fix(codegen): drop redundant space after else when minifying (#23025)

## What

Found with the whitespace analyzer (remove each space in minified output, check it still canonicalizes to the same AST). `print_body` printed an unconditional hard space before a single-statement body, so an `else` body kept a space even before non-identifier tokens:

| Input | Before | After |
| --- | --- | --- |
| ``if(x)a();else`t` `` | ``else `t` `` | ``else`t` `` |
| `if(x)a();else++b` | `else ++b` | `else++b` |
| `if(x)a();else[b]` | `else [b]` | `else[b]` |

esbuild emits these tight too.

## Fix

The body statement's first token already inserts a hard space via `print_space_before_identifier` whenever it would merge with a preceding identifier char — this is how `for`/`while`/`do` bodies (which pass `need_space=false`) already work; they're safe because they end in `)`. `else` ends in `e`, so the unconditional space was added as a blunt guard.

Removing it and relying on the body's own guard keeps the required spaces (`else x`, `else return 5`, `else debugger`, `else var k`, `else 5`) while dropping the unnecessary ones. The `need_space` parameter is now unused and removed.

Verified: every keyword-statement else-body (`return`/`throw`/`debugger`/`var`/…) self-guards; full codegen (116) + minifier (506) suites pass, and a 150-file real-world minify round-trip is idempotent.

crates/oxc_codegen/src/gen.rs

@@ -253,7 +253,7 @@ fn print_if(if_stmt: &IfStatement<'_>, p: &mut Codegen, ctx: Context) {
             }
         }
         stmt => {
-            p.print_body(stmt, false, ctx);
+            p.print_body(stmt, ctx);
             if if_stmt.alternate.is_some() {
                 p.print_indent();
             }
@@ -273,7 +273,7 @@ fn print_if(if_stmt: &IfStatement<'_>, p: &mut Codegen, ctx: Context) {
                 p.print_hard_space();
                 print_if(if_stmt, p, ctx);
             }
-            stmt => p.print_body(stmt, true, ctx),
+            stmt => p.print_body(stmt, ctx),
         }
     }
 }
@@ -338,7 +338,7 @@ impl Gen for ForStatement<'_> {
         }
 
         p.print_ascii_byte(b')');
-        p.print_body(&self.body, false, ctx);
+        p.print_body(&self.body, ctx);
     }
 }
 
@@ -358,7 +358,7 @@ impl Gen for ForInStatement<'_> {
         p.print_soft_space();
         p.print_expression(&self.right);
         p.print_ascii_byte(b')');
-        p.print_body(&self.body, false, ctx);
+        p.print_body(&self.body, ctx);
     }
 }
 
@@ -423,7 +423,7 @@ impl Gen for ForOfStatement<'_> {
         p.print_soft_space();
         self.right.print_expr(p, Precedence::Comma, Context::empty());
         p.print_ascii_byte(b')');
-        p.print_body(&self.body, false, ctx);
+        p.print_body(&self.body, ctx);
     }
 }
 
@@ -458,7 +458,7 @@ impl Gen for WhileStatement<'_> {
         p.print_ascii_byte(b'(');
         p.print_expression(&self.test);
         p.print_ascii_byte(b')');
-        p.print_body(&self.body, false, ctx);
+        p.print_body(&self.body, ctx);
     }
 }
 
@@ -576,7 +576,7 @@ impl Gen for SwitchCase<'_> {
         let single_line = self.consequent.len() == 1
             && !p.has_legal_orphans_before(self.consequent[0].span().start);
         if single_line {
-            p.print_body(&self.consequent[0], false, ctx);
+            p.print_body(&self.consequent[0], ctx);
             return;
         }
 
@@ -612,7 +612,7 @@ impl Gen for LabeledStatement<'_> {
         p.add_source_mapping(self.span);
         self.label.print(p, ctx);
         p.print_colon();
-        p.print_body(&self.body, false, ctx);
+        p.print_body(&self.body, ctx);
     }
 }
 
@@ -688,7 +688,7 @@ impl Gen for WithStatement<'_> {
         p.print_ascii_byte(b'(');
         p.print_expression(&self.object);
         p.print_ascii_byte(b')');
-        p.print_body(&self.body, false, ctx);
+        p.print_body(&self.body, ctx);
     }
 }
 

crates/oxc_codegen/src/lib.rs

@@ -630,7 +630,7 @@ impl<'a> Codegen<'a> {
         self.print_ascii_byte(b'}');
     }
 
-    fn print_body(&mut self, stmt: &Statement<'_>, need_space: bool, ctx: Context) {
+    fn print_body(&mut self, stmt: &Statement<'_>, ctx: Context) {
         match stmt {
             Statement::BlockStatement(stmt) => {
                 self.print_soft_space();
@@ -642,9 +642,10 @@ impl<'a> Codegen<'a> {
                 self.print_soft_newline();
             }
             stmt => {
-                if need_space && self.options.minify {
-                    self.print_hard_space();
-                }
+                // The statement's first token inserts a hard space itself (via
+                // `print_space_before_identifier`) when it would merge with a preceding
+                // identifier char (e.g. `else`), so `else{...}`/`else++x`/`else[0]` stay
+                // tight while `else x` keeps its space.
                 self.print_next_indent_as_space = true;
                 stmt.print(self, ctx);
             }

crates/oxc_codegen/tests/integration/js.rs

@@ -219,6 +219,12 @@ fn if_stmt() {
         "function f() { if (foo) return foo; else if (bar) return foo; }",
         "function f(){if(foo)return foo;else if(bar)return foo}",
     );
+    // `else` only needs a space before an identifier-like body.
+    test_minify("if(x)a();else b()", "if(x)a();else b();");
+    test_minify("if(x)a();else++b", "if(x)a();else++b;");
+    test_minify("if(x)a();else[b]", "if(x)a();else[b];");
+    test_minify("if(x)a();else`b`", "if(x)a();else`b`;");
+    test_minify("if(x)a();else debugger", "if(x)a();else debugger;");
 }
 
 #[test]

tasks/minsize/minsize.snap

@@ -7,21 +7,21 @@ Original   | minified   | minified   | gzip       | gzip       | Iterations | Fi
 
 287.63 kB  | 89.26 kB   | 90.07 kB   | 30.91 kB   | 31.95 kB   |          2 | jquery.js  
 
-342.15 kB  | 116.98 kB  | 118.14 kB  | 43.18 kB   | 44.37 kB   |          2 | vue.js     
+342.15 kB  | 116.97 kB  | 118.14 kB  | 43.18 kB   | 44.37 kB   |          2 | vue.js     
 
 544.10 kB  | 71.04 kB   | 72.48 kB   | 25.77 kB   | 26.20 kB   |          2 | lodash.js  
 
-555.77 kB  | 267.40 kB  | 270.13 kB  | 88.00 kB   | 90.80 kB   |          2 | d3.js      
+555.77 kB  | 267.40 kB  | 270.13 kB  | 88.01 kB   | 90.80 kB   |          2 | d3.js      
 
 1.01 MB    | 439.35 kB  | 458.89 kB  | 122.05 kB  | 126.71 kB  |          2 | bundle.min.js 
 
 1.25 MB    | 642.65 kB  | 646.76 kB  | 159.41 kB  | 163.73 kB  |          2 | three.js   
 
-2.14 MB    | 711.10 kB  | 724.14 kB  | 160.43 kB  | 181.07 kB  |          2 | victory.js 
+2.14 MB    | 711.10 kB  | 724.14 kB  | 160.44 kB  | 181.07 kB  |          2 | victory.js 
 
 3.20 MB    | 1.00 MB    | 1.01 MB    | 322.61 kB  | 331.56 kB  |          2 | echarts.js 
 
-6.69 MB    | 2.22 MB    | 2.31 MB    | 458.46 kB  | 488.28 kB  |          4 | antd.js    
+6.69 MB    | 2.22 MB    | 2.31 MB    | 458.45 kB  | 488.28 kB  |          4 | antd.js    
 
-10.95 MB   | 3.33 MB    | 3.49 MB    | 853.35 kB  | 915.50 kB  |          4 | typescript.js 
+10.95 MB   | 3.33 MB    | 3.49 MB    | 853.33 kB  | 915.50 kB  |          4 | typescript.js