Refactor test servers to make them less global.

test/serve_packages.dart

-// Copyright (c) 2014, 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 'package:path/path.dart' as p;
-import 'package:pub/src/io.dart';
-import 'package:pub/src/utils.dart';
-import 'package:pub_semver/pub_semver.dart';
-import 'package:scheduled_test/scheduled_test.dart';
-import 'package:yaml/yaml.dart';
-
-import 'descriptor.dart' as d;
-import 'test_pub.dart';
-
-/// The [d.DirectoryDescriptor] describing the server layout of `/api/packages`
-/// on the test server.
-///
-/// This contains metadata for packages that are being served via
-/// [servePackages]. It's `null` if [servePackages] has not yet been called for
-/// this test.
-d.DirectoryDescriptor _servedApiPackageDir;
-
-/// The [d.DirectoryDescriptor] describing the server layout of `/packages` on
-/// the test server.
-///
-/// This contains the tarballs for packages that are being served via
-/// [servePackages]. It's `null` if [servePackages] has not yet been called for
-/// this test.
-d.DirectoryDescriptor _servedPackageDir;
-
-/// The current [PackageServerBuilder] that a user uses to specify which package
-/// to serve.
-///
-/// This is preserved over multiple calls to [servePackages] within the same
-/// test so that additional packages can be added.
-PackageServerBuilder _builder;
-
-/// Creates an HTTP server that replicates the structure of pub.dartlang.org.
-///
-/// Calls [callback] with a [PackageServerBuilder] that's used to specify
-/// which packages to serve.
-///
-/// If [replace] is false, subsequent calls to [servePackages] will add to the
-/// set of packages that are being served. Previous packages will continue to be
-/// served. Otherwise, the previous packages will no longer be served.
-void servePackages(void callback(PackageServerBuilder builder),
-    {bool replace: false}) {
-  if (_servedPackageDir == null) {
-    _builder = new PackageServerBuilder();
-    _servedApiPackageDir = d.dir('packages', []);
-    _servedPackageDir = d.dir('packages', []);
-    serve([
-      d.dir('api', [_servedApiPackageDir]),
-      _servedPackageDir
-    ]);
-
-    currentSchedule.onComplete.schedule(() {
-      _builder = null;
-      _servedApiPackageDir = null;
-      _servedPackageDir = null;
-    }, 'cleaning up served packages');
-  }
-
-  schedule(() {
-    if (replace) _builder = new PackageServerBuilder();
-    callback(_builder);
-    return _builder._await().then((resolvedPubspecs) {
-      _servedApiPackageDir.contents.clear();
-      _servedPackageDir.contents.clear();
-      _builder._packages.forEach((name, versions) {
-        _servedApiPackageDir.contents.addAll([
-          d.file('$name', JSON.encode({
-            'name': name,
-            'uploaders': ['nweiz@google.com'],
-            'versions': versions.map((version) =>
-                packageVersionApiMap(version.pubspec)).toList()
-          })),
-          d.dir(name, [
-            d.dir('versions', versions.map((version) {
-              return d.file(version.version.toString(), JSON.encode(
-                  packageVersionApiMap(version.pubspec, full: true)));
-            }))
-          ])
-        ]);
-
-        _servedPackageDir.contents.add(d.dir(name, [
-          d.dir('versions', versions.map((version) =>
-              d.tar('${version.version}.tar.gz', version.contents)))
-        ]));
-      });
-    });
-  }, 'initializing the package server');
-}
-
-/// Like [servePackages], but instead creates an empty server with no packages
-/// registered.
-///
-/// This will always replace a previous server.
-void serveNoPackages() => servePackages((_) {}, replace: true);
-
-/// A shortcut for [servePackages] that serves the version of barback used by
-/// pub.
-void serveBarback() {
-  servePackages((builder) {
-    builder.serveRealPackage('barback');
-  });
-}
-
-/// A builder for specifying which packages should be served by [servePackages].
-class PackageServerBuilder {
-  /// A map from package names to a list of concrete packages to serve.
-  final _packages = new Map<String, List<_ServedPackage>>();
-
-  /// A group of futures from [serve] calls.
-  ///
-  /// This should be accessed by calling [_awair].
-  var _futures = new FutureGroup();
-
-  /// Specifies that a package named [name] with [version] should be served.
-  ///
-  /// If [deps] is passed, it's used as the "dependencies" field of the pubspec.
-  /// If [pubspec] is passed, it's used as the rest of the pubspec. Either of
-  /// these may recursively contain Futures.
-  ///
-  /// If [contents] is passed, it's used as the contents of the package. By
-  /// default, a package just contains a dummy lib directory.
-  void serve(String name, String version, {Map deps, Map pubspec,
-      Iterable<d.Descriptor> contents}) {
-    _futures.add(Future.wait([
-      awaitObject(deps),
-      awaitObject(pubspec)
-    ]).then((pair) {
-      var resolvedDeps = pair.first;
-      var resolvedPubspec = pair.last;
-
-      var pubspecFields = {
-        "name": name,
-        "version": version
-      };
-      if (resolvedPubspec != null) pubspecFields.addAll(resolvedPubspec);
-      if (resolvedDeps != null) pubspecFields["dependencies"] = resolvedDeps;
-
-      if (contents == null) contents = [d.libDir(name, "$name $version")];
-      contents = [d.file("pubspec.yaml", yaml(pubspecFields))]
-          ..addAll(contents);
-
-      var packages = _packages.putIfAbsent(name, () => []);
-      packages.add(new _ServedPackage(pubspecFields, contents));
-    }));
-  }
-
-  /// Serves the versions of [package] and all its dependencies that are
-  /// currently depended on by pub.
-  void serveRealPackage(String package) {
-    _addPackage(name) {
-      if (_packages.containsKey(name)) return;
-      _packages[name] = [];
-
-      var root = packagePath(name);
-      var pubspec = new Map.from(loadYaml(
-          readTextFile(p.join(root, 'pubspec.yaml'))));
-
-      // Remove any SDK constraints since we don't have a valid SDK version
-      // while testing.
-      pubspec.remove('environment');
-
-      _packages[name].add(new _ServedPackage(pubspec, [
-        d.file('pubspec.yaml', yaml(pubspec)),
-        new d.DirectoryDescriptor.fromFilesystem('lib', p.join(root, 'lib'))
-      ]));
-
-      if (pubspec.containsKey('dependencies')) {
-        pubspec['dependencies'].keys.forEach(_addPackage);
-      }
-    }
-
-    _addPackage(package);
-  }
-
-  /// Returns a Future that completes once all the [serve] calls have been fully
-  /// processed.
-  Future _await() {
-    if (_futures.futures.isEmpty) return new Future.value();
-    return _futures.future.then((_) {
-      _futures = new FutureGroup();
-    });
-  }
-}
-
-/// A package that's intended to be served.
-class _ServedPackage {
-  final Map pubspec;
-  final List<d.Descriptor> contents;
-
-  Version get version => new Version.parse(pubspec['version']);
-
-  _ServedPackage(this.pubspec, this.contents);
-}