feat: significantly improve CLI startup times (#42)

Move a few heavier modules from static imports to lazy `require()`s.
Also remove support for globally installed addons via yarn *and* npm.
If Yarn is detected, Denali will search Yarn for global addons, otherwise
it wills search npm, but not both. This lets Yarn users avoid the
delays that npm forces (because we need to shell out for `npm root`, which
eats 500ms).

We could make this behavior configurable in the future, once we have
a ~/.denali config file

lib/find-addons.ts

@@ -38,12 +38,7 @@ export default function findAddons(isLocal: boolean): AddonSummary[] {
     return finalizeAddons(addons);
   }
 
-  let npmRoot = execSync('npm root -g').toString().trim();
-  debug(`searching for addons globally in npm root: ${ npmRoot }`);
-  let addons = findPlugins(merge({
-    dir: npmRoot,
-    scanAllDirs: true
-  }, findOptions));
+  let addons;
 
   // Because yarn stores it's global modules separately, and doesn't yet support the `root` command,
   // we have to double check yarn's global installs for any denali addons. The easiest way of
@@ -52,13 +47,12 @@ export default function findAddons(isLocal: boolean): AddonSummary[] {
   // development of global addons (like denali itself)
   // TODO shell out to `yarn root` once yarnpkg/yarn#2388 is fixed
   if (commandExists('yarn')) {
-    let yarnGlobalInstalls = path.join(YarnConstants.GLOBAL_MODULE_DIRECTORY, 'node_modules');
+    let yarnGlobalInstalls = YarnConstants.GLOBAL_MODULE_DIRECTORY;
     debug(`searching for addons globally in yarn global installs: ${ yarnGlobalInstalls }`);
     if (fs.existsSync(yarnGlobalInstalls)) {
-      addons = addons.concat(findPlugins(merge({
-        dir: yarnGlobalInstalls,
-        scanAllDirs: true
-      }, findOptions)));
+      addons = findPlugins(merge({
+        dir: yarnGlobalInstalls
+      }, findOptions));
     } else {
       debug(`Tried to load globally installed addons from yarn, but ${ yarnGlobalInstalls } doesn't exist, skipping ...`);
     }
@@ -72,6 +66,13 @@ export default function findAddons(isLocal: boolean): AddonSummary[] {
     } else {
       debug(`Tried to load globally linked addons from yarn, but ${ yarnGlobalLinks } doesn't exist, skipping ...`);
     }
+  } else {
+    let npmRoot = execSync('npm root -g').toString().trim();
+    debug(`searching for addons globally in npm root: ${ npmRoot }`);
+    addons = findPlugins(merge({
+      dir: npmRoot,
+      scanAllDirs: true
+    }, findOptions));
   }
 
   return finalizeAddons(addons);

lib/project.ts

@@ -1,5 +1,5 @@
 import * as path from 'path';
-import { Tree, Builder as Broccoli, BuildResults } from 'broccoli';
+// import { Tree, Builder as Broccoli, BuildResults } from 'broccoli';
 import * as rimraf from 'rimraf';
 import printSlowNodes from 'broccoli-slow-trees';
 import { sync as copyDereferenceSync } from 'copy-dereference';
@@ -81,11 +81,12 @@ export default class Project {
   }
 
   // TODO build descriptions
-  async _build(tree: Tree, destDir: string): Promise<void> {
+  async _build(tree: any, destDir: string): Promise<void> {
     try {
       debug('building project');
       let timer = startTimer();
       spinner.start(`Building ...`);
+      const Broccoli = require('broccoli').Builder;
       let broccoli = new Broccoli(tree);
       let results = await broccoli.build();
       await this.finishBuild(results, destDir);
@@ -116,9 +117,10 @@ export default class Project {
   /**
    * Build the project and start watching the source files for changes, rebuilding when they occur
    */
-  async _watch(tree: Tree, options: WatchOptions = {}) {
+  async _watch(tree: any, options: WatchOptions = {}) {
     spinner.start(`Watching ...`);
     let timer = startTimer();
+      const Broccoli = require('broccoli').Builder;
     let broccoli = new Broccoli(tree);
     let watcher = new Watcher(broccoli, { beforeRebuild: options.beforeRebuild, interval: 100 });
     let destDir = options.destDir || path.join(this.dir, 'dist');
@@ -192,7 +194,7 @@ export default class Project {
    * After a build completes, this method cleans up the result. It copies the results out of tmp and
    * into the output directory, and kicks off any optional behaviors post-build.
    */
-  finishBuild(results: BuildResults, destDir: string) {
+  finishBuild(results: { directory: string, graph: any }, destDir: string) {
     debug(`copying broccoli build output to dist`);
     rimraf.sync(destDir);
     copyDereferenceSync(path.resolve(results.directory), destDir);