CoffeeScript now supports ES2015 modules (#7818)

* Update CoffeeScript to 1.11.0, which supports modules; update check for whether to pass CoffeeScript’s output to Babel to look not just for backticks, but also for `import`, `export` and `function*`, the current ESNext features output by CoffeeScript

* Add tests for imported modules using CoffeeScript’s new native import statement

* Test that CoffeeScript native export statements work, by importing something exported by such a statement

* Improve regex

* Optimize regex

packages/coffeescript/package.js

@@ -8,7 +8,7 @@ Package.registerBuildPlugin({
   use: ['caching-compiler', 'ecmascript'],
   sources: ['plugin/compile-coffeescript.js'],
   npmDependencies: {
-    "coffee-script": "1.10.0",
+    "coffee-script": "1.11.0",
     "source-map": "0.5.6"
   }
 });
@@ -18,10 +18,10 @@ Package.onUse(function (api) {
   api.use('babel-compiler');
 
   // Because the CoffeeScript plugin now calls
-  // BabelCompiler.prototype.processOneFileForTarget for any raw
-  // JavaScript enclosed by backticks, it must provide the same runtime
-  // environment that the 'ecmascript' package provides. The following
-  // api.imply calls should match those in ../ecmascript/package.js,
+  // BabelCompiler.prototype.processOneFileForTarget for any ES2015+
+  // JavaScript or JavaScript enclosed by backticks, it must provide the
+  // same runtime environment that the 'ecmascript' package provides.
+  // The following api.imply calls should match those in ../ecmascript/package.js,
   // except that coffeescript does not api.imply('modules').
   api.imply('ecmascript-runtime');
   api.imply('babel-runtime');
@@ -37,6 +37,7 @@ Package.onTest(function (api) {
     'tests/coffeescript_test_setup.js',
     'tests/coffeescript_tests.coffee',
     'tests/coffeescript_strict_tests.coffee',
+    'tests/coffeescript_module.coffee',
     'tests/es2015_module.js',
     'tests/litcoffeescript_tests.litcoffee',
     'tests/litcoffeescript_tests.coffee.md',

packages/coffeescript/plugin/compile-coffeescript.js

@@ -83,8 +83,9 @@ export class CoffeeCompiler extends CachingCompiler {
 
     let sourceMap = JSON.parse(output.v3SourceMap);
 
-    if (source.indexOf('`') !== -1) {
-      // If source contains backticks, pass the coffee output through babel-compiler
+    if (source.match(/`|\b(?:import|export|yield)\b/)) {
+      // If source contains backticks or features that output as ES2015+,
+      // pass the coffee output through babel-compiler
       const doubleRoastedCoffee =
         this.babelCompiler.processOneFileForTarget(inputFile, output.js);
 

packages/coffeescript/tests/coffeescript_module.coffee

@@ -0,0 +1 @@
+export testingForNativeImportedModule123456789 = true

packages/coffeescript/tests/coffeescript_tests.coffee

@@ -7,10 +7,24 @@ Tinytest.add "coffeescript - compile", (test) -> test.isTrue true
 
 
 # import/export statements must be top-level
-`import { Meteor as testingForImportedSymbol123456789 } from "meteor/meteor";`
-Tinytest.add "coffeescript - import external package via backticks", (test) ->
-  test.isTrue testingForImportedSymbol123456789?
+`import { Meteor as testingForBacktickedImportedSymbol } from "meteor/meteor";`
+Tinytest.add "coffeescript - import external package via backticked import statement", (test) ->
+  test.isTrue testingForBacktickedImportedSymbol?
 
 `import { testingForImportedModule987654321 } from "./es2015_module.js";`
-Tinytest.add "coffeescript - import local module via backticks", (test) ->
+Tinytest.add "coffeescript - import local module via backticked import statement", (test) ->
   test.isTrue testingForImportedModule987654321?
+
+
+import { Meteor as testingForNativeImportedSymbol } from "meteor/meteor"
+Tinytest.add "coffeescript - import external package via native import statement", (test) ->
+  test.isTrue testingForNativeImportedSymbol?
+
+import { testingForImportedModule123456789 } from "./es2015_module.js";
+Tinytest.add "coffeescript - import local module via native import statement", (test) ->
+  test.isTrue testingForImportedModule123456789?
+
+
+import { testingForNativeImportedModule123456789 } from "./coffeescript_module.coffee";
+Tinytest.add "coffeescript - import local module exported by a CoffeeScript native export statement, via native import statement", (test) ->
+  test.isTrue testingForNativeImportedModule123456789?

packages/coffeescript/tests/es2015_module.js

@@ -1 +1,2 @@
+export const testingForImportedModule123456789 = true;
 export const testingForImportedModule987654321 = true;