From 0e7cb291dce196a7a0603de9b824b0d5bc0a5109 Mon Sep 17 00:00:00 2001
From: Kai Cataldo <kaicataldo@gmail.com>
Date: Thu, 24 Oct 2019 20:57:03 -0400
Subject: [PATCH] Handle blank lines in starred-block comments correctly

---
 lib/rules/multiline-comment-style.js       |  10 +-
 tests/lib/rules/multiline-comment-style.js | 106 +++++++++++++++++++++
 2 files changed, 112 insertions(+), 4 deletions(-)

diff --git a/lib/rules/multiline-comment-style.js b/lib/rules/multiline-comment-style.js
index bfb4b7fb448..5bea92ded7b 100644
--- a/lib/rules/multiline-comment-style.js
+++ b/lib/rules/multiline-comment-style.js
@@ -95,13 +95,15 @@ module.exports = {
          * @returns {string[]} An array of the processed lines.
          */
         function processStarredBlockComment(comment) {
-            const lines = comment.value.split(astUtils.LINEBREAK_MATCHER).map(line => line.replace(/^\s*$/u, ""));
+            const lines = comment.value.split(astUtils.LINEBREAK_MATCHER)
+                .filter((line, i, linesArr) => !(i === 0 || i === linesArr.length - 1))
+                .map(line => line.replace(/^\s*$/u, ""));
             const allLinesHaveLeadingSpace = lines
                 .map(line => line.replace(/\s*\*/u, ""))
                 .filter(line => line.trim().length)
                 .every(line => line.startsWith(" "));
 
-            return lines.map(line => line.replace(allLinesHaveLeadingSpace ? /\s*\* /u : /\s*\*/u, ""));
+            return lines.map(line => line.replace(allLinesHaveLeadingSpace ? /\s*\* ?/u : /\s*\*/u, ""));
         }
 
         /**
@@ -322,7 +324,7 @@ module.exports = {
                     },
                     messageId: "expectedLines",
                     fix(fixer) {
-                        return fixer.replaceText(firstComment, convertToSeparateLines(firstComment, commentLines.filter(line => line.length)));
+                        return fixer.replaceText(firstComment, convertToSeparateLines(firstComment, commentLines));
                     }
                 });
             },
@@ -361,7 +363,7 @@ module.exports = {
                         },
                         messageId: "expectedBareBlock",
                         fix(fixer) {
-                            return fixer.replaceText(firstComment, convertToBlock(firstComment, commentLines.filter(line => line.length)));
+                            return fixer.replaceText(firstComment, convertToBlock(firstComment, commentLines));
                         }
                     });
                 }
diff --git a/tests/lib/rules/multiline-comment-style.js b/tests/lib/rules/multiline-comment-style.js
index 9e9e71b10a4..b44ea0a05d5 100644
--- a/tests/lib/rules/multiline-comment-style.js
+++ b/tests/lib/rules/multiline-comment-style.js
@@ -937,6 +937,78 @@ ruleTester.run("multiline-comment-style", rule, {
                 { messageId: "expectedLines", line: 2 }
             ]
         },
+        {
+            code: `
+                /*
+                 *
+                 * {
+                 *     "foo": 1,
+                 *     "bar": 2
+                 * }
+                 *
+                 */
+            `,
+            output: `
+                //${" "}
+                // {
+                //     "foo": 1,
+                //     "bar": 2
+                // }
+                //${" "}
+            `,
+            options: ["separate-lines"],
+            errors: [
+                { messageId: "expectedLines", line: 2 }
+            ]
+        },
+        {
+            code: `
+                /*
+                 *
+                 * {
+                 *     "foo": 1,
+                 *     "bar": 2
+                 * }
+                 *
+                 */
+            `,
+            output: `
+                /*${" "}
+                   {
+                       "foo": 1,
+                       "bar": 2
+                   }
+                    */
+            `,
+            options: ["bare-block"],
+            errors: [
+                { messageId: "expectedBareBlock", line: 2 }
+            ]
+        },
+        {
+            code: `
+                /*
+                 *
+                 *{
+                 *    "foo": 1,
+                 *    "bar": 2
+                 *}
+                 *
+                 */
+            `,
+            output: `
+                /*${" "}
+                   {
+                       "foo": 1,
+                       "bar": 2
+                   }
+                    */
+            `,
+            options: ["bare-block"],
+            errors: [
+                { messageId: "expectedBareBlock", line: 2 }
+            ]
+        },
         {
             code: `
                 /*
@@ -1027,10 +1099,12 @@ ruleTester.run("multiline-comment-style", rule, {
                 */
             `,
             output: `
+                //${" "}
                 // {
                 //     "foo": 1,
                 //     "bar": 2
                 // }
+                //${" "}
             `,
             options: ["separate-lines"],
             errors: [
@@ -1054,6 +1128,38 @@ ruleTester.run("multiline-comment-style", rule, {
             errors: [
                 { messageId: "expectedLines", line: 2 }
             ]
+        },
+        {
+            code: `
+                /*
+                 * foo
+                 *
+                 * bar
+                 */
+            `,
+            output: `
+                // foo
+                //${" "}
+                // bar
+            `,
+            options: ["separate-lines"],
+            errors: [{ messageId: "expectedLines", line: 2 }]
+        },
+        {
+            code: `
+                /*
+                 * foo
+                 *${" "}
+                 * bar
+                 */
+            `,
+            output: `
+                // foo
+                //${" "}
+                // bar
+            `,
+            options: ["separate-lines"],
+            errors: [{ messageId: "expectedLines", line: 2 }]
         }
     ]
 });