From be4609e54d2b246db45ae6417db9b93032b49b7e Mon Sep 17 00:00:00 2001
From: Shawn Erquhart <shawn@erquh.art>
Date: Wed, 4 Oct 2017 12:53:28 -0400
Subject: [PATCH] trim trailing whitespace from markdown

---
 .../serializers/__tests__/slate.spec.js       | 28 ++++++++-----------
 .../Widgets/Markdown/serializers/index.js     | 19 ++++++++-----
 2 files changed, 24 insertions(+), 23 deletions(-)

diff --git a/src/components/Widgets/Markdown/serializers/__tests__/slate.spec.js b/src/components/Widgets/Markdown/serializers/__tests__/slate.spec.js
index fd3bda41..28d78e77 100644
--- a/src/components/Widgets/Markdown/serializers/__tests__/slate.spec.js
+++ b/src/components/Widgets/Markdown/serializers/__tests__/slate.spec.js
@@ -4,37 +4,33 @@ import { markdownToSlate, slateToMarkdown } from '../index';
 const process = flow([markdownToSlate, slateToMarkdown]);
 
 describe('slate', () => {
-  it('should distinguish between newlines and hard breaks', () => {
-    expect(process('a\n')).toEqual('a\n');
-  });
-
   it('should not decode encoded html entities in inline code', () => {
-    expect(process('<code>&lt;div&gt;</code>')).toEqual('<code>&lt;div&gt;</code>\n');
+    expect(process('<code>&lt;div&gt;</code>')).toEqual('<code>&lt;div&gt;</code>');
   });
 
   it('should parse non-text children of mark nodes', () => {
-    expect(process('**a[b](c)d**')).toEqual('**a[b](c)d**\n');
-    expect(process('**[a](b)**')).toEqual('**[a](b)**\n');
-    expect(process('**![a](b)**')).toEqual('**![a](b)**\n');
-    expect(process('_`a`_')).toEqual('_`a`_\n');
-    expect(process('_`a`b_')).toEqual('_`a`b_\n');
+    expect(process('**a[b](c)d**')).toEqual('**a[b](c)d**');
+    expect(process('**[a](b)**')).toEqual('**[a](b)**');
+    expect(process('**![a](b)**')).toEqual('**![a](b)**');
+    expect(process('_`a`_')).toEqual('_`a`_');
+    expect(process('_`a`b_')).toEqual('_`a`b_');
   });
 
   it('should condense adjacent, identically styled text and inline nodes', () => {
-    expect(process('**a ~~b~~~~c~~**')).toEqual('**a ~~bc~~**\n');
-    expect(process('**a ~~b~~~~[c](d)~~**')).toEqual('**a ~~b[c](d)~~**\n');
+    expect(process('**a ~~b~~~~c~~**')).toEqual('**a ~~bc~~**');
+    expect(process('**a ~~b~~~~[c](d)~~**')).toEqual('**a ~~b[c](d)~~**');
   });
 
   it('should handle nested markdown entities', () => {
-    expect(process('**a**b**c**')).toEqual('**a**b**c**\n');
-    expect(process('**a _b_ c**')).toEqual('**a _b_ c**\n');
+    expect(process('**a**b**c**')).toEqual('**a**b**c**');
+    expect(process('**a _b_ c**')).toEqual('**a _b_ c**');
   });
 
   it('should parse inline images as images', () => {
-    expect(process('a ![b](c)')).toEqual('a ![b](c)\n');
+    expect(process('a ![b](c)')).toEqual('a ![b](c)');
   });
 
   it('should not escape markdown entities in html', () => {
-    expect(process('<span>*</span>')).toEqual('<span>*</span>\n');
+    expect(process('<span>*</span>')).toEqual('<span>*</span>');
   });
 });
diff --git a/src/components/Widgets/Markdown/serializers/index.js b/src/components/Widgets/Markdown/serializers/index.js
index 5b00150d..bc36b11a 100644
--- a/src/components/Widgets/Markdown/serializers/index.js
+++ b/src/components/Widgets/Markdown/serializers/index.js
@@ -1,4 +1,4 @@
-import { get, isEmpty, reduce, pull } from 'lodash';
+import { get, isEmpty, reduce, pull, trimEnd } from 'lodash';
 import unified from 'unified';
 import u from 'unist-builder';
 import markdownToRemarkPlugin from 'remark-parse';
@@ -118,17 +118,19 @@ export const remarkToMarkdown = obj => {
     fences: true,
     listItemIndent: '1',
 
-    // Settings to emulate the defaults from the Prosemirror editor, not
-    // necessarily optimal. Should eventually be configurable.
+    /**
+     * Settings to emulate the defaults from the Prosemirror editor, not
+     * necessarily optimal. Should eventually be configurable.
+     */
     bullet: '*',
     strong: '*',
     rule: '-',
   };
 
   /**
-   * Escape markdown entities found in text and html nodes within the MDAST.
+   * Transform the MDAST with plugins.
    */
-  const escapedMdast = unified()
+  const processedMdast = unified()
     .use(remarkEscapeMarkdownEntities)
     .use(remarkStripTrailingBreaks)
     .runSync(mdast);
@@ -136,9 +138,12 @@ export const remarkToMarkdown = obj => {
   const markdown = unified()
     .use(remarkToMarkdownPlugin, remarkToMarkdownPluginOpts)
     .use(remarkAllowAllText)
-    .stringify(escapedMdast);
+    .stringify(processedMdast);
 
-  return markdown;
+  /**
+   * Return markdown with trailing whitespace removed.
+   */
+  return trimEnd(markdown);
 };