prefer-switch: Do not add braces to the default case

rules/prefer-switch.js

@@ -193,7 +193,17 @@ function fix({discriminant, ifStatements}, sourceCode, options) {
 		if (lastStatement.alternate) {
 			const {alternate} = lastStatement;
 			yield fixer.insertTextBefore(alternate, `\n${indent}default: `);
-			yield * insertBracesIfNotBlockStatement(alternate, fixer, indent);
+			/*
+			Technically, we should insert braces for the following case,
+			but who writes like this? And using `let`/`const` is invalid.
+
+			```js
+			if (foo === 1) {}
+			else if (foo === 2) {}
+			else if (foo === 3) {}
+			else var a = 1;
+			```
+			*/
 		} else {
 			switch (options.emptyDefaultCase) {
 				case 'no-default-comment':

test/snapshots/prefer-switch.mjs.md

@@ -96,10 +96,8 @@ Generated by [AVA](https://avajs.dev).
       11 | (notBlock())␊
       12 | break;␊
       13 | }␊
-      14 | default: {␊
-      15 | (notBlock())␊
-      16 | }␊
-      17 | }␊
+      14 | default: (notBlock())␊
+      15 | }␊
     `
 
 > Error 1/1
@@ -165,10 +163,8 @@ Generated by [AVA](https://avajs.dev).
        8 | case 3: {␊
        9 | break;␊
       10 | }␊
-      11 | default: {␊
-      12 | if (bar === 3) {}␊
-      13 | }␊
-      14 | }␊
+      11 | default: if (bar === 3) {}␊
+      12 | }␊
     `
 
 > Error 1/1
@@ -766,12 +762,10 @@ Generated by [AVA](https://avajs.dev).
        7 | 		foo++␊
        8 | 		break;␊
        9 | 		}␊
-      10 | 		default: {␊
-      11 | 		console.log('wow');␊
-      12 | 		}␊
-      13 | 		}␊
-      14 | 	})␊
-      15 | }␊
+      10 | 		default: console.log('wow');␊
+      11 | 		}␊
+      12 | 	})␊
+      13 | }␊
     `
 
 > Error 1/1
@@ -815,35 +809,31 @@ Generated by [AVA](https://avajs.dev).
        9 |  case 3: {␊
       10 |  break;␊
       11 |  }␊
-      12 |  default: {␊
-      13 |  if (two) {}␊
-      14 | else switch (bar) {␊
-      15 |  case 1: {␊
-      16 |  break;␊
-      17 |  }␊
-      18 |  case 2: {␊
-      19 |  break;␊
-      20 |  }␊
-      21 |  case 3: {␊
-      22 |  break;␊
-      23 |  }␊
-      24 |  default: {␊
-      25 |  switch (foo) {␊
-      26 |  case 1: {␊
-      27 |  break;␊
-      28 |  }␊
-      29 |  case 2: {␊
-      30 |  break;␊
-      31 |  }␊
-      32 |  case 3: {␊
-      33 |  break;␊
+      12 |  default: if (two) {}␊
+      13 | else switch (bar) {␊
+      14 |  case 1: {␊
+      15 |  break;␊
+      16 |  }␊
+      17 |  case 2: {␊
+      18 |  break;␊
+      19 |  }␊
+      20 |  case 3: {␊
+      21 |  break;␊
+      22 |  }␊
+      23 |  default: switch (foo) {␊
+      24 |  case 1: {␊
+      25 |  break;␊
+      26 |  }␊
+      27 |  case 2: {␊
+      28 |  break;␊
+      29 |  }␊
+      30 |  case 3: {␊
+      31 |  break;␊
+      32 |  }␊
+      33 |  // No default␊
       34 |  }␊
-      35 |  // No default␊
+      35 |  }␊
       36 |  }␊
-      37 |  }␊
-      38 |  }␊
-      39 |  }␊
-      40 |  }␊
     `
 
 > Error 1/3
@@ -1195,11 +1185,9 @@ Generated by [AVA](https://avajs.dev).
       59 | 	␊
       60 | 	break;␊
       61 | 	}␊
-      62 | 	default: {␊
-      63 | 	return 'default';␊
-      64 | 	}␊
-      65 | 	}␊
-      66 | }␊
+      62 | 	default: return 'default';␊
+      63 | 	}␊
+      64 | }␊
     `
 
 > Error 1/1