Add Markdown support as an entry point (issue #2274)

packages/core/integration-tests/test/integration/markdown/index.md

@@ -0,0 +1,5 @@
+# heading1
+
+content content content
+
+[image](./100x100.png)

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

@@ -0,0 +1,33 @@
+const assert = require('assert');
+const path = require('path');
+const fs = require('@parcel/fs');
+const {bundle, run, assertBundleTree} = require('./utils');
+
+describe('markdown', function() {
+  it('should support bundling Markdown', async function() {
+    let b = await bundle(
+      path.join(__dirname, '/integration/markdown/index.md')
+    );
+
+    await assertBundleTree(b, {
+      name: 'index.html',
+      assets: ['index.md'],
+      childBundles: [
+        {
+          type: 'png',
+          assets: ['100x100.png'],
+          childBundles: []
+        }
+      ]
+    });
+
+    let files = await fs.readdir(path.join(__dirname, '/dist'));
+    let html = await fs.readFile(path.join(__dirname, '/dist/index.html'));
+    for (let file of files) {
+      let ext = file.match(/\.([0-9a-z]+)(?:[?#]|$)/i)[0];
+      if (file !== 'index.html' && ext !== '.map') {
+        assert(html.includes(file));
+      }
+    }
+  });
+});

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

@@ -51,6 +51,7 @@ class Parser {
 
     this.registerExtension('jade', './assets/PugAsset');
     this.registerExtension('pug', './assets/PugAsset');
+    this.registerExtension('md', './assets/MarkdownAsset');
 
     let extensions = options.extensions || {};
     for (let ext in extensions) {

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

@@ -49,7 +49,6 @@ class Pipeline {
 
     let inputType = path.extname(asset.name).slice(1);
     let generated = [];
-
     for (let rendition of this.iterateRenditions(asset)) {
       let {type, value} = rendition;
       if (typeof value !== 'string' || rendition.final) {

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

@@ -0,0 +1,15 @@
+const localRequire = require('../utils/localRequire');
+const Asset = require('../Asset');
+
+class MarkdownAsset extends Asset {
+  constructor(name, options) {
+    super(name, options);
+    this.type = 'html';
+    this.hmrPageReload = true;
+  }
+  async generate() {
+    let marked = await localRequire('marked', this.name);
+    return marked(this.contents);
+  }
+}
+module.exports = MarkdownAsset;