Use ephemeral ports for serving stuff during the pub tests.

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 067343330b8ecc5aa0269a8636a0ca35673f1067..683b6857093ee26a6c6715be0c1fa7c40768e925 100644
--- a/utils/tests/pub/test_pub.dart
+++ b/utils/tests/pub/test_pub.dart
@@ -60,20 +60,35 @@ TarFileDescriptor tar(Pattern name, [List<Descriptor> contents]) =>
  */
 var _server;
 
+/** The cached value for [_portCompleter]. */
+Completer<int> _portCompleterCache;
+
+/** The completer for [port]. */
+Completer<int> get _portCompleter() {

[Bob Nystrom, 2012/08/23 21:49:13]

New getter syntax. :)

[nweiz, 2012/08/23 22:25:49]

Done.

+  if (_portCompleterCache != null) return _portCompleterCache;
+  _portCompleterCache = new Completer<int>();
+  _scheduleCleanup((_) {
+    _portCompleterCache = null;
+  });
+  return _portCompleterCache;
+}
+
+/**
+ * A future that will complete to the port used for the current server.
+ */
+Future<int> get port() => _portCompleter.future;
+
 /**
  * Creates an HTTP server to serve [contents] as static files. This server will
  * exist only for the duration of the pub run.
  *
  * Subsequent calls to [serve] will replace the previous server.
  */
-void serve(String host, int port, [List<Descriptor> contents]) {
+void serve([List<Descriptor> contents]) {
   var baseDir = dir("serve-dir", contents);
-  if (host == 'localhost') {
-    host = '127.0.0.1';
-  }
 
   _schedule((_) {
-    _closeServer().transform((_) {
+    _closeServer().transform((resolvedPort) {
       _server = new HttpServer();
       _server.defaultRequestHandler = (request, response) {
         var path = request.uri.replaceFirst("/", "").split("/");
@@ -103,7 +118,8 @@ void serve(String host, int port, [List<Descriptor> contents]) {
           response.outputStream.close();
         });
       };
-      _server.listen(host, port);
+      _server.listen("127.0.0.1", 0);
+      _portCompleter.complete(_server.port);
       _scheduleCleanup((_) => _closeServer());
       return null;
     });
@@ -118,6 +134,7 @@ Future _closeServer() {
   if (_server == null) return new Future.immediate(null);
   _server.close();
   _server = null;
+  _portCompleterCache = null;
   // TODO(nweiz): Remove this once issue 4155 is fixed. Pumping the event loop
   // *seems* to be enough to ensure that the server is actually closed, but I'm
   // putting this at 10ms to be safe.
@@ -125,37 +142,70 @@ Future _closeServer() {
 }
 
 /**
+ * The [DirectoryDescriptor] describing the server layout of packages that are
+ * being served via [servePackages]. This is `null` if [servePackages] has not
+ * yet been called for this test.
+ */
+DirectoryDescriptor _servedPackageDir;
+
+/**
+ * A map from package names to version numbers to YAML-serialized pubspecs for
+ * those packagesk. This represents the packages currently being served by

[Bob Nystrom, 2012/08/23 21:49:13]

"packagesk" -> "packages".

[nweiz, 2012/08/23 22:25:49]

Done.

+ * [servePackages], and is `null` if [servePackages] has not yet been called for
+ * this test.
+ */
+Map<String, Map<String, String>> _servedPackages;
+
+/**
  * Creates an HTTP server that replicates the structure of pub.dartlang.org.
  * [pubspecs] is a list of unserialized pubspecs representing the packages to
  * serve.
+ *
+ * Subsequent calls to [servePackages] will add to the set of packages that are
+ * being served. Previous packages will continue to be served.
  */
-void servePackages(String host, int port, List<Map> pubspecs) {
-  var packages = <String, Map<String, String>>{};
-  for (var spec in pubspecs) {
-    var name = spec['name'];
-    var version = spec['version'];
-    packages.putIfAbsent(name, () => <String, String>{})[version] = yaml(spec);
+void servePackages(List<Map> pubspecs) {
+  if (_servedPackages == null || _servedPackageDir) {
+    _servedPackages = <String, Map<String, String>>{};
+    _servedPackageDir = dir('packages', []);
+    serve([_servedPackageDir]);
+
+    _scheduleCleanup((_) {
+      _servedPackages = null;
+      _servedPackageDir = null;
+    });
   }
 
-  serve(host, port, [
-    dir('packages', flatten(packages.getKeys().map((name) {
-      return [
-        file('$name.json',
-          JSON.stringify({'versions': packages[name].getKeys()})),
-        dir(name, [
-          dir('versions', flatten(packages[name].getKeys().map((version) {
-            return [
-              file('$version.yaml', packages[name][version]),
-              tar('$version.tar.gz', [
-                file('pubspec.yaml', packages[name][version]),
-                file('$name.dart', 'main() => print("$name $version");')
-              ])
-            ];
-          })))
-        ])
-      ];
-    })))
-  ]);
+  _schedule((_) {
+    return Futures.wait(pubspecs.map(_awaitObject))

[Bob Nystrom, 2012/08/23 21:49:13]

Can you just do _awaitObject(pubspects)?

[nweiz, 2012/08/23 22:25:49]

Done.

+        .transform((resolvedPubspecs) {
+      for (var spec in resolvedPubspecs) {
+        var name = spec['name'];
+        var version = spec['version'];
+        var versions = _servedPackages.putIfAbsent(name, () => <String, String>{});

[Bob Nystrom, 2012/08/23 21:49:13]

Long line.

[nweiz, 2012/08/23 22:25:49]

Done.

+        versions[version] = yaml(spec);
+      }
+
+      _servedPackageDir.contents.clear();
+      for (var name in _servedPackages.getKeys()) {
+        _servedPackageDir.contents.addAll([
+          file('$name.json',
+            JSON.stringify({'versions': _servedPackages[name].getKeys()})),

[Bob Nystrom, 2012/08/23 21:49:13]

+2

[nweiz, 2012/08/23 22:25:49]

Done.

+          dir(name, [
+            dir('versions', flatten(_servedPackages[name].getKeys().map((version) {

[Bob Nystrom, 2012/08/23 21:49:13]

Lone line.

[nweiz, 2012/08/23 22:25:49]

Done.

+              return [
+                file('$version.yaml', _servedPackages[name][version]),
+                tar('$version.tar.gz', [
+                  file('pubspec.yaml', _servedPackages[name][version]),
+                  file('$name.dart', 'main() => print("$name $version");')
+                ])
+              ];
+            })))
+          ])
+        ]);
+      }
+    });
+  });
 }
 
 /** Converts [value] into a YAML string. */
@@ -204,7 +254,8 @@ Map package(String name, String version, [List dependencies]) {
  * repository.
  */
 Map dependency(String name, [String versionConstraint]) {
-  var dependency = {"repo": {"name": name, "url": "http://localhost:3123"}};
+  var url = port.transform((p) => "http://localhost:$p");
+  var dependency = {"repo": {"name": name, "url": url}};
   if (versionConstraint != null) dependency["version"] = versionConstraint;
   return dependency;
 }
@@ -271,7 +322,9 @@ DirectoryDescriptor cacheDir(Map packages) {
     }
   });
   return dir(cachePath, [
-    dir('repo', [dir('localhost%583123', contents)])
+    dir('repo', [
+      async(port.transform((p) => dir('localhost%58$p', contents)))
+    ])
   ]);
 }