Tab completion, handler for install command

- results of the first lookup is cached to
  ~/.bower/completion/install.json
- consider caching in ~/.bower/cache instead, so that cache-clean
  command also removes completion cache.

lib/commands/completion.js

@@ -0,0 +1,102 @@
+// ==========================================
+// BOWER: Completion API
+// ==========================================
+// Copyright 2012 Twitter, Inc
+// Licensed under The MIT License
+// http://opensource.org/licenses/MIT
+// ==========================================
+var Emitter  = require('events').EventEmitter;
+var path     = require('path');
+var nopt     = require('nopt');
+var mkdirp   = require('mkdirp');
+
+var template = require('../util/template');
+var complete = require('../util/completion');
+var config   = require('../core/config');
+var help     = require('./help');
+
+var optionTypes = { help: Boolean };
+var shorthand   = { 'h': ['--help'] };
+
+module.exports = function (argv, env) {
+  env = env || process.env;
+
+  var emitter = new Emitter;
+  var commands = require('../commands');
+
+  // top level flags
+  var flags = ['--no-color', '--help', '--version'];
+
+  var done = function done() {
+    process.nextTick(function () {
+      emitter.emit('end');
+    });
+
+    return emitter;
+  };
+
+  // if the COMP_* isn't in the env, then just dump the script.
+  if (!env.COMP_CWORD) {
+    template('completion').on('data', emitter.emit.bind(emitter, 'end'));
+    return emitter;
+  }
+
+  // parse environment and arguments, returns a hash of completion config.
+  var opts = complete(argv, env);
+
+  // if only one word, complete the list of command or top level flags
+  if (opts.w === 1) {
+    if (opts.word.charAt(0) === '-') complete.log(flags, opts);
+    else complete.log(Object.keys(commands), opts);
+    return done();
+  }
+
+  // try to find the bower command. first thing after all the configs.
+  var parsed = opts.conf = nopt({}, {}, opts.partialWords, 0);
+  var cmd = parsed.argv.remain[0];
+
+  // unable to find a command, complete the lisf of commands
+  if (!cmd) {
+    complete.log(Object.keys(commands), opts);
+    return done();
+  }
+
+  // if words[0] is a bower command, then complete on it.
+  cmd = commands[cmd];
+
+  if (cmd && cmd.completion) {
+    // prior to that, ensure the completion cache directory is created first
+    mkdirp(path.join(config.completion), function (err) {
+      if (err) return emitter.emit('error', err);
+      cmd.completion(opts, function (err, data) {
+        if (err) return emitter.emit('error', err);
+
+        // completing options, then append top level flags
+        if (opts.word.charAt(0) === '-') data = data.concat(flags);
+
+        complete.log(data, opts);
+
+        done();
+      });
+    });
+
+    return emitter;
+  }
+
+  // otherwise, do nothing
+  return emitter;
+};
+
+module.exports.line = function (argv) {
+  var emitter  = new Emitter;
+  var options  = nopt(optionTypes, shorthand, argv);
+
+  if (options.help) return help('completion');
+
+  module.exports(options.argv.remain.slice(2), process.env)
+    .on('data', emitter.emit.bind(emitter, 'data'))
+    .on('error', emitter.emit.bind(emitter, 'error'))
+    .on('end', emitter.emit.bind(emitter, 'end'));
+
+  return emitter;
+};

lib/commands/install.js

@@ -13,8 +13,12 @@
 
 var Emitter = require('events').EventEmitter;
 var nopt    = require('nopt');
+var fs      = require('fs');
+var path    = require('path');
 
 var Manager = require('../core/manager');
+var config  = require('../core/config');
+var source  = require('../core/source');
 var save    = require('../util/save');
 var help    = require('./help');
 
@@ -43,3 +47,36 @@ module.exports.line = function (argv) {
   if (options.help) return help('install');
   return module.exports(paths, options);
 };
+
+module.exports.completion = function (opts, cb) {
+  var word = opts.word;
+
+  // completing options?
+  if (opts.words[0] === 'install' && word.charAt(0) === '-') {
+    return cb(null, Object.keys(optionTypes).map(function (option) {
+      return '--' + option;
+    }));
+  }
+
+  var cache = path.join(config.completion, 'install.json');
+  var done = function done(err, results) {
+    if (err) return cb(err);
+    var names = results.map(function (pkg) {
+      return pkg.name;
+    });
+
+    return cb(null, names);
+  };
+
+  fs.readFile(cache, function (err, body) {
+    if (!err) return done(null, JSON.parse(body));
+
+    // expected error, do the first request and cache the results
+    source.all(function (err, results) {
+      if (err) return cb(err);
+      fs.writeFile(cache, JSON.stringify(results, null, 2), function (err) {
+        done(err, results);
+      });
+    });
+  });
+};

lib/core/config.js

@@ -26,6 +26,7 @@ var folder = process.platform === 'win32'
 var config = require('rc') ('bower', {
   cache      :  path.join(roaming, folder, 'cache'),
   links      :  path.join(roaming, folder, 'links'),
+  completion :  path.join(roaming, folder, 'completion'),
   json       : 'component.json',
   endpoint   : 'https://bower.herokuapp.com',
   directory  : 'components'
@@ -41,4 +42,4 @@ if (fileExists(localFile)) {
 // If an uncaught exception occurs, the temporary directories will be deleted nevertheless
 tmp.setGracefulCleanup();
 
-module.exports = config;
+module.exports = config;

lib/util/completion.js

@@ -0,0 +1,65 @@
+// ==========================================
+// BOWER: completion
+// ==========================================
+// Copyright 2012 Twitter, Inc
+// Licensed under The MIT License
+// http://opensource.org/licenses/MIT
+// ==========================================
+
+// This module exposes a simple helper to parse the environment variables in
+// case of a tab completion command. It parses the provided `argv` (nopt's
+// remain arguments after `--`) and `env` (should be process.env)
+//
+// It is inspired and based off Isaac's work on npm.
+
+module.exports = function (argv, env) {
+  var opts = {};
+
+  // w is the words number, based on the cursor position
+  opts.w = +env.COMP_CWORD;
+
+  // words is the escaped sequence of words following `bower`
+  opts.words = argv.map(function (word) {
+    return word.charAt(0) === "\"" ?
+      word.replace(/^"|"$/g, "") :
+      word.replace(/\\ /g, " ");
+  });
+
+  // word is a shortcut to the last word in the line
+  opts.word = opts.words[opts.w - 1];
+
+  // line is the sequence of tab completed words.
+  opts.line = env.COMP_LINE;
+
+  // point is the cursor position in the line
+  opts.point = +env.COMP_POINT;
+
+  // length is the whole line's length.
+  opts.length = opts.line.length;
+
+  // partialLine is the line ignoring the sequence of characters after
+  // cursor position, ie. tabbing at: bower install j|qu
+  // gives back a partialLine: bower install j
+  opts.partialLine = opts.line.slice(0, opts.point);
+
+  // partialWords is only returning the words based on cursor position,
+  // ie tabbing at: bower install ze|pto backbone
+  // gives back a partialWords array: ['install', 'zepto']
+  opts.partialWords = opts.words.slice(0, opts.w);
+
+  return opts;
+};
+
+module.exports.log = function (arr, opts, prefix) {
+  arr = Array.isArray(arr) ? arr : [arr];
+  arr.filter(module.exports.abbrev(opts)).forEach(function (word) {
+    console.log(word);
+  });
+};
+
+module.exports.abbrev = function abbrev(opts) {
+  var word = opts.word.replace(/\./g, '\\.');
+  return function (it) {
+    return new RegExp('^' + word).test(it);
+  };
+};