sdk/lib/_internal/pub/lib/src/command/deps.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.

library pub.command.list;

import 'dart:async';
import 'dart:collection';

import '../ascii_tree.dart' as tree;
import '../command.dart';
import '../log.dart' as log;
import '../package.dart';
import '../package_graph.dart';
import '../utils.dart';

/// Handles the `deps` pub command.
class DepsCommand extends PubCommand {
  String get description => "Print package dependencies.";
  List<String> get aliases => const ["dependencies", "tab"];
  String get usage => "pub deps";

  /// The loaded package graph.
  PackageGraph _graph;

  /// The [StringBuffer] used to accumulate the output.
  StringBuffer _buffer;

  DepsCommand() {
    commandParser.addOption("style", abbr: "s",
        help: "How output should be displayed.",
        allowed: ["compact", "tree", "list"],
        defaultsTo: "tree");
  }

  Future onRun() {
    return entrypoint.loadPackageGraph().then((graph) {
      _graph = graph;
      _buffer = new StringBuffer();

      _buffer.writeln(_labelPackage(entrypoint.root));

      switch (commandOptions["style"]) {
        case "compact": _outputCompact(); break;
        case "list": _outputList(); break;
        case "tree": _outputTree(); break;
      }

      log.message(_buffer);
    });
  }

  /// Outputs a list of all of the package's immediate, dev, override, and
  /// transitive dependencies.
  ///
  /// For each dependency listed, *that* package's immediate dependencies are
  /// shown. Unlike [_outputList], this prints all of these dependencies on one
  /// line.
  void _outputCompact() {
    var root = entrypoint.root;
    _outputCompactPackages("dependencies",
        root.dependencies.map((dep) => dep.name));
    _outputCompactPackages("dev dependencies",
        root.devDependencies.map((dep) => dep.name));
    _outputCompactPackages("dependency overrides",
        root.dependencyOverrides.map((dep) => dep.name));

    var transitive = _getTransitiveDependencies();
    _outputCompactPackages("transitive dependencies", transitive);
  }

  /// Outputs one section of packages in the compact output.
  _outputCompactPackages(String section, Iterable<String> names) {
    if (names.isEmpty) return;

    _buffer.writeln();
    _buffer.writeln("$section:");
    for (var name in ordered(names)) {
      var package = _graph.packages[name];

      _buffer.write("- ${_labelPackage(package)}");
      if (package.dependencies.isEmpty) {
        _buffer.writeln();
      } else {
        var depNames = package.dependencies.map((dep) => dep.name);
        var depsList = "[${depNames.join(' ')}]";
        _buffer.writeln(" ${log.gray(depsList)}");
      }
    }
  }

  /// Outputs a list of all of the package's immediate, dev, override, and
  /// transitive dependencies.
  ///
  /// For each dependency listed, *that* package's immediate dependencies are
  /// shown.
  void _outputList() {
    var root = entrypoint.root;
    _outputListSection("dependencies",
        root.dependencies.map((dep) => dep.name));
    _outputListSection("dev dependencies",
        root.devDependencies.map((dep) => dep.name));
    _outputListSection("dependency overrides",
        root.dependencyOverrides.map((dep) => dep.name));

    var transitive = _getTransitiveDependencies();
    if (transitive.isEmpty) return;

    _outputListSection("transitive dependencies", ordered(transitive));
  }

  /// Outputs one section of packages in the list output.
  _outputListSection(String name, Iterable<String> deps) {
    if (deps.isEmpty) return;

    _buffer.writeln();
    _buffer.writeln("$name:");

    for (var name in deps) {
      var package = _graph.packages[name];
      _buffer.writeln("- ${_labelPackage(package)}");

      for (var dep in package.dependencies) {
        _buffer.writeln(
            "  - ${log.bold(dep.name)} ${log.gray(dep.constraint)}");
      }
    }
  }

  /// Generates a dependency tree for the root package.
  ///
  /// If a package is encountered more than once (i.e. a shared or circular
  /// dependency), later ones are not traversed. This is done in breadth-first
  /// fashion so that a package will always be expanded at the shallowest
  /// depth that it appears at.
  void _outputTree() {
    // The work list for the breadth-first traversal. It contains the package
    // being added to the tree, and the parent map that will receive that
    // package.
    var toWalk = new Queue<Pair<Package, Map>>();
    var visited = new Set<String>();

    // Start with the root dependencies.
    var packageTree = {};
    for (var dep in entrypoint.root.immediateDependencies) {
      toWalk.add(new Pair(_graph.packages[dep.name], packageTree));
    }

    // Do a breadth-first walk to the dependency graph.
    while (toWalk.isNotEmpty) {
      var pair = toWalk.removeFirst();
      var package = pair.first;
      var map = pair.last;

      if (visited.contains(package.name)) {
        map[log.gray('${package.name}...')] = {};
        continue;
      }

      visited.add(package.name);

      // Populate the map with this package's dependencies.
      var childMap = {};
      map[_labelPackage(package)] = childMap;

      for (var dep in package.dependencies) {
        toWalk.add(new Pair(_graph.packages[dep.name], childMap));
      }
    }

    _buffer.write(tree.fromMap(packageTree, showAllChildren: true));
  }

  String _labelPackage(Package package) =>
      "${log.bold(package.name)} ${package.version}";

  /// Gets the names of the non-immediate dependencies of the root package.
  Set<String> _getTransitiveDependencies() {
    var transitive = _graph.packages.keys.toSet();
    var root = entrypoint.root;
    transitive.remove(root.name);
    transitive.removeAll(root.dependencies.map((dep) => dep.name));
    transitive.removeAll(root.devDependencies.map((dep) => dep.name));
    transitive.removeAll(root.dependencyOverrides.map((dep) => dep.name));
    return transitive;
  }
}