feat: update block-spacing for class static blocks (#15297)

Updates the `block-spacing` rule to apply to class static blocks.

Refs #15016

docs/rules/block-spacing.md

@@ -23,6 +23,10 @@ if (foo) { bar = 0;}
 function baz() {let i = 0;
     return i;
 }
+
+class C {
+    static {this.bar = 0;}
+}
 ```
 
 Examples of **correct** code for this rule with the default `"always"` option:
@@ -32,6 +36,10 @@ Examples of **correct** code for this rule with the default `"always"` option:
 
 function foo() { return true; }
 if (foo) { bar = 0; }
+
+class C {
+    static { this.bar = 0; }
+}
 ```
 
 ### never
@@ -43,6 +51,10 @@ Examples of **incorrect** code for this rule with the `"never"` option:
 
 function foo() { return true; }
 if (foo) { bar = 0;}
+
+class C {
+    static { this.bar = 0; }
+}
 ```
 
 Examples of **correct** code for this rule with the `"never"` option:
@@ -52,6 +64,10 @@ Examples of **correct** code for this rule with the `"never"` option:
 
 function foo() {return true;}
 if (foo) {bar = 0;}
+
+class C {
+    static {this.bar = 0;}
+}
 ```
 
 ## When Not To Use It

lib/rules/block-spacing.js

@@ -40,7 +40,7 @@ module.exports = {
 
         /**
          * Gets the open brace token from a given node.
-         * @param {ASTNode} node A BlockStatement/SwitchStatement node to get.
+         * @param {ASTNode} node A BlockStatement/StaticBlock/SwitchStatement node to get.
          * @returns {Token} The token of the open brace.
          */
         function getOpenBrace(node) {
@@ -50,6 +50,12 @@ module.exports = {
                 }
                 return sourceCode.getLastToken(node, 1);
             }
+
+            if (node.type === "StaticBlock") {
+                return sourceCode.getFirstToken(node, { skip: 1 }); // skip the `static` token
+            }
+
+            // "BlockStatement"
             return sourceCode.getFirstToken(node);
         }
 
@@ -72,8 +78,8 @@ module.exports = {
         }
 
         /**
-         * Reports invalid spacing style inside braces.
-         * @param {ASTNode} node A BlockStatement/SwitchStatement node to get.
+         * Checks and reports invalid spacing style inside braces.
+         * @param {ASTNode} node A BlockStatement/StaticBlock/SwitchStatement node to check.
          * @returns {void}
          */
         function checkSpacingInsideBraces(node) {
@@ -157,6 +163,7 @@ module.exports = {
 
         return {
             BlockStatement: checkSpacingInsideBraces,
+            StaticBlock: checkSpacingInsideBraces,
             SwitchStatement: checkSpacingInsideBraces
         };
     }