Support removing dead packages with pub install.

Review URL: https://chromiumcodereview.appspot.com//10867070

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@11356 260f80e4-7a28-3924-810f-c04153c831b5

utils/pub/entrypoint.dart

@@ -143,10 +143,12 @@ class Entrypoint {
    * [LockFile].
    */
   Future _installDependencies(List<PackageId> packageVersions) {
-    return Futures.wait(packageVersions.map((id) {
-      if (id.source is RootSource) return new Future.immediate(id);
-      return install(id);
-    })).chain(_saveLockFile).chain(_installSelfReference);
+    return _removeUnusedDependencies(packageVersions).chain((_) {
+      return Futures.wait(packageVersions.map((id) {
+        if (id.source is RootSource) return new Future.immediate(id);
+        return install(id);
+      }));
+    }).chain(_saveLockFile).chain(_installSelfReference);
   }
 
   /**
@@ -179,6 +181,27 @@ class Entrypoint {
     return completer.future;
   }
 
+  /**
+   * Removes all dependencies that are no longer depended on from the `packages`
+   * directory. [packageIds] is a list of all packages that are still depended
+   * on.
+   */
+  Future _removeUnusedDependencies(List<PackageId> packageIds) {
+    var dependenciesToKeep = packageIds.map((id) => id.name);
+
+    return dirExists(path).chain((exists) {
+      if (exists) return listDir(path);
+      return new Future.immediate([]);
+    }).chain((existingDependencies) {
+      existingDependencies = existingDependencies.map(basename);
+      var dependenciesToRemove =
+          new List.from(setMinus(existingDependencies, dependenciesToKeep));
+      return Futures.wait(dependenciesToRemove.map((dependency) {
+        return deleteDir(join(path, dependency));
+      }));
+    });
+  }
+
   /**
    * Saves a list of concrete package versions to the `pubspec.lock` file.
    */

utils/pub/utils.dart

@@ -80,6 +80,16 @@ only(Iterable iter) {
   return obj;
 }
 
+/**
+ * Returns a set containing all elements in [minuend] that are not in
+ * [subtrahend].
+ */
+Set setMinus(Collection minuend, Collection subtrahend) {
+  var minuendSet = new Set.from(minuend);
+  minuendSet.removeAll(subtrahend);
+  return minuendSet;
+}
+
 /**
  * Replace each instance of [matcher] in [source] with the return value of [fn].
  */

utils/tests/pub/pub_install_repo_test.dart

@@ -229,4 +229,104 @@ main() {
 
     run();
   });
+
+  test("removes a dependency that's been removed from the pubspec", () {
+    servePackages([
+      package("foo", "1.0.0"),
+      package("bar", "1.0.0")
+    ]);
+
+    appDir([dependency("foo"), dependency("bar")]).scheduleCreate();
+
+    schedulePub(args: ['install'],
+        output: const RegExp(@"Dependencies installed!$"));
+
+    packagesDir({
+      "foo": "1.0.0",
+      "bar": "1.0.0"
+    }).scheduleValidate();
+
+    appDir([dependency("foo")]).scheduleCreate();
+
+    schedulePub(args: ['install'],
+        output: const RegExp(@"Dependencies installed!$"));
+
+    packagesDir({
+      "foo": "1.0.0",
+      "bar": null
+    }).scheduleValidate();
+
+    run();
+  });
+
+  test("removes a transitive dependency that's no longer depended on", () {
+    servePackages([
+      package("foo", "1.0.0", [dependency("shared-dep")]),
+      package("bar", "1.0.0", [
+        dependency("shared-dep"),
+        dependency("bar-dep")
+      ]),
+      package("shared-dep", "1.0.0"),
+      package("bar-dep", "1.0.0")
+    ]);
+
+    appDir([dependency("foo"), dependency("bar")]).scheduleCreate();
+
+    schedulePub(args: ['install'],
+        output: const RegExp(@"Dependencies installed!$"));
+
+    packagesDir({
+      "foo": "1.0.0",
+      "bar": "1.0.0",
+      "shared-dep": "1.0.0",
+      "bar-dep": "1.0.0",
+    }).scheduleValidate();
+
+    appDir([dependency("foo")]).scheduleCreate();
+
+    schedulePub(args: ['install'],
+        output: const RegExp(@"Dependencies installed!$"));
+
+    packagesDir({
+      "foo": "1.0.0",
+      "bar": null,
+      "shared-dep": "1.0.0",
+      "bar-dep": null,
+    }).scheduleValidate();
+
+    run();
+  });
+
+  test("doesn't update dependencies whose constraints have been removed", () {
+    servePackages([
+      package("foo", "1.0.0", [dependency("shared-dep")]),
+      package("bar", "1.0.0", [dependency("shared-dep", "<2.0.0")]),
+      package("shared-dep", "1.0.0"),
+      package("shared-dep", "2.0.0")
+    ]);
+
+    appDir([dependency("foo"), dependency("bar")]).scheduleCreate();
+
+    schedulePub(args: ['install'],
+        output: const RegExp(@"Dependencies installed!$"));
+
+    packagesDir({
+      "foo": "1.0.0",
+      "bar": "1.0.0",
+      "shared-dep": "1.0.0"
+    }).scheduleValidate();
+
+    appDir([dependency("foo")]).scheduleCreate();
+
+    schedulePub(args: ['install'],
+        output: const RegExp(@"Dependencies installed!$"));
+
+    packagesDir({
+      "foo": "1.0.0",
+      "bar": null,
+      "shared-dep": "1.0.0"
+    }).scheduleValidate();
+
+    run();
+  });
 }

utils/tests/pub/pub_update_repo_test.dart

@@ -75,4 +75,104 @@ main() {
 
     run();
   });
+
+  test("removes a dependency that's been removed from the pubspec", () {
+    servePackages([
+      package("foo", "1.0.0"),
+      package("bar", "1.0.0")
+    ]);
+
+    appDir([dependency("foo"), dependency("bar")]).scheduleCreate();
+
+    schedulePub(args: ['update'],
+        output: const RegExp(@"Dependencies updated!$"));
+
+    packagesDir({
+      "foo": "1.0.0",
+      "bar": "1.0.0"
+    }).scheduleValidate();
+
+    appDir([dependency("foo")]).scheduleCreate();
+
+    schedulePub(args: ['update'],
+        output: const RegExp(@"Dependencies updated!$"));
+
+    packagesDir({
+      "foo": "1.0.0",
+      "bar": null
+    }).scheduleValidate();
+
+    run();
+  });
+
+  test("removes a transitive dependency that's no longer depended on", () {
+    servePackages([
+      package("foo", "1.0.0", [dependency("shared-dep")]),
+      package("bar", "1.0.0", [
+        dependency("shared-dep"),
+        dependency("bar-dep")
+      ]),
+      package("shared-dep", "1.0.0"),
+      package("bar-dep", "1.0.0")
+    ]);
+
+    appDir([dependency("foo"), dependency("bar")]).scheduleCreate();
+
+    schedulePub(args: ['update'],
+        output: const RegExp(@"Dependencies updated!$"));
+
+    packagesDir({
+      "foo": "1.0.0",
+      "bar": "1.0.0",
+      "shared-dep": "1.0.0",
+      "bar-dep": "1.0.0",
+    }).scheduleValidate();
+
+    appDir([dependency("foo")]).scheduleCreate();
+
+    schedulePub(args: ['update'],
+        output: const RegExp(@"Dependencies updated!$"));
+
+    packagesDir({
+      "foo": "1.0.0",
+      "bar": null,
+      "shared-dep": "1.0.0",
+      "bar-dep": null,
+    }).scheduleValidate();
+
+    run();
+  });
+
+  test("updates dependencies whose constraints have been removed", () {
+    servePackages([
+      package("foo", "1.0.0", [dependency("shared-dep")]),
+      package("bar", "1.0.0", [dependency("shared-dep", "<2.0.0")]),
+      package("shared-dep", "1.0.0"),
+      package("shared-dep", "2.0.0")
+    ]);
+
+    appDir([dependency("foo"), dependency("bar")]).scheduleCreate();
+
+    schedulePub(args: ['update'],
+        output: const RegExp(@"Dependencies updated!$"));
+
+    packagesDir({
+      "foo": "1.0.0",
+      "bar": "1.0.0",
+      "shared-dep": "1.0.0"
+    }).scheduleValidate();
+
+    appDir([dependency("foo")]).scheduleCreate();
+
+    schedulePub(args: ['update'],
+        output: const RegExp(@"Dependencies updated!$"));
+
+    packagesDir({
+      "foo": "1.0.0",
+      "bar": null,
+      "shared-dep": "2.0.0"
+    }).scheduleValidate();
+
+    run();
+  });
 }

utils/tests/pub/test_pub.dart

@@ -55,6 +55,11 @@ GitRepoDescriptor git(Pattern name, [List<Descriptor> contents]) =>
 TarFileDescriptor tar(Pattern name, [List<Descriptor> contents]) =>
     new TarFileDescriptor(name, contents);
 
+/**
+ * Creates a new [NothingDescriptor] with [name].
+ */
+NothingDescriptor nothing(String name) => new NothingDescriptor(name);
+
 /**
  * The current [HttpServer] created using [serve].
  */
@@ -301,11 +306,17 @@ DirectoryDescriptor gitPackageCacheDir(String name, [int modifier]) {
  * Describes 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.
+ *
+ * A package with a null version should not be installed.
  */
 DirectoryDescriptor packagesDir(Map<String, String> packages) {
   var contents = <Descriptor>[];
   packages.forEach((name, version) {
-    contents.add(packageDir(name, version));
+    if (version == null) {
+      contents.add(nothing(name));
+    } else {
+      contents.add(packageDir(name, version));
+    }
   });
   return dir(packagesPath, contents);
 }
@@ -1021,6 +1032,31 @@ class TarFileDescriptor extends Descriptor {
   }
 }
 
+/**
+ * A descriptor that validates that no file exists with the given name.
+ */
+class NothingDescriptor extends Descriptor {
+  NothingDescriptor(String name) : super(name);
+
+  Future create(dir) => new Future.immediate(null);
+  Future delete(dir) => new Future.immediate(null);
+
+  Future validate(String dir) {
+    return exists(join(dir, name)).transform((exists) {
+      if (exists) Expect.fail('File $name in $dir should not exist.');
+    });
+  }
+
+  InputStream load(List<String> path) {
+    if (path.isEmpty()) {
+      throw "Can't load the contents of $name: it doesn't exist.";
+    } else {
+      throw "Can't load ${Strings.join(path, '/')} from within $name: $name "
+        "doesn't exist.";
+    }
+  }
+}
+
 /**
  * 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.