Fixed unstable while comment (#5251)

* Fixed unstable while comment

* Aligned while loop formatting more closely with if statment formatting

src/language-js/comments.js

@@ -28,6 +28,14 @@ function handleOwnLineComment(comment, text, options, ast, isLastComment) {
       comment,
       options
     ) ||
+    handleWhileComments(
+      text,
+      precedingNode,
+      enclosingNode,
+      followingNode,
+      comment,
+      options
+    ) ||
     handleTryStatementComments(
       enclosingNode,
       precedingNode,
@@ -93,6 +101,14 @@ function handleEndOfLineComment(comment, text, options, ast, isLastComment) {
       comment,
       options
     ) ||
+    handleWhileComments(
+      text,
+      precedingNode,
+      enclosingNode,
+      followingNode,
+      comment,
+      options
+    ) ||
     handleTryStatementComments(
       enclosingNode,
       precedingNode,
@@ -124,6 +140,14 @@ function handleRemainingComment(comment, text, options, ast, isLastComment) {
       comment,
       options
     ) ||
+    handleWhileComments(
+      text,
+      precedingNode,
+      enclosingNode,
+      followingNode,
+      comment,
+      options
+    ) ||
     handleObjectPropertyAssignment(enclosingNode, precedingNode, comment) ||
     handleCommentInEmptyParens(text, enclosingNode, comment, options) ||
     handleMethodNameComments(
@@ -246,11 +270,11 @@ function handleIfStatementComments(
   }
 
   // For comments positioned after the condition parenthesis in an if statement
-  // before the consequent with or without brackets on, such as
-  // if (a) /* comment */ {} or if (a) /* comment */ true,
-  // we look at the next character to see if it is a { or if the following node
+  // before the consequent without brackets on, such as
+  // if (a) /* comment */ true,
+  // we look at the next character to see if the following node
   // is the consequent for the if statement
-  if (nextCharacter === "{" || enclosingNode.consequent === followingNode) {
+  if (enclosingNode.consequent === followingNode) {
     addLeadingComment(followingNode, comment);
     return true;
   }
@@ -258,6 +282,45 @@ function handleIfStatementComments(
   return false;
 }
 
+function handleWhileComments(
+  text,
+  precedingNode,
+  enclosingNode,
+  followingNode,
+  comment,
+  options
+) {
+  if (
+    !enclosingNode ||
+    enclosingNode.type !== "WhileStatement" ||
+    !followingNode
+  ) {
+    return false;
+  }
+
+  // We unfortunately have no way using the AST or location of nodes to know
+  // if the comment is positioned before the condition parenthesis:
+  //   while (a /* comment */) {}
+  // The only workaround I found is to look at the next character to see if
+  // it is a ).
+  const nextCharacter = privateUtil.getNextNonSpaceNonCommentCharacter(
+    text,
+    comment,
+    options.locEnd
+  );
+  if (nextCharacter === ")") {
+    addTrailingComment(precedingNode, comment);
+    return true;
+  }
+
+  if (followingNode.type === "BlockStatement") {
+    addBlockStatementFirstComment(followingNode, comment);
+    return true;
+  }
+
+  return false;
+}
+
 // Same as IfStatement but for TryStatement
 function handleTryStatementComments(
   enclosingNode,

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

@@ -2062,3 +2062,51 @@ let // Comment
   bar = "val";
 
 `;
+
+exports[`while.js - flow-verify 1`] = `
+while(
+    true
+    // Comment
+  ) {}
+
+while(true)// Comment
+{}
+
+while(true){}// Comment
+
+while(true)/*Comment*/{}
+
+while(
+  true // Comment
+  && true // Comment
+  ){}
+
+while(true) {} // comment
+
+while(true) /* comment */ ++x; 
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+while (
+  true
+  // Comment
+) {}
+
+while (true) {
+  // Comment
+}
+
+while (true) {} // Comment
+
+while (true) {
+  /*Comment*/
+}
+
+while (
+  true && // Comment
+  true // Comment
+) {}
+
+while (true) {} // comment
+
+while (true) /* comment */ ++x;
+
+`;

tests/comments/while.js

@@ -0,0 +1,20 @@
+while(
+    true
+    // Comment
+  ) {}
+
+while(true)// Comment
+{}
+
+while(true){}// Comment
+
+while(true)/*Comment*/{}
+
+while(
+  true // Comment
+  && true // Comment
+  ){}
+
+while(true) {} // comment
+
+while(true) /* comment */ ++x;