JavaScript: Keep line breaks when tagged template literal has a single line comment. (#6236)

CHANGELOG.unreleased.md

@@ -195,11 +195,33 @@ Previously, Prettier would incorrectly decode HTML entiites.
 </p>
 ```
 
+#### JavaScript: Stop moving comments inside tagged template literals ([#6236] by [@sosukesuzuki])
+
+Previously, Prettier would move comments after the tag inside the template literal. This version fixes this problem.
+
+<!-- prettier-ignore -->
+```js
+// Input
+foo //comment
+`
+`;
+
+// Output (Prettier stable)
+foo` // comment
+`;
+
+// Output (Prettier master)
+foo // comment
+`
+`;
+```
+
 [#6186]: https://github.com/prettier/prettier/pull/6186
 [#6206]: https://github.com/prettier/prettier/pull/6206
 [#6209]: https://github.com/prettier/prettier/pull/6209
 [#6217]: https://github.com/prettier/prettier/pull/6217
 [#6234]: https://github.com/prettier/prettier/pull/6234
+[#6236]: https://github.com/prettier/prettier/pull/6236
 [@duailibe]: https://github.com/duailibe
 [@gavinjoyce]: https://github.com/gavinjoyce
 [@sosukesuzuki]: https://github.com/sosukesuzuki

src/language-js/printer-estree.js

@@ -2406,7 +2406,7 @@ function printPathNoParens(path, options, print, args) {
         );
       }
 
-      parts.push("`");
+      parts.push(lineSuffixBoundary, "`");
 
       path.each(childPath => {
         const i = childPath.getName();
@@ -3914,6 +3914,7 @@ function printJestEachTemplateLiteral(node, expressions, options) {
       });
 
     parts.push(
+      lineSuffixBoundary,
       "`",
       indent(
         concat([

tests/comments/__snapshots__/jsfmt.spec.js.snap

@@ -2012,6 +2012,47 @@ switch (foo) {
 ================================================================================
 `;
 
+exports[`tagged-template-literal.js 1`] = `
+====================================options=====================================
+parsers: ["flow", "babel"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+foo\`\`; // comment
+
+foo // comment
+\`\`;
+
+foo // comment
+\`
+\`;
+
+foo /* comment */\`
+\`;
+
+foo /* comment */
+\`
+\`;
+
+=====================================output=====================================
+foo\`\`; // comment
+
+foo // comment
+\`\`;
+
+foo // comment
+\`
+\`;
+
+foo/* comment */ \`
+\`;
+
+foo /* comment */\`
+\`;
+
+================================================================================
+`;
+
 exports[`template-literal.js 1`] = `
 ====================================options=====================================
 parsers: ["flow", "babel"]

tests/comments/tagged-template-literal.js

@@ -0,0 +1,15 @@
+foo``; // comment
+
+foo // comment
+``;
+
+foo // comment
+`
+`;
+
+foo /* comment */`
+`;
+
+foo /* comment */
+`
+`;