Handle ContinueStatement and BreakStatement comments (#4279)

src/language-js/comments.js

@@ -135,7 +135,8 @@ function handleRemainingComment(comment, text, options, ast, isLastComment) {
       precedingNode,
       comment,
       options
-    )
+    ) ||
+    handleBreakAndContinueStatementComments(enclosingNode, comment)
   ) {
     return true;
   }
@@ -553,6 +554,19 @@ function handleLabeledStatementComments(enclosingNode, comment) {
   return false;
 }
 
+function handleBreakAndContinueStatementComments(enclosingNode, comment) {
+  if (
+    enclosingNode &&
+    (enclosingNode.type === "ContinueStatement" ||
+      enclosingNode.type === "BreakStatement") &&
+    !enclosingNode.label
+  ) {
+    addTrailingComment(enclosingNode, comment);
+    return true;
+  }
+  return false;
+}
+
 function handleCallExpressionComments(precedingNode, enclosingNode, comment) {
   if (
     enclosingNode &&

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

@@ -82,6 +82,33 @@ exports[`blank.js 1`] = `
 
 `;
 
+exports[`break-continue-statements.js 1`] = `
+for (;;) {
+  break /* comment */;
+  continue /* comment */;
+}
+
+loop: for (;;) {
+  break /* comment */ loop;
+  break loop /* comment */;
+  continue /* comment */ loop;
+  continue loop /* comment */;
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+for (;;) {
+  break; /* comment */
+  continue; /* comment */
+}
+
+loop: for (;;) {
+  break /* comment */ loop;
+  break loop /* comment */;
+  continue /* comment */ loop;
+  continue loop /* comment */;
+}
+
+`;
+
 exports[`call_comment.js 1`] = `
 render( // Warm any cache
   <ChildUpdates renderAnchor={true} anchorClassOn={true} />,

tests/comments/break-continue-statements.js

@@ -0,0 +1,11 @@
+for (;;) {
+  break /* comment */;
+  continue /* comment */;
+}
+
+loop: for (;;) {
+  break /* comment */ loop;
+  break loop /* comment */;
+  continue /* comment */ loop;
+  continue loop /* comment */;
+}