Revert "chore: Switch from gulp to gts, TypeScript 2.6 (#173)" (#185)

This reverts commit cb9f380 so that
we can move it to a `next` branch and leave `master` releasable.

.clang-format

@@ -0,0 +1,3 @@
+Language:        JavaScript
+BasedOnStyle:    Google
+ColumnLimit:     80

.gitignore

@@ -1,11 +1,11 @@
 node_modules/*
-build/
+/lib/
+/test/
 types/
 .idea
 .vscode
 docs/
 npm-debug.log
 coverage
 *.js.map
-yarn-error.log
-**/*.js
+yarn-error.log

.travis.yml

@@ -4,8 +4,7 @@ language: node_js
 node_js:
   - "4"
   - "6"
-  - "8"
-  - "9"
+  - "7"
 
 script:
   - npm test

README.md

@@ -60,7 +60,7 @@ the following snippet should work.
 
 ```js
 var google = require('googleapis');
-var GoogleAuth = require('google-auth-library').GoogleAuth;
+var GoogleAuth = require('google-auth-library');
 
 var authFactory = new GoogleAuth();
 var dns = google.dns('v1');

gulpfile.js

@@ -0,0 +1,86 @@
+'use strict';
+
+require('source-map-support').install();
+
+const clangFormat = require('clang-format');
+const del = require('del');
+const format = require('gulp-clang-format');
+const gulp = require('gulp');
+const merge = require('merge2');
+const mocha = require('gulp-mocha');
+const sourcemaps = require('gulp-sourcemaps');
+const ts = require('gulp-typescript');
+const tslint = require('gulp-tslint');
+
+const outDir = 'build';
+const sources = ['ts/lib/**/*.ts'];
+const tests = ['ts/test/**/*.ts'];
+const allFiles = ['*.js'].concat(sources, tests);
+
+let exitOnError = true;
+function onError() {
+  if (exitOnError) {
+    process.exit(1);
+  }
+}
+
+gulp.task('test.check-format', () => {
+  return gulp.src(allFiles)
+      .pipe(format.checkFormat('file', clangFormat))
+      .on('warning', onError);
+});
+
+gulp.task('format', () => {
+  return gulp.src(allFiles, {base: '.'})
+      .pipe(format.format('file', clangFormat))
+      .pipe(gulp.dest('.'));
+});
+
+gulp.task('test.check-lint', () => {
+  return gulp.src(allFiles)
+      .pipe(tslint({formatter: 'verbose'}))
+      .pipe(tslint.report())
+      .on('warning', onError);
+});
+
+gulp.task('clean', () => {
+  return del([`${outDir}`]);
+});
+
+gulp.task('compile', () => {
+  const tsResult = gulp.src(sources)
+                       .pipe(sourcemaps.init())
+                       .pipe(ts.createProject('tsconfig.json')())
+                       .on('error', onError);
+  return merge([
+    tsResult.dts.pipe(gulp.dest(`${outDir}/definitions`)),
+    tsResult.js
+        .pipe(sourcemaps.write(
+            '.', {includeContent: false, sourceRoot: '../../src'}))
+        .pipe(gulp.dest(`${outDir}/src`)),
+    tsResult.js.pipe(gulp.dest(`${outDir}/src`))
+  ]);
+});
+
+gulp.task('test.compile', ['compile'], () => {
+  return gulp.src(tests, {base: '.'})
+      .pipe(sourcemaps.init())
+      .pipe(ts.createProject('tsconfig.json')())
+      .on('error', onError)
+      .pipe(sourcemaps.write('.', {includeContent: false, sourceRoot: '../..'}))
+      .pipe(gulp.dest(`${outDir}/`));
+});
+
+gulp.task('test.unit', ['test.compile'], () => {
+  return gulp.src([`${outDir}/test/**/*.js`]).pipe(mocha({verbose: true}));
+});
+
+gulp.task('watch', () => {
+  exitOnError = false;
+  gulp.start(['test.compile']);
+  // TODO: also run unit tests in a non-fatal way
+  return gulp.watch(allFiles, ['test.compile']);
+});
+
+gulp.task('test', ['test.unit', 'test.check-format', 'test.check-lint']);
+gulp.task('default', ['compile']);