biome style/noUselessElse

• Moving a `var`-declared variable from the `else` block to the outer scope may cause it to be hoisted and accessed before initialization if referenced earlier in the function.
• If the `else` block contains a `let` or `const` declaration that shadows an outer variable, promoting it may alter which binding inner functions capture due to changed scope nesting.
• Promoting statements from the `else` block may reorder their execution relative to other statements in the same block if the original `if-else` was not the first or last statement.
• If the `else` block contains a `break` targeting an outer loop, moving it outside the `if` may cause it to execute unconditionally, altering loop termination.
• A `continue` statement promoted from the `else` block may apply to a different loop than intended if loop nesting changes due to the removal of the `else` block's braces.
• A `throw` statement moved from the `else` block may be caught by a different `try`/`catch` if the `if-else` was inside a `try` block and the promotion changes the nesting level.
• Comments attached to the `else` keyword or its braces may be lost or misplaced during the rewrite, as the autofix typically does not preserve syntactic comments on removed tokens.
• If the `else` block is the sole content of a `case` clause in a `switch`, removing its braces may fall through to the next case if the promoted statements do not end with a `break`.
• In a `with` block, promoting `else` statements may change the object used for property resolution if the `if` and `else` blocks previously shared the same `with` context but the promotion alters evaluation order.
• If the `if` statement lacks braces and the autofix incorrectly assumes block structure, it may corrupt syntax by inserting or deleting braces where none existed.

--- orig.js	2026-10-17 16:58:19.058146079 -0400
+++ fixed.js	2026-10-17 16:58:19.349149963 -0400
@@ -1 +1 @@
-function f(a=0,b,c,d){if(arguments.length>2){return;}else{g();}}var x=0;function g(){x++};f(1,2);print(x);
+function f(a=0,b,c,d){if(arguments.length>2){return;}g();}var x=0;function g(){x++};f(1,2);print(x);

--- orig.js	2026-10-17 16:58:19.566152860 -0400
+++ fixed.js	2026-10-17 16:58:19.835156451 -0400
@@ -1 +1 @@
-let out='';function m(c){if(!c){return /*keep*/;}else/*start*/{out+=/*a*/'x'/*end*/;}/*after*/}m(false);m(true);print(out);
+let out='';function m(c){if(!c){return /*keep*/;}/*start*/out+=/*a*/'x'/*end*/;}m(false);m(true);print(out);

--- orig.js	2026-10-17 16:58:20.045159254 -0400
+++ fixed.js	2026-10-17 16:58:20.330163056 -0400
@@ -1 +1 @@
-async function* g(){if(1){return;}else{yield 2;}}const it=g();it.next().then(r=>out+=r.value?''+r.value:'');it.next().then(r=>out+=','+(r.done?'done':r.value));var out='';Promise.resolve().then(()=>print(out));
+async function* g(){if(1){return;}yield 2;}const it=g();it.next().then(r=>out+=r.value?''+r.value:'');it.next().then(r=>out+=','+(r.done?'done':r.value));var out='';Promise.resolve().then(()=>print(out));

--- orig.js	2026-10-17 16:58:20.486165137 -0400
+++ fixed.js	2026-10-17 16:58:20.738168499 -0400
@@ -1 +1 @@
-let s='';switch(1){case 1:if(0){break;}else{s+='a';}case 2:s+='b';break;}print(s);
+let s='';switch(1){case 1:if(0){break;}s+='a';case 2:s+='b';break;}print(s);

--- orig.js	2026-10-17 16:58:27.865263378 -0400
+++ fixed.js	2026-10-17 16:58:28.143267071 -0400
@@ -2,9 +2,8 @@
   console.log(x); // Hazard: x used before init
   if (false) {
     return;
-  } else {
-    var x = 1;
   }
+    var x = 1;
   return x;
 }
 f();

undefined

--- orig.js	2026-10-17 16:58:28.310269288 -0400
+++ fixed.js	2026-10-17 16:58:28.555272542 -0400
@@ -1,10 +1,9 @@
 function f() {
   if (true) {
     return; /* keep */
-  } else {
+  }
     // this comment should stay with g()
     g();
-  }
 }
 function g() { console.log('g'); }
 f();

--- orig.js	2026-10-17 16:58:28.711274614 -0400
+++ fixed.js	2026-10-17 16:58:28.986278266 -0400
@@ -3,9 +3,8 @@
   inner: for (let j = 0; j < 2; j++) {
     if (i === 0) {
       continue outer; /* else block */
-    } else {
-      out += j;
     }
+      out += j;
   }
 }
 console.log(out);

01

--- orig.js	2026-10-17 16:58:29.163280616 -0400
+++ fixed.js	2026-10-17 16:58:29.430284160 -0400
@@ -1,8 +1,7 @@
 function f() {
   if (false) {
     return;
-  } /* else */ else {
-    console.log('else ran');
   }
+    console.log('else ran');
 }
 f();

else ran

--- orig.js	2026-10-17 16:58:29.593286323 -0400
+++ fixed.js	2026-10-17 16:58:29.860289867 -0400
@@ -3,9 +3,8 @@
   log.push('start');
   if (false) {
     return;
-  } else {
-    log.push('else');
   }
+    log.push('else');
   log.push('end');
   return log.join(',');
 }

start,else,end

--- orig.js	2026-10-17 16:58:30.030292123 -0400
+++ fixed.js	2026-10-17 16:58:30.294295625 -0400
@@ -2,9 +2,8 @@
   for (let i = 0; i < 2; i++) {
     if (i === 0) {
       continue;
-    } else {
-      var x = i;
     }
+      var x = i;
     console.log(x); // Hazard: x from previous iteration
   }
 }

1

--- orig.js	2026-10-17 16:58:30.467297920 -0400
+++ fixed.js	2026-10-17 16:58:30.737301502 -0400
@@ -1,9 +1,8 @@
 function f(a, b = 0) {
   if (arguments.length === 0) {
     return;
-  } else {
-    b = arguments[0];
   }
+    b = arguments[0];
   return b;
 }
 console.log(f(5));

5

--- orig.js	2026-10-17 16:58:30.904303717 -0400
+++ fixed.js	2026-10-17 16:58:31.194307563 -0400
@@ -2,9 +2,8 @@
 outer: {
   if (false) {
     break outer;
-  } else {
-    log += 'a';
   }
+    log += 'a';
   log += 'b';
 }
 console.log(log);

ab