example: have yo-complete based on yeoman-environment and parse-help

examples/yo-complete/complete-generators.js

@@ -0,0 +1,89 @@
+const debug    = require('tabtab/lib/debug')('tabtab:yo:generators');
+const env      = require('yeoman-environment').createEnv();
+const { exec } = require('child_process');
+const parse    = require('parse-help');
+
+// Lookup installed generator in yeoman environment, respond completion results
+// with each generator.
+
+let npmroot = '';
+
+module.exports = complete;
+
+function complete(data, done) {
+  debug('Init completion', data);
+
+  if (npmroot) {
+    process.env.NODE_PATH = npmroot;
+    return lookup(data, done);
+  }
+
+
+  exec('npm root -g', (err, out) => {
+    if (err) return done(err);
+    process.env.NODE_PATH = npmroot = out.trim();
+    lookup(data, done);
+  });
+}
+
+function lookup(data, done) {
+  debug('Lookup with', process.env.NODE_PATH);
+
+  if (data.last !== 'yo' && !/^-/.test(data.last)) {
+    return completeGenerator(data, done);
+  }
+
+  env.lookup((err) => {
+    if (err) return done(err);
+    var meta = env.getGeneratorsMeta();
+    var results = Object.keys(meta).map(completionItem('yo'));
+    debug('yor', results);
+    done(null, results);
+  });
+}
+
+function completeGenerator(data, done) {
+  var last = data.last;
+
+  exec(`yo ${last} --help`, (err, out) => {
+    if (err) return done(err);
+    var help = parse(out);
+    var alias = [];
+    var results = Object.keys(help.flags).map((key) => {
+      var flag = help.flags[key];
+      if (flag.alias) alias.push(Object.assign({}, flag, { name: flag.alias }));
+      flag.name = key;
+      return flag;
+    }).map(completionItem(last, '--'));
+
+    // results = results.concat(Object.keys(help.aliases)).map(completionItem(last.replace(':', '_'), '\-'));
+    // results = results.concat(Object.keys(help.aliases)).map(completionItem('yo', '-'));
+    results = results.concat(alias.map(completionItem(last.replace(':', '_'), '-')));
+
+    // issue with `--help` that triggers help output of echo command in shell script :/
+    results = results.filter((r) => {
+      return r.name !== '--help' && r.name !== '-h';
+    });
+
+
+    debug('r', results, help, alias);
+    done(null, results);
+  });
+}
+
+function completionItem(desc, prefix) {
+  prefix = prefix || '';
+  return function(item) {
+    var name = (typeof item === 'string' ? item : item.name);
+    desc = typeof item !== 'string' && item.description ? item.description : desc;
+    desc = desc.replace(/^#\s*/g, '');
+    desc = desc.replace(/:/, '->');
+    desc = desc.replace(/'/, ' ');
+
+    debug('->', prefix, name, desc);
+    return {
+      name: prefix + name,
+      description: desc
+    };
+  }
+}