Add Kotlin asset support

packages/core/fs/package.json

@@ -20,7 +20,8 @@
     "prepublish": "yarn build"
   },
   "dependencies": {
+    "@parcel/utils": "^1.10.3",
     "mkdirp": "^0.5.1",
-    "@parcel/utils": "^1.10.3"
+    "rimraf": "^2.6.2"
   }
 }

packages/core/fs/src/fs.js

@@ -1,12 +1,14 @@
 const {promisify} = require('@parcel/utils');
 const fs = require('fs');
 const mkdirp = require('mkdirp');
+const rimraf = require('rimraf');
 
 exports.readFile = promisify(fs.readFile);
 exports.writeFile = promisify(fs.writeFile);
 exports.stat = promisify(fs.stat);
 exports.readdir = promisify(fs.readdir);
 exports.unlink = promisify(fs.unlink);
+exports.rimraf = promisify(rimraf);
 exports.realpath = async function(path) {
   const realpath = promisify(fs.realpath);
   try {

packages/core/integration-tests/package.json

@@ -13,12 +13,14 @@
   },
   "devDependencies": {
     "@babel/core": "^7.2.0",
+    "@jetbrains/kotlinc-js-api": "^1.2.12",
     "@parcel/fs": "^1.10.3",
     "@parcel/test-utils": "^1.10.3",
     "codecov": "^3.0.0",
     "command-exists": "^1.2.6",
     "graphql-tag": "^2.6.0",
     "json5": "^1.0.1",
+    "kotlin": "^1.3.11",
     "mocha": "^5.1.1",
     "mocha-junit-reporter": "^1.18.0",
     "mocha-multi-reporters": "^1.1.7",

packages/core/integration-tests/test/integration/kotlin/index.js

@@ -0,0 +1,3 @@
+var test = require('./test.kt');
+
+module.exports = test.sum(2, 3);

packages/core/integration-tests/test/integration/kotlin/test.kt

@@ -0,0 +1,4 @@
+@JsName("sum")
+fun sum(a: Int, b: Int): Int {
+  return a + b
+}

packages/core/integration-tests/test/kotlin.js

@@ -0,0 +1,16 @@
+const assert = require('assert');
+const {bundle, assertBundleTree, run} = require('./utils');
+
+describe('kotlin', function() {
+  it('should produce a basic kotlin bundle', async function() {
+    let b = await bundle(__dirname + '/integration/kotlin/index.js');
+
+    await assertBundleTree(b, {
+      type: 'js',
+      assets: ['test.kt', 'index.js', 'browser.js', 'kotlin.js']
+    });
+
+    let output = await run(b);
+    assert.equal(output, 5);
+  });
+});

packages/core/parcel-bundler/src/Parser.js

@@ -27,6 +27,7 @@ class Parser {
     this.registerExtension('toml', './assets/TOMLAsset');
     this.registerExtension('gql', './assets/GraphqlAsset');
     this.registerExtension('graphql', './assets/GraphqlAsset');
+    this.registerExtension('kt', './assets/KotlinAsset');
 
     this.registerExtension('css', './assets/CSSAsset');
     this.registerExtension('pcss', './assets/CSSAsset');

packages/core/parcel-bundler/src/assets/KotlinAsset.js

@@ -0,0 +1,63 @@
+const Asset = require('../Asset');
+const localRequire = require('../utils/localRequire');
+const path = require('path');
+const fs = require('@parcel/fs');
+const os = require('os');
+
+class KotlinAsset extends Asset {
+  constructor(name, options) {
+    super(name, options);
+    this.type = 'js';
+  }
+
+  async generate() {
+    // require kotlin
+    const kotlinCompiler = await localRequire(
+      '@jetbrains/kotlinc-js-api',
+      this.name
+    );
+
+    let id = Math.random()
+      .toString(36)
+      .slice(3);
+    let dir = path.join(os.tmpdir(), id);
+    let filename = path.join(dir, id + '.js');
+
+    await fs.mkdirp(dir);
+
+    await kotlinCompiler.compile({
+      output: filename,
+      sources: [this.name],
+      moduleKind: 'commonjs',
+      noStdlib: false,
+      metaInfo: true,
+      sourceMaps: this.options.sourceMaps
+    });
+
+    let source = await fs.readFile(filename, 'utf8');
+    let sourceMap;
+    if (this.options.sourceMaps) {
+      sourceMap = await fs.readFile(filename + '.map', 'utf8');
+
+      sourceMap = JSON.parse(sourceMap);
+      sourceMap.sources = [this.relativeName];
+      sourceMap.sourcesContent = [this.contents];
+
+      // remove source map url
+      source = source.substring(0, source.lastIndexOf('//# sourceMappingURL'));
+    }
+
+    // delete temp directory
+    await fs.rimraf(dir);
+
+    return [
+      {
+        type: 'js',
+        value: source,
+        sourceMap
+      }
+    ];
+  }
+}
+
+module.exports = KotlinAsset;