refactor(minifier): clean up Normalize (#8700)

crates/oxc_minifier/src/ctx.rs

@@ -70,21 +70,6 @@ impl<'a> Ctx<'a, '_> {
         false
     }
 
-    #[inline]
-    pub fn is_identifier_infinity(self, ident: &IdentifierReference) -> bool {
-        if ident.name == "Infinity" && ident.is_global_reference(self.symbols()) {
-            return true;
-        }
-        false
-    }
-
-    #[inline]
-    pub fn is_identifier_nan(self, ident: &IdentifierReference) -> bool {
-        if ident.name == "NaN" && ident.is_global_reference(self.symbols()) {
-            return true;
-        }
-        false
-    }
     /// If two expressions are equal.
     /// Special case `undefined` == `void 0`
     pub fn expr_eq(self, a: &Expression<'a>, b: &Expression<'a>) -> bool {

crates/oxc_minifier/src/peephole/normalize.rs

@@ -1,6 +1,7 @@
 use oxc_allocator::Vec;
 use oxc_ast::ast::*;
 use oxc_ecmascript::constant_evaluation::ConstantEvaluation;
+use oxc_semantic::IsGlobalReference;
 use oxc_span::GetSpan;
 use oxc_syntax::scope::ScopeFlags;
 use oxc_traverse::{traverse_mut_with_ctx, Ancestor, ReusableTraverseCtx, Traverse, TraverseCtx};
@@ -62,23 +63,22 @@ impl<'a> Traverse<'a> for Normalize {
         if let Expression::ParenthesizedExpression(paren_expr) = expr {
             *expr = ctx.ast.move_expression(&mut paren_expr.expression);
         }
-        match expr {
-            Expression::Identifier(ident) => {
-                if let Some(e) = Self::try_compress_undefined(ident, ctx) {
-                    *expr = e;
-                }
-                Self::convert_infinity_or_nan_into_number(expr, ctx);
-            }
+        if let Some(e) = match expr {
+            Expression::Identifier(ident) => Self::try_compress_identifier(ident, ctx),
             Expression::UnaryExpression(e) if e.operator.is_void() => {
                 Self::convert_void_ident(e, ctx);
+                None
             }
             Expression::ArrowFunctionExpression(e) => {
                 self.recover_arrow_expression_after_drop_console(e);
+                None
             }
             Expression::CallExpression(_) if self.compress_options.drop_console => {
-                self.compress_console(expr, ctx);
+                self.compress_console(expr, ctx)
             }
-            _ => {}
+            _ => None,
+        } {
+            *expr = e;
         }
     }
 }
@@ -95,11 +95,13 @@ impl<'a> Normalize {
         matches!(stmt, Statement::DebuggerStatement(_)) && self.compress_options.drop_debugger
     }
 
-    fn compress_console(&mut self, expr: &mut Expression<'a>, ctx: &mut TraverseCtx<'a>) {
+    fn compress_console(
+        &mut self,
+        expr: &mut Expression<'a>,
+        ctx: &mut TraverseCtx<'a>,
+    ) -> Option<Expression<'a>> {
         debug_assert!(self.compress_options.drop_console);
-        if Self::is_console(expr) {
-            *expr = ctx.ast.void_0(expr.span());
-        }
+        Self::is_console(expr).then(|| ctx.ast.void_0(expr.span()))
     }
 
     fn drop_console(&mut self, stmt: &Statement<'a>) -> bool {
@@ -135,18 +137,34 @@ impl<'a> Normalize {
         *stmt = Statement::ForStatement(for_stmt);
     }
 
-    fn convert_infinity_or_nan_into_number(expr: &mut Expression<'a>, ctx: &mut TraverseCtx<'a>) {
-        if let Expression::Identifier(ident) = expr {
-            let ctx = Ctx(ctx);
-            let value = if ctx.is_identifier_infinity(ident) {
-                f64::INFINITY
-            } else if ctx.is_identifier_nan(ident) {
-                f64::NAN
-            } else {
-                return;
-            };
-            *expr =
-                ctx.ast.expression_numeric_literal(ident.span, value, None, NumberBase::Decimal);
+    /// Transforms `undefined` => `void 0`, `Infinity` => `f64::Infinity`, `NaN` -> `f64::NaN`.
+    /// So subsequent passes don't need to look up whether these variables are shadowed or not.
+    fn try_compress_identifier(
+        ident: &IdentifierReference<'a>,
+        ctx: &mut TraverseCtx<'a>,
+    ) -> Option<Expression<'a>> {
+        match ident.name.as_str() {
+            "undefined" if ident.is_global_reference(ctx.symbols()) => {
+                // `delete undefined` returns `false`
+                // `delete void 0` returns `true`
+                if matches!(ctx.parent(), Ancestor::UnaryExpressionArgument(e) if e.operator().is_delete())
+                {
+                    return None;
+                }
+                Some(ctx.ast.void_0(ident.span))
+            }
+            "Infinity" if ident.is_global_reference(ctx.symbols()) => {
+                Some(ctx.ast.expression_numeric_literal(
+                    ident.span,
+                    f64::INFINITY,
+                    None,
+                    NumberBase::Decimal,
+                ))
+            }
+            "NaN" if ident.is_global_reference(ctx.symbols()) => Some(
+                ctx.ast.expression_numeric_literal(ident.span, f64::NAN, None, NumberBase::Decimal),
+            ),
+            _ => None,
         }
     }
 
@@ -158,24 +176,6 @@ impl<'a> Normalize {
         }
         e.argument = ctx.ast.expression_numeric_literal(ident.span, 0.0, None, NumberBase::Decimal);
     }
-
-    /// Transforms `undefined` => `void 0`
-    /// So subsequent passes don't need to look up whether `undefined` is shadowed or not.
-    fn try_compress_undefined(
-        ident: &IdentifierReference<'a>,
-        ctx: &mut TraverseCtx<'a>,
-    ) -> Option<Expression<'a>> {
-        if !Ctx(ctx).is_identifier_undefined(ident) {
-            return None;
-        }
-        // `delete undefined` returns `false`
-        // `delete void 0` returns `true`
-        if matches!(ctx.parent(), Ancestor::UnaryExpressionArgument(e) if e.operator().is_delete())
-        {
-            return None;
-        }
-        Some(ctx.ast.void_0(ident.span))
-    }
 }
 
 #[cfg(test)]