From 76005291ef09a0711b374a7592f54993bfb60ffb Mon Sep 17 00:00:00 2001
From: Ika <ikatyang@gmail.com>
Date: Wed, 7 Nov 2018 00:12:36 +0800
Subject: [PATCH 1/3] test: add tests

---
 tests/multiparser_js_html/__snapshots__/jsfmt.spec.js.snap | 6 ++++++
 tests/multiparser_js_html/lit-html.js                      | 2 ++
 2 files changed, 8 insertions(+)

diff --git a/tests/multiparser_js_html/__snapshots__/jsfmt.spec.js.snap b/tests/multiparser_js_html/__snapshots__/jsfmt.spec.js.snap
index 4f01fba7a1c2..bd878dce6be8 100644
--- a/tests/multiparser_js_html/__snapshots__/jsfmt.spec.js.snap
+++ b/tests/multiparser_js_html/__snapshots__/jsfmt.spec.js.snap
@@ -45,6 +45,8 @@ customElements.define('my-element', MyElement);
 
 const someHtml1 = html\`<div       > hello \${world} </div     >\`;
 const someHtml2 = /* HTML */ \`<div      > hello \${world} </div     >\`;
+
+html\`\`
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 import { LitElement, html } from "@polymer/lit-element";
 
@@ -82,4 +84,8 @@ const someHtml2 = /* HTML */ \`
   <div>hello \${world}</div>
 \`;
 
+html\`
+
+\`;
+
 `;
diff --git a/tests/multiparser_js_html/lit-html.js b/tests/multiparser_js_html/lit-html.js
index 1c432eaf0f2a..2b0ab038be3c 100644
--- a/tests/multiparser_js_html/lit-html.js
+++ b/tests/multiparser_js_html/lit-html.js
@@ -42,3 +42,5 @@ customElements.define('my-element', MyElement);
 
 const someHtml1 = html`<div       > hello ${world} </div     >`;
 const someHtml2 = /* HTML */ `<div      > hello ${world} </div     >`;
+
+html``

From bcb650303b5b1fca8f1325494a01718b17f502b6 Mon Sep 17 00:00:00 2001
From: Ika <ikatyang@gmail.com>
Date: Wed, 7 Nov 2018 00:12:57 +0800
Subject: [PATCH 2/3] fix(html-in-js): do not break empty content

---
 src/language-js/embed.js                           | 14 +++++++++++++-
 .../__snapshots__/jsfmt.spec.js.snap               |  4 +---
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/src/language-js/embed.js b/src/language-js/embed.js
index a47585906179..13e372c71618 100644
--- a/src/language-js/embed.js
+++ b/src/language-js/embed.js
@@ -626,7 +626,19 @@ function printHtmlTemplateLiteral(path, print, textToDoc, parser) {
     }
   );
 
-  return concat(["`", indent(concat([hardline, contentDoc])), softline, "`"]);
+  return group(
+    concat([
+      "`",
+      indent(
+        concat([
+          text.trim().length !== 0 ? hardline : softline,
+          group(contentDoc)
+        ])
+      ),
+      softline,
+      "`"
+    ])
+  );
 }
 
 module.exports = embed;
diff --git a/tests/multiparser_js_html/__snapshots__/jsfmt.spec.js.snap b/tests/multiparser_js_html/__snapshots__/jsfmt.spec.js.snap
index bd878dce6be8..1bf9d50f0800 100644
--- a/tests/multiparser_js_html/__snapshots__/jsfmt.spec.js.snap
+++ b/tests/multiparser_js_html/__snapshots__/jsfmt.spec.js.snap
@@ -84,8 +84,6 @@ const someHtml2 = /* HTML */ \`
   <div>hello \${world}</div>
 \`;
 
-html\`
-
-\`;
+html\`\`;
 
 `;

From 7d7fa1b8e614025cf416200de84d922b213a5d11 Mon Sep 17 00:00:00 2001
From: Ika <ikatyang@gmail.com>
Date: Wed, 7 Nov 2018 07:41:10 +0800
Subject: [PATCH 3/3] fix: never break empty content

---
 src/language-js/embed.js | 16 +++++-----------
 1 file changed, 5 insertions(+), 11 deletions(-)

diff --git a/src/language-js/embed.js b/src/language-js/embed.js
index 13e372c71618..a338e4c406a8 100644
--- a/src/language-js/embed.js
+++ b/src/language-js/embed.js
@@ -582,6 +582,10 @@ function printHtmlTemplateLiteral(path, print, textToDoc, parser) {
 
   const expressionDocs = path.map(print, "expressions");
 
+  if (expressionDocs.length === 0 && text.trim().length === 0) {
+    return "``";
+  }
+
   const contentDoc = mapDoc(
     stripTrailingHardline(textToDoc(text, { parser })),
     doc => {
@@ -627,17 +631,7 @@ function printHtmlTemplateLiteral(path, print, textToDoc, parser) {
   );
 
   return group(
-    concat([
-      "`",
-      indent(
-        concat([
-          text.trim().length !== 0 ? hardline : softline,
-          group(contentDoc)
-        ])
-      ),
-      softline,
-      "`"
-    ])
+    concat(["`", indent(concat([hardline, group(contentDoc)])), softline, "`"])
   );
 }