Add a number of convenience methods to test_pub.

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 9e8e9d373d0d40e05b10400f2673a2ff11e7311d..10f9104300a5e37d36e214b3c3dd18707c497ee0 100644
--- a/utils/tests/pub/test_pub.dart
+++ b/utils/tests/pub/test_pub.dart
@@ -17,7 +17,10 @@
 
 #import('../../../pkg/unittest/unittest.dart');
 #import('../../lib/file_system.dart', prefix: 'fs');
+#import('../../pub/git_source.dart');
 #import('../../pub/io.dart');
+#import('../../pub/repo_source.dart');
+#import('../../pub/sdk_source.dart');
 #import('../../pub/utils.dart');
 #import('../../pub/yaml/yaml.dart');
 
@@ -122,16 +125,15 @@ Future _closeServer() {
 
 /**
  * Creates an HTTP server that replicates the structure of pub.dartlang.org.
- * [pubspecs] is a list of YAML-format pubspecs representing the packages to
+ * [pubspecs] is a list of unserialized pubspecs representing the packages to
  * serve.
  */
-void servePackages(String host, int port, List<String> pubspecs) {
+void servePackages(String host, int port, List<Map> pubspecs) {
   var packages = <String, Map<String, String>>{};
   pubspecs.forEach((spec) {

[Bob Nystrom, 2012/08/22 16:33:09]

This is mostly a matter of taste, but how about using a regular for-in loop
here? I tend to only use forEach() for maps, or if the body actually needs to be
a first class function. Otherwise, especially with multi-line bodies, I think a
regular loop is a bit easier to read and more familiar to most programmers.

[nweiz, 2012/08/23 18:09:09]

Done.

-    var parsed = loadYaml(spec);
-    var name = parsed['name'];
-    var version = parsed['version'];
-    packages.putIfAbsent(name, () => <String, String>{})[version] = spec;
+    var name = spec['name'];
+    var version = spec['version'];
+    packages.putIfAbsent(name, () => <String, String>{})[version] = yaml(spec);
   });
 
   serve(host, port, [
@@ -155,6 +157,158 @@ void servePackages(String host, int port, List<String> pubspecs) {
   ]);
 }
 
+/** Converts [value] into a YAML string. */
+String yaml(value) => JSON.stringify(value);
+
+/**
+ * Returns a file named `pubspec.yaml` with the given YAML-serialized

[Bob Nystrom, 2012/08/22 16:33:09]

I find the "Returns a" and "Returns the" (especially the latter) a bit confusing
to read. For example "Returns the `packages/` directory containing all the given
[packages]" makes it sound like the packages/ dir already exists and the
function just finds it.

How about "Describes a" instead?

[nweiz, 2012/08/23 18:09:09]

Done.

+ * [contents], which should be a serializable object.
+ *
+ * [contents] may contain [Future]s that resolve to serializable objects, which
+ * may in turn contain [Future]s recursively.
+ */
+Descriptor pubspec(Map contents) {
+  return async(_awaitObject(contents).transform((resolvedContents) =>
+      file("pubspec.yaml", yaml(resolvedContents))));
+}
+
+/**
+ * Returns a file named `pubspec.yaml` for an application package with the given
+ * [dependencies].
+ */
+Descriptor appPubspec(List dependencies) =>
+  pubspec({"dependencies": _dependencyListToMap(dependencies)});
+
+/**
+ * Returns a file named `pubspec.yaml` for a library package with the given
+ * [name], [version], and [dependencies].
+ */
+Descriptor libPubspec(String name, String version, [List dependencies]) =>
+  pubspec(package(name, version, dependencies));
+
+/**
+ * Returns a map representing a library package with the given [name],
+ * [version], and [dependencies].
+ */
+Map package(String name, String version, [List dependencies]) {
+  var package = {"name": name, "version": version};
+  if (dependencies != null) {
+    package["dependencies"] = _dependencyListToMap(dependencies);
+  }
+  return package;
+}
+
+/**
+ * Returns a map representing a dependency on a package in the package
+ * repository.
+ */
+Map dependency(String name, [String versionConstraint]) {
+  var dependency = {"repo": {"name": name, "url": "http://localhost:3123"}};
+  if (versionConstraint != null) dependency["version"] = versionConstraint;
+  return dependency;
+}
+
+/**
+ * Returns a directory for a package installed from the mock package repo. This
+ * directory is of the form found in the `packages/` directory.
+ */
+DirectoryDescriptor packageDir(String name, String version) {
+  return dir(name, [
+    file("$name.dart", 'main() => print("$name $version");')
+  ]);
+}
+
+/**
+ * Returns a directory for a package installed from the mock package server.
+ * This directory is of the form found in the global package cache.
+ */
+DirectoryDescriptor packageCacheDir(String name, String version) {
+  return dir("$name-$version", [
+    file("$name.dart", 'main() => print("$name $version");')
+  ]);
+}
+
+/**
+ * Returns a directory for a Git package. This directory is of the form found in
+ * the global package cache.
+ */
+DirectoryDescriptor gitPackageCacheDir(String name, [int modifier]) {
+  var value = name;
+  if (modifier != null) value = "$name $modifier";
+  return dir(new RegExp("$name${@'-[a-f0-9]+'}"), [
+    file('$name.dart', 'main() => "$value";')
+  ]);
+}
+
+/**
+ * Returns the `packages/` directory containing all the given [packages], which
+ * should be name/version pairs. The packages will be validated against the
+ * format produced by the mock package server.
+ */
+DirectoryDescriptor packagesDir(Map<String, String> packages) {
+  var contents = <Map>[];
+  packages.forEach((name, version) {
+    contents.add(packageDir(name, version));
+  });
+  return dir(packagesPath, contents);
+}
+
+/**
+ * Returns the global package cache directory containing all the given
+ * [packages], which should be name/version pairs. The packages will be
+ * validated against the format produced by the mock package server.
+ *
+ * A package's value may also be a list of versions, in which case all versions
+ * are expected to be installed.
+ */
+DirectoryDescriptor cacheDir(Map packages) {
+  var contents = <Map>[];
+  packages.forEach((name, versions) {
+    if (versions is! List) versions = [versions];
+    for (var version in versions) {
+      contents.add(packageCacheDir(name, version));
+    }
+  });
+  return dir(cachePath, [
+    dir('repo', [dir('localhost%583123', contents)])
+  ]);
+}
+
+/**
+ * Returns the application directory, containing only a pubspec specifying the
+ * given [dependencies].
+ */
+DirectoryDescriptor appDir(List dependencies) =>
+  dir(appPath, [appPubspec(dependencies)]);
+
+/**
+ * Converts a list of dependencies as passed to [package] into a hash as used in
+ * a pubspec.
+ */
+Map _dependencyListToMap(List<Map> dependencies) {
+  var result = <String, Map>{};
+  dependencies.map((dependency) {
+    var sourceName = only(dependency.getKeys());
+    var source;
+    switch (sourceName) {
+    case "git":
+      source = new GitSource();
+      break;
+    case "repo":
+      source = new RepoSource();
+      break;
+    case "sdk":
+      source = new SdkSource('');
+      break;
+    default:
+      throw 'Unknown source "$sourceName"';
+    }
+
+    result[source.packageName(dependency[sourceName])] = dependency;
+  });
+  return result;
+}
+
 /**
  * The path of the package cache directory used for tests. Relative to the
  * sandbox directory.
@@ -584,23 +738,15 @@ class DirectoryDescriptor extends Descriptor {
    * the creation is done.
    */
   Future<Directory> create(parentDir) {
-    final completer = new Completer<Directory>();
-
     // Create the directory.
-    ensureDir(join(parentDir, _stringName)).then((dir) {
-      if (contents == null) {
-        completer.complete(dir);
-      } else {
-        // Recursively create all of its children.
-        final childFutures = contents.map((child) => child.create(dir));
-        Futures.wait(childFutures).then((_) {
-          // Only complete once all of the children have been created too.
-          completer.complete(dir);
-        });
-      }
-    });
+    return ensureDir(join(parentDir, _stringName)).chain((dir) {
+      if (contents == null) return new Future<Directory>.immediate(dir);
 
-    return completer.future;
+      // Recursively create all of its children.
+      final childFutures = contents.map((child) => child.create(dir));
+      // Only complete once all of the children have been created too.
+      return Futures.wait(childFutures).transform((_) => dir);
+    });
   }
 
   /**
@@ -803,6 +949,30 @@ class TarFileDescriptor extends Descriptor {
 }
 
 /**
+ * Takes a simple data structure (composed of [Map]s, [List]s, scalar objects,
+ * and [Future]s) and recursively resolves all the [Future]s contained within.
+ * Completes with the fully resolved structure.

[Bob Nystrom, 2012/08/22 16:33:09]

This is very cool, although it pains me to realize Dart's async model means
we're apparently very slowly reinventing Haskell, one thunk at a time.

[nweiz, 2012/08/23 18:09:09]

Yyyyep.

+ */
+Future _awaitObject(object) {
+  if (object is Future) return object.chain(_awaitObject);

[Bob Nystrom, 2012/08/22 16:33:09]

Took me a while to realize what this case was for. Add:

// Unroll nested futures.

[nweiz, 2012/08/23 18:09:09]

Done.

+  if (object is Collection) return Futures.wait(object.map(_awaitObject));
+  if (object is! Map) return new Future.immediate(object);
+
+  var pairs = <Future<Pair>>[];
+  object.forEach((key, value) {
+    pairs.add(_awaitObject(value)
+        .transform((resolved) => new Pair(key, resolved)));
+  });
+  return Futures.wait(pairs).transform((resolvedPairs) {
+    var map = {};
+    for (var pair in resolvedPairs) {
+      map[pair.first] = pair.last;
+    }
+    return map;
+  });
+}
+
+/**
  * Schedules a callback to be called as part of the test case.
  */
 void _schedule(_ScheduledEvent event) {