feat: update lines-around-comment for class static blocks (#15323)

Updates the `lines-around-comment` rule so that options `"allowBlockStart"` and `"allowBlockEnd"` apply to class static blocks. Refs #15016
eslint · Nov 19, 2021 · f03cd14 · f03cd14
1 parent 5c64747
commit f03cd14
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diff --git a/docs/rules/lines-around-comment.md b/docs/rules/lines-around-comment.md
@@ -15,8 +15,8 @@ This rule has an object option:
 * `"afterBlockComment": true` requires an empty line after block comments
 * `"beforeLineComment": true` requires an empty line before line comments
 * `"afterLineComment": true` requires an empty line after line comments
-* `"allowBlockStart": true` allows comments to appear at the start of block statements
-* `"allowBlockEnd": true` allows comments to appear at the end of block statements
+* `"allowBlockStart": true` allows comments to appear at the start of block statements, function bodies, classes, and class static blocks
+* `"allowBlockEnd": true` allows comments to appear at the end of block statements, function bodies, classes, and class static blocks
 * `"allowObjectStart": true` allows comments to appear at the start of object literals
 * `"allowObjectEnd": true` allows comments to appear at the end of object literals
 * `"allowArrayStart": true` allows comments to appear at the start of array literals
@@ -133,6 +133,25 @@ function foo(){
     var day = "great"
     return day;
 }
+
+if (bar) {
+    // what a great and wonderful day
+    foo();
+}
+
+class C {
+    // what a great and wonderful day
+
+    method() {
+        // what a great and wonderful day
+        foo();
+    }
+
+    static {
+        // what a great and wonderful day
+        foo();
+    }
+}
 ```
 
 Examples of **correct** code for this rule with the `{ "beforeBlockComment": true, "allowBlockStart": true }` options:
@@ -145,6 +164,25 @@ function foo(){
     var day = "great"
     return day;
 }
+
+if (bar) {
+    /* what a great and wonderful day */
+    foo();
+}
+
+class C {
+    /* what a great and wonderful day */
+
+    method() {
+        /* what a great and wonderful day */
+        foo();
+    }
+
+    static {
+        /* what a great and wonderful day */
+        foo();
+    }
+}
 ```
 
 ### allowBlockEnd
@@ -159,6 +197,26 @@ function foo(){
     return day;
     // what a great and wonderful day
 }
+
+if (bar) {
+    foo();
+    // what a great and wonderful day
+}
+
+class C {
+
+    method() {
+        foo();
+        // what a great and wonderful day
+    }
+
+    static {
+        foo();
+        // what a great and wonderful day
+    }
+
+    // what a great and wonderful day
+}
 ```
 
 Examples of **correct** code for this rule with the `{ "afterBlockComment": true, "allowBlockEnd": true }` option:
@@ -172,6 +230,29 @@ function foo(){
 
     /* what a great and wonderful day */
 }
+
+if (bar) {
+    foo();
+
+    /* what a great and wonderful day */
+}
+
+class C {
+
+    method() {
+        foo();
+
+        /* what a great and wonderful day */
+    }
+
+    static {
+        foo();
+
+        /* what a great and wonderful day */
+    }
+
+    /* what a great and wonderful day */
+}
 ```
 
 ### allowClassStart

diff --git a/lib/rules/lines-around-comment.js b/lib/rules/lines-around-comment.js
@@ -185,10 +185,39 @@ module.exports = {
         /**
          * Returns the parent node that contains the given token.
          * @param {token} token The token to check.
-         * @returns {ASTNode} The parent node that contains the given token.
+         * @returns {ASTNode|null} The parent node that contains the given token.
          */
         function getParentNodeOfToken(token) {
-            return sourceCode.getNodeByRangeIndex(token.range[0]);
+            const node = sourceCode.getNodeByRangeIndex(token.range[0]);
+
+            /*
+             * For the purpose of this rule, the comment token is in a `StaticBlock` node only
+             * if it's inside the braces of that `StaticBlock` node.
+             *
+             * Example where this function returns `null`:
+             *
+             *   static
+             *   // comment
+             *   {
+             *   }
+             *
+             * Example where this function returns `StaticBlock` node:
+             *
+             *   static
+             *   {
+             *   // comment
+             *   }
+             *
+             */
+            if (node && node.type === "StaticBlock") {
+                const openingBrace = sourceCode.getFirstToken(node, { skip: 1 }); // skip the `static` token
+
+                return token.range[0] >= openingBrace.range[0]
+                    ? node
+                    : null;
+            }
+
+            return node;
         }
 
         /**
@@ -200,8 +229,15 @@ module.exports = {
         function isCommentAtParentStart(token, nodeType) {
             const parent = getParentNodeOfToken(token);
 
-            return parent && isParentNodeType(parent, nodeType) &&
-                    token.loc.start.line - parent.loc.start.line === 1;
+            if (parent && isParentNodeType(parent, nodeType)) {
+                const parentStartNodeOrToken = parent.type === "StaticBlock"
+                    ? sourceCode.getFirstToken(parent, { skip: 1 }) // opening brace of the static block
+                    : parent;
+
+                return token.loc.start.line - parentStartNodeOrToken.loc.start.line === 1;
+            }
+
+            return false;
         }
 
         /**
@@ -213,7 +249,7 @@ module.exports = {
         function isCommentAtParentEnd(token, nodeType) {
             const parent = getParentNodeOfToken(token);
 
-            return parent && isParentNodeType(parent, nodeType) &&
+            return !!parent && isParentNodeType(parent, nodeType) &&
                     parent.loc.end.line - token.loc.end.line === 1;
         }
 
@@ -223,7 +259,12 @@ module.exports = {
          * @returns {boolean} True if the comment is at block start.
          */
         function isCommentAtBlockStart(token) {
-            return isCommentAtParentStart(token, "ClassBody") || isCommentAtParentStart(token, "BlockStatement") || isCommentAtParentStart(token, "SwitchCase");
+            return (
+                isCommentAtParentStart(token, "ClassBody") ||
+                isCommentAtParentStart(token, "BlockStatement") ||
+                isCommentAtParentStart(token, "StaticBlock") ||
+                isCommentAtParentStart(token, "SwitchCase")
+            );
         }
 
         /**
@@ -232,7 +273,13 @@ module.exports = {
          * @returns {boolean} True if the comment is at block end.
          */
         function isCommentAtBlockEnd(token) {
-            return isCommentAtParentEnd(token, "ClassBody") || isCommentAtParentEnd(token, "BlockStatement") || isCommentAtParentEnd(token, "SwitchCase") || isCommentAtParentEnd(token, "SwitchStatement");
+            return (
+                isCommentAtParentEnd(token, "ClassBody") ||
+                isCommentAtParentEnd(token, "BlockStatement") ||
+                isCommentAtParentEnd(token, "StaticBlock") ||
+                isCommentAtParentEnd(token, "SwitchCase") ||
+                isCommentAtParentEnd(token, "SwitchStatement")
+            );
         }
 
         /**