Extract util.isBlockComment() helper (#1602)

* Add trailing space when changing template literal line comment to block

This was originally part of https://github.com/prettier/prettier/pull/1580,
but I decided not to include it there, since it was unrelated.

* Extract util.isBlockComment() helper

* printer: Simplify genericPrintNoParens() JSXEmptyExpression logic

* Extract makeBlockComment() helper

* Move hasBlockComments() from printer to util

Addresses https://github.com/prettier/prettier/pull/1602#issuecomment-301344310

* Revert "Extract makeBlockComment() helper"

This reverts commit 7e940f43b62fb34d71fc3015ed14f9c59cf61d1a.

* Revert "Add trailing space when changing template literal line comment to block"

This reverts commit b3cf5b24c576ed062ca86975a09138e3f4ac9597.

src/comments.js

@@ -728,8 +728,7 @@ function handleImportDeclarationComments(
     precedingNode &&
     enclosingNode &&
     enclosingNode.type === "ImportDeclaration" &&
-    comment.type !== "CommentBlock" &&
-    comment.type !== "Block"
+    !util.isBlockComment(comment)
   ) {
     addTrailingComment(precedingNode, comment);
     return true;
@@ -821,7 +820,7 @@ function getQuasiRange(expr) {
 function printLeadingComment(commentPath, print, options) {
   const comment = commentPath.getValue();
   const contents = printComment(commentPath);
-  const isBlock = comment.type === "Block" || comment.type === "CommentBlock";
+  const isBlock = util.isBlockComment(comment);
 
   // Leading block comments should see if they need to stay on the
   // same line or not.
@@ -838,7 +837,7 @@ function printLeadingComment(commentPath, print, options) {
 function printTrailingComment(commentPath, print, options) {
   const comment = commentPath.getValue();
   const contents = printComment(commentPath);
-  const isBlock = comment.type === "Block" || comment.type === "CommentBlock";
+  const isBlock = util.isBlockComment(comment);
 
   if (
     util.hasNewline(options.originalText, locStart(comment), {

src/printer.js

@@ -1542,9 +1542,7 @@ function genericPrintNoParens(path, options, print, args) {
     case "JSXText":
       throw new Error("JSXTest should be handled by JSXElement");
     case "JSXEmptyExpression":
-      const requiresHardline = n.comments && n.comments.some(
-        comment => comment.type === "Line" || comment.type === "CommentLine"
-      );
+      const requiresHardline = n.comments && !n.comments.every(util.isBlockComment);
 
       return concat([
         comments.printDanglingComments(
@@ -2856,7 +2854,7 @@ function canPrintParamsWithoutParens(node) {
     !node.rest &&
     node.params[0].type === "Identifier" &&
     !node.params[0].typeAnnotation &&
-    !hasBlockComments(node.params[0]) &&
+    !util.hasBlockComments(node.params[0]) &&
     !node.params[0].optional &&
     !node.predicate &&
     !node.returnType
@@ -4231,13 +4229,6 @@ function hasDanglingComments(node) {
     node.comments.some(comment => !comment.leading && !comment.trailing);
 }
 
-function hasBlockComments(node) {
-  return node.comments &&
-    node.comments.some(comment =>
-      comment.type === "Block" || comment.type === "CommentBlock"
-    );
-}
-
 function removeLines(doc) {
   // Force this doc into flat mode by statically converting all
   // lines into spaces (or soft lines into nothing). Hard lines

src/util.js

@@ -312,6 +312,14 @@ function getLeftMost(node) {
   }
 }
 
+function hasBlockComments(node) {
+  return node.comments && node.comments.some(isBlockComment);
+}
+
+function isBlockComment(comment) {
+  return comment.type === "Block" || comment.type === "CommentBlock";
+}
+
 module.exports = {
   getPrecedence,
   isExportDeclaration,
@@ -331,5 +339,7 @@ module.exports = {
   locEnd,
   setLocStart,
   setLocEnd,
-  startsWithNoLookaheadToken
+  startsWithNoLookaheadToken,
+  hasBlockComments,
+  isBlockComment
 };