Fix ts:precompile

Author: tansongyang

lib/commands/precompile.js

@@ -2,6 +2,7 @@
 'use strict';
 
 const tmpdir = require('../utilities/tmpdir');
+const execa = require('execa');
 const fs = require('fs-extra');
 const path = require('path');
 const walkSync = require('walk-sync');
@@ -26,13 +27,20 @@ module.exports = Command.extend({
 
     // prettier-ignore
     let flags = [
+      '--outDir', outDir,
+      '--rootDir', project.root,
+      '--allowJs', 'false',
+      '--noEmit', 'false',
       '--declaration',
       '--sourceMap', 'false',
       '--inlineSourceMap', 'false',
       '--inlineSources', 'false',
     ];
 
-    return compile({ project, outDir, flags }).then(() => {
+    // Ensure the output directory is created even if no files are generated
+    mkdirp.sync(outDir);
+
+    return execa('tsc', flags).then(() => {
       let output = [];
       for (let declSource of walkSync(outDir, { globs: ['**/*.d.ts'] })) {
         if (this._shouldCopy(declSource)) {