From 47e91926f1d9ed763ad11cbd39a9b9fbc1986b20 Mon Sep 17 00:00:00 2001
From: Ryan Delaney <rrdelaney@outlook.com>
Date: Thu, 21 Dec 2017 11:29:55 -0800
Subject: [PATCH] Add Reason asset type (#342)

* Add bsb-js dependency

* Add ReasonAsset type

* Actually add the Reason asset type

* Add OCaml file type, add integration test, remote unused imports

* use promisify for reading files

* Fix integration tests
---
 package.json                        |  1 +
 src/Parser.js                       |  2 ++
 src/assets/ReasonAsset.js           | 28 ++++++++++++++++++++++++++++
 test/integration/reason/index.js    |  5 +++++
 test/integration/reason/local.bs.js | 11 +++++++++++
 test/integration/reason/local.re    |  3 +++
 test/reason.js                      | 16 ++++++++++++++++
 7 files changed, 66 insertions(+)
 create mode 100644 src/assets/ReasonAsset.js
 create mode 100644 test/integration/reason/index.js
 create mode 100644 test/integration/reason/local.bs.js
 create mode 100644 test/integration/reason/local.re
 create mode 100644 test/reason.js

diff --git a/package.json b/package.json
index a833671c5cc..2a214410871 100644
--- a/package.json
+++ b/package.json
@@ -14,6 +14,7 @@
     "babylon": "^6.17.4",
     "babylon-walk": "^1.0.2",
     "browser-resolve": "^1.11.2",
+    "bsb-js": "^1.0.1",
     "chalk": "^2.1.0",
     "chokidar": "^1.7.0",
     "commander": "^2.11.0",
diff --git a/src/Parser.js b/src/Parser.js
index 6bc3624caee..92365e2299f 100644
--- a/src/Parser.js
+++ b/src/Parser.js
@@ -12,6 +12,8 @@ class Parser {
     this.registerExtension('es6', './assets/JSAsset');
     this.registerExtension('jsm', './assets/JSAsset');
     this.registerExtension('mjs', './assets/JSAsset');
+    this.registerExtension('ml', './assets/ReasonAsset');
+    this.registerExtension('re', './assets/ReasonAsset');
     this.registerExtension('ts', './assets/TypeScriptAsset');
     this.registerExtension('tsx', './assets/TypeScriptAsset');
     this.registerExtension('coffee', './assets/CoffeeScriptAsset');
diff --git a/src/assets/ReasonAsset.js b/src/assets/ReasonAsset.js
new file mode 100644
index 00000000000..ed9268e01fa
--- /dev/null
+++ b/src/assets/ReasonAsset.js
@@ -0,0 +1,28 @@
+const bsb = require('bsb-js');
+const fs = require('fs');
+const JSAsset = require('./JSAsset');
+const promisify = require('../utils/promisify');
+const readFile = promisify(fs.readFile);
+
+class ReasonAsset extends JSAsset {
+  async parse(code) {
+    // This runs BuckleScript - the Reason to JS compiler.
+    // Other Asset types use `localRequire` but the `bsb-js` package already
+    // does that internally. This should also take care of error handling in
+    // the Reason compilation process.
+    if (process.env.NODE_ENV !== 'test') {
+      await bsb.runBuild();
+    }
+
+    // This is a simplified use-case for Reason - it only loads the recommended
+    // BuckleScript configuration to simplify the file processing.
+    const outputFile = this.name.replace(/\.(re|ml)$/, '.bs.js');
+    const outputContent = await readFile(outputFile);
+    this.contents = outputContent.toString();
+
+    // After loading the compiled JS source, use the normal JS behavior.
+    return await super.parse(this.contents);
+  }
+}
+
+module.exports = ReasonAsset;
diff --git a/test/integration/reason/index.js b/test/integration/reason/index.js
new file mode 100644
index 00000000000..46547936019
--- /dev/null
+++ b/test/integration/reason/index.js
@@ -0,0 +1,5 @@
+var local = require('./local.re');
+
+module.exports = function () {
+  return local.a + local.b;
+};
diff --git a/test/integration/reason/local.bs.js b/test/integration/reason/local.bs.js
new file mode 100644
index 00000000000..486e372765e
--- /dev/null
+++ b/test/integration/reason/local.bs.js
@@ -0,0 +1,11 @@
+// Generated by BUCKLESCRIPT VERSION 1.9.2, PLEASE EDIT WITH CARE
+'use strict';
+
+
+var a = 1;
+
+var b = 2;
+
+exports.a = a;
+exports.b = b;
+/* No side effect */
diff --git a/test/integration/reason/local.re b/test/integration/reason/local.re
new file mode 100644
index 00000000000..8869258b8ad
--- /dev/null
+++ b/test/integration/reason/local.re
@@ -0,0 +1,3 @@
+let a = 1;
+
+let b = 2;
diff --git a/test/reason.js b/test/reason.js
new file mode 100644
index 00000000000..dfefa3e3698
--- /dev/null
+++ b/test/reason.js
@@ -0,0 +1,16 @@
+const assert = require('assert');
+const fs = require('fs');
+const {bundle, run, assertBundleTree} = require('./utils');
+
+describe('reason', function() {
+  it('should produce a bundle', async function() {
+    let b = await bundle(__dirname + '/integration/reason/index.js');
+
+    assert.equal(b.assets.size, 2);
+    assert.equal(b.childBundles.size, 0);
+
+    let output = run(b);
+    assert.equal(typeof output, 'function');
+    assert.equal(output(), 3);
+  });
+});