From c1623d88e6a693d7fa4de2f511ef34f342bef2aa Mon Sep 17 00:00:00 2001
From: Ika <ikatyang@gmail.com>
Date: Sun, 3 Dec 2017 12:02:13 +0800
Subject: [PATCH] feat(markdown): preserve `break` style (#3325)

---
 src/doc-printer.js                                   |  7 ++++++-
 src/printer-markdown.js                              |  7 ++++++-
 .../markdown_break/__snapshots__/jsfmt.spec.js.snap  |  6 ++++++
 tests/markdown_break/simple.md                       |  3 +++
 tests/markdown_spec/__snapshots__/jsfmt.spec.js.snap | 12 ++++++------
 5 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/src/doc-printer.js b/src/doc-printer.js
index 2bbf63d1..5b2b8e4e 100644
--- a/src/doc-printer.js
+++ b/src/doc-printer.js
@@ -398,7 +398,12 @@ function printDocToString(doc, options) {
                     out.pop();
                   }
 
-                  if (out.length) {
+                  if (
+                    out.length &&
+                    (options.parser !== "markdown" ||
+                      // preserve markdown's `break` node (two trailing spaces)
+                      !/\S {2}$/.test(out[out.length - 1]))
+                  ) {
                     out[out.length - 1] = out[out.length - 1].replace(
                       /[^\S\n]*$/,
                       ""
diff --git a/src/printer-markdown.js b/src/printer-markdown.js
index eeca4d7b..13b211fe 100644
--- a/src/printer-markdown.js
+++ b/src/printer-markdown.js
@@ -315,7 +315,12 @@ function genericPrint(path, options, print) {
     case "tableCell":
       return printChildren(path, options, print);
     case "break":
-      return concat(["\\", hardline]);
+      return concat([
+        /\s/.test(options.originalText[node.position.start.offset])
+          ? "  "
+          : "\\",
+        hardline
+      ]);
     case "tableRow": // handled in "table"
     default:
       throw new Error(`Unknown markdown type ${JSON.stringify(node.type)}`);
diff --git a/tests/markdown_break/__snapshots__/jsfmt.spec.js.snap b/tests/markdown_break/__snapshots__/jsfmt.spec.js.snap
index 2318b036..d1492cb9 100644
--- a/tests/markdown_break/__snapshots__/jsfmt.spec.js.snap
+++ b/tests/markdown_break/__snapshots__/jsfmt.spec.js.snap
@@ -3,7 +3,13 @@
 exports[`simple.md 1`] = `
 123  
 456
+
+123\\
+456
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+123  
+456
+
 123\\
 456
 
diff --git a/tests/markdown_break/simple.md b/tests/markdown_break/simple.md
index 16bd8d22..e56f8d7c 100644
--- a/tests/markdown_break/simple.md
+++ b/tests/markdown_break/simple.md
@@ -1,2 +1,5 @@
 123  
 456
+
+123\
+456
diff --git a/tests/markdown_spec/__snapshots__/jsfmt.spec.js.snap b/tests/markdown_spec/__snapshots__/jsfmt.spec.js.snap
index 01d94deb..a81a1cab 100644
--- a/tests/markdown_spec/__snapshots__/jsfmt.spec.js.snap
+++ b/tests/markdown_spec/__snapshots__/jsfmt.spec.js.snap
@@ -903,7 +903,7 @@ exports[`example-85.md 1`] = `
 exports[`example-86.md 1`] = `
     foo  
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-    foo
+    foo  
 
 `;
 
@@ -2120,7 +2120,7 @@ exports[`example-186.md 1`] = `
 aaa     
 bbb     
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-aaa\\
+aaa  
 bbb
 
 `;
@@ -5772,7 +5772,7 @@ exports[`example-597.md 1`] = `
 foo  
 baz
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-foo\\
+foo  
 baz
 
 `;
@@ -5790,7 +5790,7 @@ exports[`example-599.md 1`] = `
 foo       
 baz
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-foo\\
+foo  
 baz
 
 `;
@@ -5799,7 +5799,7 @@ exports[`example-600.md 1`] = `
 foo  
      bar
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-foo\\
+foo  
  bar
 
 `;
@@ -5817,7 +5817,7 @@ exports[`example-602.md 1`] = `
 *foo  
 bar*
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-_foo\\
+_foo  
 bar_
 
 `;