Add a Pub test that runs against the real Dart SDK.

utils/tests/pub/test_pub.dart

Index: utils/tests/pub/test_pub.dart
diff --git a/utils/tests/pub/test_pub.dart b/utils/tests/pub/test_pub.dart
index 2fcac50880bf6d502406384ce2033cfca24296d1..7a79f4b39c644438d57adf3a9ebf07d863239563 100644
--- a/utils/tests/pub/test_pub.dart
+++ b/utils/tests/pub/test_pub.dart
@@ -445,6 +445,12 @@ final String appPath = "myapp";
 final String packagesPath = "$appPath/packages";
 
 /**
+ * The path to the build directory of the Dart repository. This is only set if
+ * [ensureBuild] has been run for this test.
+ */
+String _buildPath;
+
+/**
  * The type for callbacks that will be fired during [runPub]. Takes the sandbox
  * directory as a parameter.
  */
@@ -509,12 +515,18 @@ String get testDirectory {
   return new File(dir.toNativePath()).fullPathSync();
 }
 
+/// Whether the tests are running on a build bot.
+bool get onBuildBot => Platform.environment.containsKey('BUILDBOT_BUILDERNAME');
+
 /**
  * Schedules a call to the Pub command-line utility. Runs Pub with [args] and
  * validates that its results match [output], [error], and [exitCode].
+ *
+ * If [realSdk] is true, runs Pub against the real Dart SDK. [ensureBuild] must
+ * be called before this method if [realSdk] is true.
  */
 void schedulePub({List<String> args, Pattern output, Pattern error,
-    int exitCode: 0}) {
+    int exitCode: 0, bool realSdk: false}) {
   _schedule((sandboxDir) {
     String pathInSandbox(path) => join(getFullPath(sandboxDir), path);
 
@@ -538,7 +550,14 @@ void schedulePub({List<String> args, Pattern output, Pattern error,
 
       var environment = new Map.from(Platform.environment);
       environment['PUB_CACHE'] = pathInSandbox(cachePath);
-      environment['DART_SDK'] = pathInSandbox(sdkPath);
+      if (realSdk) {
+        if (_buildPath == null) {
+          throw "Test error: expected a Dart build directory to exist.";
+        }
+        environment['DART_SDK'] = join(_buildPath, "dart-sdk");
+      } else {
+        environment['DART_SDK'] = pathInSandbox(sdkPath);
+      }
 
       return runProcess(dartBin, dartArgs, workingDir: pathInSandbox(appPath),
           environment: environment);
@@ -589,8 +608,7 @@ void runPub({List<String> args, Pattern output, Pattern error,
 void ensureGit() {
   _schedule((_) {
     return isGitInstalled.transform((installed) {
-      if (!installed &&
-          !Platform.environment.containsKey('BUILDBOT_BUILDERNAME')) {
+      if (!installed && !onBuildBot) {
         _abortScheduled = true;
       }
       return null;
@@ -598,6 +616,53 @@ void ensureGit() {
   });
 }
 
+/// Skips the current test if the Dart repository's build step has not been run.
+/// If we're running on a build bot, this will not skip the test.
+///
+/// This ensures that users don't need to have built Dart themselves to run the
+/// test, but that the test will always run on the build bot.
+void ensureBuild() {
+  _schedule((_) {
+    return _findBuildDirectory().transform((dir) {
+      if (dir == null && !onBuildBot) {
+        _abortScheduled = true;
+      }
+    });
+  });
+}
+
+/// All possible names for the output directory of the Dart build.
+final List<String> _buildNames = [
+  'ReleaseIA32', 'DebugIA32', 'ReleaseX64', 'DebugX64', 'ReleaseSIMARM',
+  'DebugSIMARM', 'ReleaseARM', 'DebugARM'
+];
+
+/// All possible names for the parent directory of the Dart build.
+final Map<String, String> _buildParentNames = {
+  'mac': 'xcodebuild', 'linux': 'out', 'windows': 'build'
+};
+
+/// Returns the path to the output directory of the Dart build, or null if none
+/// is found. This also sets [_buildPath] if a build directory is found.
+Future<String> _findBuildDirectory() {
+  if (_buildPath != null) return new Future.immediate(_buildPath);
+
+  var buildDirectories = flatten(_buildNames.map((name) {
+    var parent = _buildParentNames[Platform.operatingSystem];
+    return join(testDirectory, '../../..', parent, name);
+  }));
+
+  return Futures.wait(buildDirectories.map(dirExists)).transform((found) {
+    for (var i = 0; i < found.length; i++) {
+      if (found[i]) {
+        _buildPath = buildDirectories[i];
+        return _buildPath;
+      }
+    }
+    return null;
+  });
+}
+
 Future<Directory> _setUpSandbox() {
   return createTempDir();
 }