refactor(minifier): clean up try_compress_typeof_undefined (#12958)

Author: Boshen

crates/oxc_ast/src/ast_impl/js.rs

@@ -91,6 +91,7 @@ impl<'a> Expression<'a> {
     /// Returns `true` for [string literals](StringLiteral) matching the
     /// expected value. Note that [non-substitution template
     /// literals](TemplateLiteral) are not considered.
+    #[inline]
     pub fn is_specific_string_literal(&self, string: &str) -> bool {
         match self {
             Self::StringLiteral(s) => s.value == string,

crates/oxc_minifier/examples/minifier.rs

@@ -51,7 +51,7 @@ fn main() -> std::io::Result<()> {
     let mut allocator = Allocator::default();
     let ret = minify(&allocator, &source_text, source_type, source_map_path, mangle, nospace);
     let printed = ret.code;
-    println!("{printed}");
+    // println!("{printed}");
 
     if let Some(source_map) = ret.map {
         let result = source_map.to_json_string();

crates/oxc_minifier/src/peephole/substitute_alternate_syntax.rs

@@ -242,13 +242,10 @@ impl<'a> PeepholeOptimizations {
         expr: &mut BinaryExpression<'a>,
         ctx: &mut Ctx<'a, '_>,
     ) -> Option<Expression<'a>> {
-        let Expression::UnaryExpression(unary_expr) = &expr.left else { return None };
+        let Expression::UnaryExpression(unary_expr) = &mut expr.left else { return None };
         if !unary_expr.operator.is_typeof() {
             return None;
         }
-        if !expr.right.is_specific_string_literal("undefined") {
-            return None;
-        }
         let (new_eq_op, new_comp_op) = match expr.operator {
             BinaryOperator::Equality | BinaryOperator::StrictEquality => {
                 (BinaryOperator::StrictEquality, BinaryOperator::GreaterThan)
@@ -258,19 +255,22 @@ impl<'a> PeepholeOptimizations {
             }
             _ => return None,
         };
-        if let Expression::Identifier(ident) = &unary_expr.argument {
-            if ctx.is_global_reference(ident) {
-                let left = expr.left.take_in(ctx.ast);
-                let right = ctx.ast.expression_string_literal(expr.right.span(), "u", None);
-                return Some(ctx.ast.expression_binary(expr.span, left, new_comp_op, right));
-            }
+        if !expr.right.is_specific_string_literal("undefined") {
+            return None;
         }
-
-        let Expression::UnaryExpression(unary_expr) = expr.left.take_in(ctx.ast) else {
-            unreachable!()
-        };
-        let right = ctx.ast.void_0(expr.right.span());
-        Some(ctx.ast.expression_binary(expr.span, unary_expr.unbox().argument, new_eq_op, right))
+        if let Expression::Identifier(ident) = &unary_expr.argument
+            && ctx.is_global_reference(ident)
+        {
+            let left = expr.left.take_in(ctx.ast);
+            let right = ctx.ast.expression_string_literal(expr.right.span(), "u", None);
+            return Some(ctx.ast.expression_binary(expr.span, left, new_comp_op, right));
+        }
+        Some(ctx.ast.expression_binary(
+            expr.span,
+            unary_expr.take_in(ctx.ast).argument,
+            new_eq_op,
+            ctx.ast.void_0(expr.right.span()),
+        ))
     }
 
     /// Remove unary `+` if `ToNumber` conversion is done by the parent expression