Add the package implementation.

test/packages_handler_test.dart

+// Copyright (c) 2016, 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:io';
+
+import 'package:package_resolver/package_resolver.dart';
+import 'package:path/path.dart' as p;
+import 'package:shelf/shelf.dart';
+import 'package:shelf_packages_handler/shelf_packages_handler.dart';
+import 'package:test/test.dart';
+
+void main() {
+  var dir;
+  setUp(() {
+    dir = Directory.systemTemp
+        .createTempSync("shelf_packages_handler_test")
+        .path;
+    new Directory(dir).createSync();
+    new Directory("$dir/foo").createSync();
+    new File("$dir/foo/foo.dart")
+        .writeAsStringSync("void main() => print('in foo');");
+  });
+
+  tearDown(() {
+    new Directory(dir).deleteSync(recursive: true);
+  });
+
+  group("packagesHandler", () {
+    test("defaults to the current method of package resolution", () async {
+      var handler = packagesHandler();
+      var request = new Request(
+          "GET",
+          Uri.parse(
+              "http://example.com/shelf_packages_handler/"
+              "shelf_packages_handler.dart"));
+      var response = await handler(request);
+      expect(response.statusCode, equals(200));
+      expect(await response.readAsString(),
+          contains("Handler packagesHandler"));
+    });
+
+    group("with a package root", () {
+      var resolver;
+      setUp(() => resolver = new PackageResolver.root(p.toUri(dir)));
+
+      test("looks up a real file", () async {
+        var handler = packagesHandler(resolver: resolver);
+        var request = new Request(
+            "GET", Uri.parse("http://example.com/foo/foo.dart"));
+        var response = await handler(request);
+        expect(response.statusCode, equals(200));
+        expect(await response.readAsString(), contains("in foo"));
+      });
+
+      test("404s for a nonexistent file", () async {
+        var handler = packagesHandler(resolver: resolver);
+        var request = new Request(
+            "GET", Uri.parse("http://example.com/foo/bar.dart"));
+        var response = await handler(request);
+        expect(response.statusCode, equals(404));
+      });
+    });
+
+    group("with a package config", () {
+      var resolver;
+      setUp(() {
+        resolver = new PackageResolver.config({"foo": p.toUri("$dir/foo")});
+      });
+
+      test("looks up a real file", () async {
+        var handler = packagesHandler(resolver: resolver);
+        var request = new Request(
+            "GET", Uri.parse("http://example.com/foo/foo.dart"));
+        var response = await handler(request);
+        expect(response.statusCode, equals(200));
+        expect(await response.readAsString(), contains("in foo"));
+      });
+
+      test("404s for a nonexistent package", () async {
+        var handler = packagesHandler(resolver: resolver);
+        var request = new Request(
+            "GET", Uri.parse("http://example.com/bar/foo.dart"));
+        var response = await handler(request);
+        expect(response.statusCode, equals(404));
+      });
+
+      test("404s for a nonexistent file", () async {
+        var handler = packagesHandler(resolver: resolver);
+        var request = new Request(
+            "GET", Uri.parse("http://example.com/foo/bar.dart"));
+        var response = await handler(request);
+        expect(response.statusCode, equals(404));
+      });
+    });
+  });
+
+  group("packagesDirHandler", () {
+    test("supports a directory at the root of the URL", () async {
+      var handler = packagesDirHandler();
+      var request = new Request(
+          "GET",
+          Uri.parse(
+              "http://example.com/packages/shelf_packages_handler/"
+              "shelf_packages_handler.dart"));
+      var response = await handler(request);
+      expect(response.statusCode, equals(200));
+      expect(await response.readAsString(),
+          contains("Handler packagesHandler"));
+    });
+
+    test("supports a directory deep in the URL", () async {
+      var handler = packagesDirHandler();
+      var request = new Request(
+          "GET",
+          Uri.parse(
+              "http://example.com/foo/bar/very/deep/packages/"
+              "shelf_packages_handler/shelf_packages_handler.dart"));
+      var response = await handler(request);
+      expect(response.statusCode, equals(200));
+      expect(await response.readAsString(),
+          contains("Handler packagesHandler"));
+    });
+
+    test("404s for a URL without a packages directory", () async {
+      var handler = packagesDirHandler();
+      var request = new Request(
+          "GET",
+          Uri.parse(
+              "http://example.com/shelf_packages_handler/"
+              "shelf_packages_handler.dart"));
+      var response = await handler(request);
+      expect(response.statusCode, equals(404));
+    });
+
+    test("404s for a non-existent file within a packages directory", () async {
+      var handler = packagesDirHandler();
+      var request = new Request(
+          "GET",
+          Uri.parse(
+              "http://example.com/packages/shelf_packages_handler/"
+              "non_existent.dart"));
+      var response = await handler(request);
+      expect(response.statusCode, equals(404));
+    });
+  });
+}