Show detailed report on upgrade.

sdk/lib/_internal/pub/lib/src/command/upgrade.dart

Index: sdk/lib/_internal/pub/lib/src/command/upgrade.dart
diff --git a/sdk/lib/_internal/pub/lib/src/command/upgrade.dart b/sdk/lib/_internal/pub/lib/src/command/upgrade.dart
index 306e027cfdf9b30fac4d4177048871aa2b07817a..08fa1e88a1f4f5723c4c41a144ceec9601bbf688 100644
--- a/sdk/lib/_internal/pub/lib/src/command/upgrade.dart
+++ b/sdk/lib/_internal/pub/lib/src/command/upgrade.dart
@@ -26,15 +26,17 @@ class UpgradeCommand extends PubCommand {
   }
 
   Future onRun() {
-    var future;
-    if (commandOptions.rest.isEmpty) {
-      future = entrypoint.upgradeAllDependencies();
-    } else {
-      future = entrypoint.upgradeDependencies(commandOptions.rest);
-    }
-
-    return future.then((_) {
-      log.message("Dependencies upgraded!");
+    var upgradeAll = commandOptions.rest.isEmpty;
+    return entrypoint.getDependencies(useLatest: commandOptions.rest,
+        upgradeAll: upgradeAll).then((numChanged) {
+      if (numChanged == 0) {
+        log.message("No dependencies changed.");
+      } else if (numChanged == 1) {
+        log.message("Changed $numChanged dependency!");
+      } else {
+        log.message("Changed $numChanged dependencies!");

[nweiz, 2013/12/11 06:48:32]

I don't know how clear the notion of "changing a dependency" will be to users. I
assume it's because sometimes a dependency is downgraded or switched to a
different source instead of upgraded, but it would be nice if we could provide
positive-sounding output when only upgrades happened. Maybe if [getDependencies]
returned both numUpgraded and numChanged?

[Bob Nystrom, 2013/12/11 22:36:59]

Yup, also the common cases of adding a new dependency or removing one.
I added a TODO. We can improve this, but at some point we're just gilding the
lily. I think the most important point (and the one users have asked for) is
that we tell them if nothing changed. This covers that. The report itself covers
the other stuff.

+      }
+
       if (isOffline) {
         log.warning("Warning: Upgrading when offline may not update you to the "
                     "latest versions of your dependencies.");