Add test of some package-config configurations.

tests/standalone/packages_file_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:async";
+import "dart:io";
+import "dart:isolate";
+import "dart:convert" show JSON;
+import "package:path/path.dart" as p;
+import "package:expect/expect.dart";
+import "package:async_helper/async_helper.dart";
+
+main() async {
+  asyncStart();
+
+  await test("file: no resolution",

[floitsch, 2016/05/26 19:09:55]

Add a comment on the first test that explains that '%file' and '%http' are
replaced with the file and http root (respectively).

+    "%file/main.dart",
+    file: {"main": testMain},
+    expect: {"foo.x": null});
+
+  // An HTTP script with no ".packages" file assumes a "packages" dir.
+  await test("http: no resolution", "%http/main.dart",
+    http: {"main": testMain},
+    expect: {
+      // "foo": null,
+      "foo/": "%http/packages/foo/",
+      "foo/bar": "%http/packages/foo/bar",
+      "foo.x": null,
+    });
+
+  for (var scheme in ["file", "http"]) {
+
+    testScheme(name, main, {expect, files, args, root, config}) {
+      return test("$scheme: $name", main, expect: expect,
+        root: root, config: config, args: args,
+        file: scheme == "file" ? files : null,
+        http: scheme == "http" ? files : null);
+    }
+
+    {
+      var files = {"main": testMain, "packages": fooPackage};
+      // Expect implicitly detected package dir.
+      await testScheme("implicit packages dir","%$scheme/main.dart",
+        files: files,
+        expect: {
+          "iroot": "%$scheme/packages/",
+          // "foo": null,
+          "foo/": "%$scheme/packages/foo/",
+          "foo/bar": "%$scheme/packages/foo/bar",
+        });
+    }
+
+    {
+      var files = {"sub": {"main": testMain, "packages": fooPackage},
+                   ".packages": ""};

[floitsch, 2016/05/26 19:09:56]

Provide comment what an empty ".packages" should do.
(It seems like we just ignore it then).

[Lasse Reichstein Nielsen, 2016/05/27 10:53:56]

Will do. 
We don't ignore it - the test should not find and use it, but if it did, it
would mean that no package names could be resolved.

+      // Expect implicitly detected package dir.
+      await testScheme("implicit packages dir 2", "%$scheme/sub/main.dart",
+        files: files,
+        expect: {
+          "iroot": "%$scheme/sub/packages/",
+          // "foo": null,
+          "foo/": "%$scheme/sub/packages/foo/",
+          "foo/bar": "%$scheme/sub/packages/foo/bar",
+        });
+    }
+
+    {
+      var files = {"main": testMain,
+                   ".packages": "foo:pkgs/foo/",
+                   "pkgs": fooPackage};
+      await testScheme("implicit .packages file", "%$scheme/main.dart",
+        files: files,
+        expect: {
+          "iconf": "%$scheme/.packages",
+          // "foo": null,
+          "foo/": "%$scheme/pkgs/foo/",
+          "foo/bar": "%$scheme/pkgs/foo/bar",
+        });
+    }
+
+    {
+      var files = {"main": testMain,
+                   ".packages": "foo:packages/foo/",
+                   "packages": fooPackage,
+                   "pkgs": fooPackage};
+      await testScheme("explicit package root, no slash", "%$scheme/main.dart",
+        files: files,
+        root: "%$scheme/pkgs",
+        expect: {
+          "proot": "%$scheme/pkgs/",
+          "iroot": "%$scheme/pkgs/",
+          // "foo": null,
+          "foo/": "%$scheme/pkgs/foo/",
+          "foo/bar": "%$scheme/pkgs/foo/bar",
+        });
+    }
+
+    {
+      var files = {"main": testMain,
+                   ".packages": "foo:packages/foo/",
+                   "packages": fooPackage,
+                   "pkgs": fooPackage};
+      await testScheme("explicit package root, slash", "%$scheme/main.dart",
+        files: files,
+        root: "%$scheme/pkgs",
+        expect: {
+          "proot": "%$scheme/pkgs/",
+          "iroot": "%$scheme/pkgs/",
+          // "foo": null,
+          "foo/": "%$scheme/pkgs/foo/",
+          "foo/bar": "%$scheme/pkgs/foo/bar",
+        });
+    }
+
+    {
+      var files = {"main": testMain,
+                   ".packages": "foo:packages/foo/",
+                   "packages": fooPackage,
+                   ".pkgs": "foo:pkgs/foo/",
+                   "pkgs": fooPackage};
+      await testScheme("explicit package config file", "%$scheme/main.dart",
+        files: files,
+        config: "%$scheme/.pkgs",
+        expect: {
+          "pconf": "%$scheme/.pkgs",
+          "iconf": "%$scheme/.pkgs",
+          // "foo": null,
+          "foo/": "%$scheme/pkgs/foo/",
+          "foo/bar": "%$scheme/pkgs/foo/bar",
+        });
+    }
+
+    {
+      var files = {"main": testMain,
+                   ".packages": "foo:packages/foo/",
+                   "packages": fooPackage,
+                   "pkgs": fooPackage};
+      var dataUri = "data:,foo:%$scheme/pkgs/foo/\n";
+      await testScheme("explicit data: config file", "%$scheme/main.dart",
+        files: files,
+        config: dataUri,
+        expect: {
+          "pconf": dataUri,
+          "iconf": dataUri,
+          // "foo": null,
+          "foo/": "%$scheme/pkgs/foo/",
+          "foo/bar": "%$scheme/pkgs/foo/bar",
+        });
+    }
+  }
+
+  {
+    // With a file: URI, the lookup checks for a .packages file in superdirs.
+    var files = {"sub": { "main": testMain },
+                 ".packages": "foo:pkgs/foo/",
+                 "pkgs": fooPackage};
+    await test("file: implicit .packages file in ..", "%file/sub/main.dart",
+      file: files,
+      expect: {
+        "iconf": "%file/.packages",
+        // "foo": null,
+        "foo/": "%file/pkgs/foo/",
+        "foo/bar": "%file/pkgs/foo/bar",
+      });
+  }
+
+  {
+    // With a non-file: URI, the lookup assumes a packges/ dir.

[floitsch, 2016/05/26 19:09:56]

packages

[Lasse Reichstein Nielsen, 2016/05/27 10:53:56]

I like to use .packages to signify the file and packages/ to signify the
"packages" directory.

+    var files = {"sub": { "main": testMain },
+                 ".packages": "foo:pkgs/foo/",
+                 "pkgs": fooPackage};
+    // Expect implicitly detected .package file.
+    await test("http: implicit packages dir", "%http/sub/main.dart",
+      http: files,
+      expect: {
+        "iroot": "%http/sub/packages/",
+        // "foo": null,
+        "foo/": "%http/sub/packages/foo/",
+        "foo/bar": "%http/sub/packages/foo/bar",
+        "foo.x": null,
+      });
+  }
+
+
+  if (failingTests.isNotEmpty) {
+    print("Errors found in tests:\n  ${failingTests.join("\n  ")}\n");
+    exit(255);
+  }
+  asyncEnd();
+}
+
+// ---------------------------------------------------------
+// Helper functionality.
+
+var failingTests = new Set();
+
+var fileHttpRegexp = new RegExp(r"%(?:file|http)/");
+
+Future test(String name, String main,
+            {String root, String config, List<String> args,
+             Map file, Map http, Map expect}) async {
+  String fileRoot = "<no files configured>";
+  String httpRoot = "<not http server configured>";

[floitsch, 2016/05/26 19:09:56]

no

[Lasse Reichstein Nielsen, 2016/05/27 10:53:56]

Will do.

+
+  String fixPaths(String source) {
+    if (source == null) return null;
+    var result = source.replaceAllMapped(fileHttpRegexp, (match) {
+      if (source.startsWith("file", match.start + 1)) return fileRoot;
+      return httpRoot;
+    });
+    return result;
+  }
+
+  Directory tmpDir;
+  var https;
+  if (file != null) {
+    tmpDir = createTempDir();
+    fileRoot = new Uri.directory(tmpDir.path).toString();
+  }
+  if (http != null) {
+    https = await startServer(http, fixPaths);
+    httpRoot = "http://${https.address.address}:${https.port}/";
+  }
+  if (file != null) {
+    createFiles(tmpDir, file, fixPaths);
+  }
+
+  try {
+    var output = await runDart(fixPaths(main),
+                               root: fixPaths(root),
+                               config: fixPaths(config),
+                               scriptArgs: args?.map(fixPaths));
+    // These expectations are default. If not overridden the value will be
+    // expected to be null. That is, you can't avoid testing the actual
+    // value of these, you can only change what value to expect.
+    // For values not included here (commented out), the result is not tested
+    // unless a value (maybe null) is provided.
+    var expects = {
+       "pconf":   null,
+       "proot":   null,
+       "iconf":   null,
+       "iconf":   null,
+       // "foo":   null,
+       "foo/":    null,
+       "foo/bar": null,
+       "foo.x":  "qux",
+    }..addAll(expect);
+    match(JSON.decode(output), expects, fixPaths, name);
+  } catch (e) {
+    // Unexpected error calling runDart or parsing the result.
+    // Report it and continue.
+    print("ERROR running $name: $e\n$s");
+    failingTests.add(name);
+  } finally {
+    if (https != null) await https.close();
+    if (tmpDir != null) tmpDir.deleteSync(recursive: true);
+  }
+}
+
+
+/// Test that the output of running testMain matches the expectations.
+///
+/// The output is a string which is parse as a JSON literal.
+/// The resulting map is always mapping strings to strings, or possibly `null`.
+/// The expectations can have non-string values other than null,
+/// they are `toString`'ed  before being compared (so the caller can use a URI
+/// or a File/Directory directly as an expectation).
+void match(Map actuals, Map expectations, String fixPaths(String expectation),
+           String name) {
+  for (var key in expectations.keys) {
+    var expectation = fixPaths(expectations[key]?.toString());
+    var actual = actuals[key];
+    if (expectation != actual) {
+      print("ERROR: $name: $key: Expected: <$expectation> Found: <$actual>");
+      failingTests.add(name);
+    }
+  }
+}
+
+/// Script that prints the current state and the result of resolving
+/// a few package URIs. This script will be invoked in different settings,
+/// and the result will be parsed and compared to the expectations.
+const String testMain = r"""
+import "dart:convert" show JSON;
+import "dart:io" show Platform, Directory;
+import "dart:isolate" show Isolate;
+import "package:foo/foo.dart" deferred as foo;
+main(_) async {
+  String platformRoot = await Platform.packageRoot;
+  String platformConfig = await Platform.packageConfig;
+  Directory cwd = Directory.current;
+  Uri script = Platform.script;
+  Uri isolateRoot = await Isolate.packageRoot;
+  Uri isolateConfig = await Isolate.packageConfig;
+  Uri base = Uri.base;
+  Uri res1 = await Isolate.resolvePackageUri(Uri.parse("package:foo"));
+  Uri res2 = await Isolate.resolvePackageUri(Uri.parse("package:foo/"));
+  Uri res3 = await Isolate.resolvePackageUri(Uri.parse("package:foo/bar"));
+  String fooX = await foo
+    .loadLibrary()
+    .timeout(const Duration(seconds: 1))
+    .then((_) => foo.x, onError: (_) => null);
+  print(JSON.encode({
+    "cwd": cwd.path,
+    "base": base?.toString(),
+    "script": script?.toString(),
+    "proot": platformRoot,
+    "pconf": platformConfig,
+    "iroot" : isolateRoot?.toString(),
+    "iconf" : isolateConfig?.toString(),
+    "foo": res1?.toString(),
+    "foo/": res2?.toString(),
+    "foo/bar": res3?.toString(),
+    "foo.x": fooX?.toString(),
+  }));
+}
+""";
+
+/// Script that spawns a new Isolate using Isolate.spawnUri.
+///
+/// Takes URI of target isolate, package config and package root as
+/// command line arguments. Any further arguments are forwarded to the
+/// spawned isolate.
+const String spawnUriMain = r"""

[floitsch, 2016/05/26 19:09:56]

unused.

[Lasse Reichstein Nielsen, 2016/05/27 10:53:56]

Yes. Reserved for later use.
That's the part I'm going to work on immediately after this.

+import "dart:isolate";
+main(args) async {
+  Uri target = Uri.parse(args[0]);
+  Uri conf = args.length > 1 && args[1].isNotEmpty ? Uri.parse(args[1]) : null;
+  Uri root = args.length > 2 && args[2].isNotEmpty ? Uri.parse(args[2]) : null;
+  var restArgs = args.skip(3).toList();
+  var isolate = await Isolate.spawnUri(target, restArgs,
+      packageRoot: root, packageConfig: conf, paused: true);
+  // Wait for isolate to exit before exiting the main isolate.
+  var done = new RawReceivePort();
+  done.handler = (_) { done.close(); };
+  isolate.addExitHandler(done.sendPort);
+  isolate.resume(isolate.pauseCapability);
+}
+""";
+
+/// Script that spawns a new Isolate using Isolate.spawn.
+const String spawnMain = r"""

[floitsch, 2016/05/26 19:09:56]

unused.

[Lasse Reichstein Nielsen, 2016/05/27 10:53:56]

Ditto.

+import "dart:isolate";
+import "testmain.dart" as test;
+main() async {
+  var isolate = await Isolate.spawn(test.main, [], paused: true);
+  // Wait for isolate to exit before exiting the main isolate.
+  var done = new RawReceivePort();
+  done.handler = (_) { done.close(); };
+  isolate.addExitHandler(done.sendPort);
+  isolate.resume(isolate.pauseCapability);
+}
+""";
+
+/// A package directory containing only one package, "foo", with one file.
+const Map fooPackage = const { "foo": const { "foo": "var x = 'qux';" }};
+
+/// Runs the Dart executable with the provided parameters.
+///
+/// Captures and returns the output.
+Future<String> runDart(String script,
+                       {String root, String config,
+                        Iterable<String> scriptArgs}) async {
+  // TODO: Find a way to change CWD before running script.
+  var executable = Platform.executable;
+  var args = [];
+  if (root != null) args..add("-p")..add(root);
+  if (config != null) args..add("--packages=$config");
+  args.add(script);
+  if (scriptArgs != null) {
+    args.addAll(scriptArgs);
+  }
+  return Process.run(executable, args).then((results) {
+    if (results.exitCode != 0) {
+      throw results.stderr;
+    }
+    return results.stdout;
+  });
+}
+
+/// Creates a number of files and subdirectories.
+///
+/// The [content] is the content of the directory itself. The map keys are
+/// names and the values are either strings that represent Dart file contents
+/// or maps that represent subdirectories.
+/// Subdirectories may include a package directory. If [packageDir]
+/// is provided, a `.packages` file is created for the content of that
+/// directory.
+void createFiles(Directory tempDir, Map content, String fixPaths(String text),
+                 [String packageDir]) {
+  Directory createDir(Directory base, String name) {
+    Directory newDir = new Directory(p.join(base.path, name));
+    newDir.createSync();
+    return newDir;
+  }
+
+  void createTextFile(Directory base, String name, String content) {
+    File newFile = new File(p.join(base.path, name));
+    newFile.writeAsStringSync(fixPaths(content));
+  }
+
+  void createRecursive(Directory dir, Map map) {
+    for (var name in map.keys) {
+      var content = map[name];
+      if (content is String) {
+        // If the name starts with "." it's a .packages file, otherwise it's
+        // a dart file. Those are the only files we care about in this test.
+        createTextFile(dir,
+                       name.startsWith(".") ? name : name + ".dart",
+                       content);
+      } else {
+        assert(content is Map);
+        var subdir = createDir(dir, name);
+        createRecursive(subdir, content);
+      }
+    }
+  }
+
+  createRecursive(tempDir, content);
+  if (packageDir != null) {
+    // Unused?
+    Map packages = content[packageDir];
+    var entries =
+        packages.keys.map((key) => "$key:$packageDir/$key").join("\n");
+    createTextFile(tempDir, ".packages", entries);
+  }
+  return tempDir;
+}
+
+/// Start an HTTP server which serves a directory/file structure.
+///
+/// The directories and files are described by [files].
+///
+/// Each map key is an entry in a directory. A `Map` value is a sub-directory
+/// and a `String` value is a text file.
+/// The file contents are run through [fixPaths] to allow them to be self-
+/// referential.
+Future<HttpServer> startServer(Map files, String fixPaths(String text)) async {
+  return (await HttpServer.bind(InternetAddress.LOOPBACK_IP_V4, 0))
+      ..forEach((request) {
+        var result = files;
+        onFailure: {
+          for (var part in request.uri.pathSegments) {
+            if (part.endsWith(".dart")) {
+              part = part.substring(0, part.length - 5);
+            }
+            if (result is Map) {
+              result = result[part];
+            } else {
+              break onFailure;
+            }
+          }
+          if (result is String) {
+            request.response..write(fixPaths(result))
+                            ..close();
+            return;
+          }
+        }
+        request.response..statusCode = HttpStatus.NOT_FOUND
+                        ..close();
+      });
+}
+
+// Counter used to avoid reusing temporary directory names.
+// Some platforms are timer based, and creating two temp-dirs withing a short
+// duration may cause a collision.
+int tmpDirCounter = 0;
+
+Directory createTempDir() {
+  return Directory.systemTemp.createTempSync("pftest-${tmpDirCounter++}-");
+}