();
 
@@ skipping 95 matching lines @@
 void _touch(String path) {
   schedule(() async {
     // Delay a bit to make sure the modification times are noticeably different.
     // 1s seems to be the finest granularity that dart:io reports.
     await new Future.delayed(new Duration(seconds: 1));
 
     path = p.join(sandboxDir, "myapp", path);
     touch(path);
   }, "touching $path");
 }