Improve the heuristics for "pub get" is needed.

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;
 import 'package:pub/src/io.dart';
+import 'package:scheduled_test/scheduled_stream.dart';
 import 'package:scheduled_test/scheduled_test.dart';
 
 import 'descriptor.dart' as d;
 import 'test_pub.dart';
 
 main() {
-  group("requires the user to run pub get first if", () {
-    setUp(() {
-      d.dir(appPath, [
-        d.appPubspec(),
-        d.dir("web", []),
-        d.dir("bin", [
-          d.file("script.dart", "main() => print('hello!');")
-        ])
-      ]).create();
-
-      pubGet();
-
-      // Delay a bit to make sure the modification times are noticeably
-      // different. 1s seems to be the finest granularity that dart:io reports.
-      schedule(() => new Future.delayed(new Duration(seconds: 1)));
+  setUp(() {
+    servePackages((builder) {
+      builder.serve("foo", "1.0.0");
+      builder.serve("foo", "2.0.0");
     });
 
+    d.dir(appPath, [
+      d.appPubspec(),
+      d.dir("web", []),
+      d.dir("bin", [
+        d.file("script.dart", "main() => print('hello!');")
+      ])
+    ]).create();
+
+    pubGet();
+  });
+
+  group("requires the user to run pub get first if", () {
     group("there's no lockfile", () {
       setUp(() {
         schedule(() => deleteEntry(p.join(sandboxDir, "myapp/pubspec.lock")));
       });
 
-      _forEveryCommand(
+      _requiresPubGet(
           'No pubspec.lock file found, please run "pub get" first.');
     });
 
     group("there's no package spec", () {
       setUp(() {
         schedule(() => deleteEntry(p.join(sandboxDir, "myapp/.packages")));
       });
 
-      _forEveryCommand('No .packages file found, please run "pub get" first.');
-    });
-
-    group("the pubspec is newer than the package spec", () {
-      setUp(() {
-        schedule(() => _touch("pubspec.yaml"));
-      });
-
-      _forEveryCommand('The pubspec.yaml file has changed since the .packages '
+      _requiresPubGet('No .packages file found, please run "pub get" first.');
+    });
+
+    group("the pubspec has a new dependency", () {
+      setUp(() {
+        d.dir("foo", [
+          d.libPubspec("foo", "1.0.0")
+        ]).create();
+
+        d.dir(appPath, [
+          d.appPubspec({"foo": {"path": "../foo"}})
+        ]).create();
+
+        // Ensure that the pubspec looks newer than the lockfile.
+        _touch("pubspec.yaml");
+      });
+
+      _requiresPubGet('The pubspec.yaml file has changed since the '
+          'pubspec.lock file was generated, please run "pub get" again.');
+    });
+
+    group("the lockfile has a dependency from the wrong source", () {
+      setUp(() {
+        d.dir(appPath, [
+          d.appPubspec({"foo": "1.0.0"})
+        ]).create();
+
+        pubGet();
+
+        createLockFile(appPath, sandbox: ["foo"]);
+
+        // Ensure that the pubspec looks newer than the lockfile.
+        _touch("pubspec.yaml");
+      });
+
+      _requiresPubGet('The pubspec.yaml file has changed since the '
+          'pubspec.lock file was generated, please run "pub get" again.');
+    });
+
+    group("the lockfile has a dependency from an unknown source", () {
+      setUp(() {
+        d.dir(appPath, [
+          d.appPubspec({"foo": "1.0.0"})
+        ]).create();
+
+        pubGet();
+
+        d.dir(appPath, [
+          d.file("pubspec.lock", yaml({
+            "packages": {
+              "foo": {
+                "description": "foo", 
+                "version": "1.0.0",
+                "source": "sdk"
+              }
+            }
+          }))
+        ]).create();
+
+        // Ensure that the pubspec looks newer than the lockfile.
+        _touch("pubspec.yaml");
+      });
+
+      _requiresPubGet('The pubspec.yaml file has changed since the '
+          'pubspec.lock file was generated, please run "pub get" again.');
+    });
+
+    group("the lockfile has a dependency with the wrong description", () {
+      setUp(() {
+        d.dir("bar", [
+          d.libPubspec("foo", "1.0.0")
+        ]).create();
+
+        d.dir(appPath, [
+          d.appPubspec({"foo": {"path": "../bar"}})
+        ]).create();
+
+        pubGet();
+
+        createLockFile(appPath, sandbox: ["foo"]);
+
+        // Ensure that the pubspec looks newer than the lockfile.
+        _touch("pubspec.yaml");
+      });
+
+      _requiresPubGet('The pubspec.yaml file has changed since the '
+          'pubspec.lock file was generated, please run "pub get" again.');
+    });
+
+    group("the pubspec has an incompatible version of a dependency", () {
+      setUp(() {
+        d.dir(appPath, [
+          d.appPubspec({"foo": "1.0.0"})
+        ]).create();
+
+        pubGet();
+
+        d.dir(appPath, [
+          d.appPubspec({"foo": "2.0.0"})
+        ]).create();
+
+        // Ensure that the pubspec looks newer than the lockfile.
+        _touch("pubspec.yaml");
+      });
+
+      _requiresPubGet('The pubspec.yaml file has changed since the '
+          'pubspec.lock file was generated, please run "pub get" again.');
+    });
+
+    group("the lockfile is pointing to an unavailable package with a newer "
+        "pubspec", () {
+      setUp(() {
+        d.dir(appPath, [
+          d.appPubspec({"foo": "1.0.0"})
+        ]).create();
+
+        pubGet();
+
+        schedule(() => deleteEntry(p.join(sandboxDir, cachePath)));
+
+        // Ensure that the pubspec looks newer than the lockfile.
+        _touch("pubspec.yaml");
+      });
+
+      _requiresPubGet('The pubspec.yaml file has changed since the '
+          'pubspec.lock file was generated, please run "pub get" again.');
+    });
+
+    group("the lockfile is pointing to an unavailable package with an older "
+        ".packages", () {
+      setUp(() {
+        d.dir(appPath, [
+          d.appPubspec({"foo": "1.0.0"})
+        ]).create();
+
+        pubGet();
+
+        schedule(() => deleteEntry(p.join(sandboxDir, cachePath)));
+
+        // Ensure that the lockfile looks newer than the .packages file.
+        _touch("pubspec.lock");
+      });
+
+      _requiresPubGet('The pubspec.lock file has changed since the .packages '
           'file was generated, please run "pub get" again.');
     });
 
-    group("the lockfile is newer than the package spec", () {
-      setUp(() {
-        schedule(() => _touch("pubspec.lock"));
-      });
-
-      _forEveryCommand('The pubspec.lock file has changed since the .packages '
+    group("the lockfile has a package that the .packages file doesn't", () {
+      setUp(() {
+        d.dir("foo", [
+          d.libPubspec("foo", "1.0.0")
+        ]).create();
+
+        d.dir(appPath, [
+          d.appPubspec({"foo": {"path": "../foo"}})
+        ]).create();
+
+        pubGet();
+
+        createPackagesFile(appPath);
+
+        // 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 .packages file has a package with a non-file URI", () {
+      setUp(() {
+        d.dir("foo", [
+          d.libPubspec("foo", "1.0.0")
+        ]).create();
+
+        d.dir(appPath, [
+          d.appPubspec({"foo": {"path": "../foo"}})
+        ]).create();
+
+        pubGet();
+
+        d.dir(appPath, [
+          d.file(".packages", """
+myapp:lib
+foo:http://example.com/
+""")
+        ]).create();
+
+        // 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 .packages file points to the wrong place", () {
+      setUp(() {
+        d.dir("bar", [
+          d.libPubspec("foo", "1.0.0")
+        ]).create();
+
+        d.dir(appPath, [
+          d.appPubspec({"foo": {"path": "../bar"}})
+        ]).create();
+
+        pubGet();
+
+        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("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();
+
+        _touch("pubspec.lock");
+        _touch(".packages");
+      });
+
+      _runsSuccessfully(runDeps: false);
+    });
+
+    group("the pubspec is newer than the lockfile, but they're up-to-date", () {
+      setUp(() {
+        d.dir(appPath, [
+          d.appPubspec({"foo": "1.0.0"})
+        ]).create();
+
+        pubGet();
+
+        _touch("pubspec.yaml");
+      });
+
+      _runsSuccessfully();
+    });
+
+    group("the lockfile is newer than .packages, but they're up-to-date", () {
+      setUp(() {
+        d.dir(appPath, [
+          d.appPubspec({"foo": "1.0.0"})
+        ]).create();
+
+        pubGet();
+
+        _touch("pubspec.lock");
+      });
+
+      _runsSuccessfully();
+    });
   });
 }
 
 /// Runs every command that care about the world being up-to-date, and asserts
 /// that it prints [message] as part of its error.
-void _forEveryCommand(String message) {
+void _requiresPubGet(String message) {
   for (var command in ["build", "serve", "run", "deps"]) {
     integration("for pub $command", () {
       var args = [command];
       if (command == "run") args.add("script");
 
-      var output;
-      var error;
-      if (command == "list-package-dirs") {
-        output = contains(JSON.encode(message));
-      } else {
-        error = contains(message);
-      }
-
       schedulePub(
           args: args,
-          output: output,
-          error: error,
+          error: contains(message),
           exitCode: exit_codes.DATA);
     });
   }
 }
 
+/// Ensures that pub doesn't require "pub get" for the current package.
+///
+/// If [runDeps] is false, `pub deps` isn't included in the test. This is
+/// sometimes not desirable, since it uses slightly stronger checks for pubspec
+/// and lockfile consistency.
+void _runsSuccessfully({bool runDeps: true}) {
+  var commands = ["build", "serve", "run"];
+  if (runDeps) commands.add("deps");
+
+  for (var command in commands) {
+    integration("for pub $command", () {
+      var args = [command];
+      if (command == "run") args.add("bin/script.dart");
+      if (command == "serve") ;
+
+      if (command != "serve") {
+        schedulePub(args: args);
+      } else {
+        var pub = startPub(args: ["serve", "--port=0"]);
+        pub.stdout.expect(consumeThrough(startsWith("Serving myapp web")));
+        pub.kill();
+      }
+
+      schedule(() {
+        // If pub determines that everything is up-to-date, it should set the
+        // mtimes to indicate that.
+        var pubspecModified = new File(p.join(sandboxDir, "myapp/pubspec.yaml"))
+            .lastModifiedSync();
+        var lockFileModified =
+            new File(p.join(sandboxDir, "myapp/pubspec.lock"))
+                .lastModifiedSync();
+        var packagesModified = new File(p.join(sandboxDir, "myapp/.packages"))
+            .lastModifiedSync();
+
+        expect(!pubspecModified.isAfter(lockFileModified), isTrue);
+        expect(!lockFileModified.isAfter(packagesModified), isTrue);
+      }, "testing last-modified times");
+    });
+  }
+}
+
+/// Schedules a non-semantic modification to [path].
 void _touch(String path) {
-  path = p.join(sandboxDir, "myapp", path);
-  writeTextFile(path, readTextFile(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");
 }