From afe7c29c9fecfbe75b3bbc420382d797aa35d699 Mon Sep 17 00:00:00 2001
From: Blaine Bublitz <blaine.bublitz@gmail.com>
Date: Tue, 2 Jun 2020 22:20:32 -0700
Subject: [PATCH] New: Support .mjs extension (closes #65)

---
 index.js                         |  3 ++
 mjs-stub.js                      |  1 +
 package.json                     |  3 +-
 test/fixtures/mjs/0/package.json |  1 +
 test/fixtures/mjs/0/test.mjs     |  9 +++++
 test/fixtures/mjs/1/package.json |  1 +
 test/fixtures/mjs/1/test.mjs     |  9 +++++
 test/index.js                    | 69 +++++++++++++++++++++++++++++++-
 8 files changed, 94 insertions(+), 2 deletions(-)
 create mode 100644 mjs-stub.js
 create mode 100644 test/fixtures/mjs/0/package.json
 create mode 100644 test/fixtures/mjs/0/test.mjs
 create mode 100644 test/fixtures/mjs/1/package.json
 create mode 100644 test/fixtures/mjs/1/test.mjs

diff --git a/index.js b/index.js
index 40de0dc..18b1276 100644
--- a/index.js
+++ b/index.js
@@ -2,6 +2,8 @@ var path = require('path');
 
 var endsInBabelJs = /\.babel\.[jt]s(x)$/;
 
+var mjsStub = path.join(__dirname, 'mjs-stub');
+
 function ignoreNonBabelAndNodeModules(file) {
   return !endsInBabelJs.test(file) &&
     path.relative(process.cwd(), file).split(path.sep).indexOf('node_modules') >= 0;
@@ -130,6 +132,7 @@ var extensions = {
   '.litcoffee': ['coffeescript/register', 'coffee-script/register', 'coffeescript', 'coffee-script'],
   '.liticed': 'iced-coffee-script/register',
   '.ls': ['livescript', 'LiveScript'],
+  '.mjs': mjsStub,
   '.node': null,
   '.toml': {
     module: 'toml-require',
diff --git a/mjs-stub.js b/mjs-stub.js
new file mode 100644
index 0000000..6a1af95
--- /dev/null
+++ b/mjs-stub.js
@@ -0,0 +1 @@
+require.extensions['.mjs'] = null;
diff --git a/package.json b/package.json
index 3ca9f32..a19af20 100644
--- a/package.json
+++ b/package.json
@@ -15,7 +15,8 @@
   "main": "index.js",
   "files": [
     "LICENSE",
-    "index.js"
+    "index.js",
+    "mjs-stub.js"
   ],
   "scripts": {
     "lint": "eslint .",
diff --git a/test/fixtures/mjs/0/package.json b/test/fixtures/mjs/0/package.json
new file mode 100644
index 0000000..0967ef4
--- /dev/null
+++ b/test/fixtures/mjs/0/package.json
@@ -0,0 +1 @@
+{}
diff --git a/test/fixtures/mjs/0/test.mjs b/test/fixtures/mjs/0/test.mjs
new file mode 100644
index 0000000..4389305
--- /dev/null
+++ b/test/fixtures/mjs/0/test.mjs
@@ -0,0 +1,9 @@
+export default {
+  data: {
+    trueKey: true,
+    falseKey: false,
+    subKey: {
+      subProp: 1
+    }
+  }
+};
diff --git a/test/fixtures/mjs/1/package.json b/test/fixtures/mjs/1/package.json
new file mode 100644
index 0000000..0967ef4
--- /dev/null
+++ b/test/fixtures/mjs/1/package.json
@@ -0,0 +1 @@
+{}
diff --git a/test/fixtures/mjs/1/test.mjs b/test/fixtures/mjs/1/test.mjs
new file mode 100644
index 0000000..09ad00b
--- /dev/null
+++ b/test/fixtures/mjs/1/test.mjs
@@ -0,0 +1,9 @@
+module.exports = {
+  data: {
+    trueKey: true,
+    falseKey: false,
+    subKey: {
+      subProp: 1
+    }
+  }
+};
diff --git a/test/index.js b/test/index.js
index d16f571..9308011 100644
--- a/test/index.js
+++ b/test/index.js
@@ -84,6 +84,11 @@ describe('interpret.extensions', function() {
       return attempts;
     }
 
+    // We will handle the .mjs tests separately
+    if (ext === '.mjs') {
+      return attempts;
+    }
+
     modules.forEach(function(mod, idx) {
       if (mod && typeof mod !== 'string') {
         mod = mod.module;
@@ -220,9 +225,71 @@ describe('interpret.extensions', function() {
           };
           expect(require(fixture)).toEqual(expected);
       }
-
       done();
     });
   });
 
+  it('does not error with the .mjs extension', function(done) {
+    var ext = '.mjs';
+    var fixture = './fixtures/' + ext.slice(1) + '/0/test' + ext;
+
+    var result = rechoir.prepare(extensions, fixture);
+
+    expect(Array.isArray(result)).toEqual(true);
+    expect(result[0].moduleName).toEqual(path.join(__dirname, '../mjs-stub'));
+    done();
+  });
+
+  it('the module can be loaded with import(), ignoring the loader', function() {
+    if (nodeVersion.major < 12) {
+      this.skip();
+    }
+
+    var ext = '.mjs';
+    var fixture = './fixtures/' + ext.slice(1) + '/0/test' + ext;
+
+    rechoir.prepare(extensions, fixture);
+
+    var expected = {
+      data: {
+        trueKey: true,
+        falseKey: false,
+        subKey: {
+          subProp: 1,
+        },
+      },
+    };
+
+    // This avoid SyntaxError when parsing on old node versions
+    var imprt = new Function('a', 'return import(a)');
+
+    return imprt(fixture)
+      .then(function(result) {
+        expect(result.default).toEqual(expected);
+      });
+  });
+
+  it('stubs .mjs extension with null on old node that do not care it', function(done) {
+    if (nodeVersion.major > 10) {
+      this.skip();
+    }
+
+    var ext = '.mjs';
+    var fixture = './fixtures/' + ext.slice(1) + '/1/test' + ext;
+
+    rechoir.prepare(extensions, fixture);
+
+    var expected = {
+      data: {
+        trueKey: true,
+        falseKey: false,
+        subKey: {
+          subProp: 1,
+        },
+      },
+    };
+    expect(require(fixture)).toEqual(expected);
+    done();
+  });
+
 });