Add testing capability in TypeScript (#282)

* Move deprecated mocha.opts to .mocharc.js

* Add typescript

* add ts-node

* Add and run dummy test in TypeScript

* Make the first TypeScript test meaningful

* Split the types of tests

* restore ToC

.mocharc.js

@@ -0,0 +1,8 @@
+"use strict";
+
+module.exports = {
+  recursive: true,
+  reporter: "spec",
+  require: 'ts-node/register',
+  ui: "bdd",
+};

CONTRIBUTING.md

@@ -165,6 +165,15 @@ Or:
 
 Failures in the linting process may fail our continuous integration builds.
 
+### TypeScript tests
+
+It's also possible to implement tests in TypeScript, primarily for the purpose of testing the TypeScript definitions.  To run these tests, use:
+
+    npm run test:ts
+
+Note: at this point ESLint is not ran against TypeScript tests.
+
+
 Thanks again for helping out!
 
 

gulpfile.js

@@ -7,7 +7,8 @@ var eslint = require('gulp-eslint');
 
 var files = {
     src: ['./lib/**/*.js'],
-    test: ['./test/**/*.spec.js', './*.js']
+    test: ['./test/**/*.spec.js', './*.js'],
+    testTs: ['./test/**/*.spec.ts']
 };
 
 gulp.task('lint', function () {
@@ -27,11 +28,21 @@ gulp.task('dot', function () {
 
 gulp.task('test', gulp.series('dot', 'lint'));
 
+gulp.task('test:ts', function () {
+    return gulp.src(files.testTs, {read: false})
+        .pipe(mocha({reporter: 'dot', require: 'ts-node/register'}));
+});
+
 gulp.task('spec', function () {
     return gulp.src(files.test, {read: false})
         .pipe(mocha({reporter: 'spec'}));
 });
 
+gulp.task('spec:ts', function () {
+    return gulp.src(files.testTs, {read: false})
+        .pipe(mocha({reporter: 'spec'}));
+});
+
 gulp.task('coverage', function (done) {
     gulp.src(files.src)
         .pipe(istanbul())