fix(es/minifier): Fix operand handling of ** (#8933)

**Related issue:** - Closes #8924
swc-project · May 8, 2024 · c9d72cd · c9d72cd
1 parent bd6873e
commit c9d72cd
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Showing 5 changed files with 88 additions and 12 deletions.
diff --git a/crates/swc_ecma_minifier/src/compress/optimize/evaluate.rs b/crates/swc_ecma_minifier/src/compress/optimize/evaluate.rs
@@ -354,12 +354,20 @@ impl Optimizer<'_> {
                         self.changed = true;
                         report_change!("evaluate: Evaluated `{:?} ** {:?}`", l, r);
 
-                        let value = l.powf(r);
-                        *e = Expr::Lit(Lit::Num(Number {
-                            span: bin.span,
-                            value,
-                            raw: None,
-                        }));
+                        if l.is_nan() || r.is_nan() {
+                            *e = Expr::Ident(Ident::new(
+                                "NaN".into(),
+                                bin.span.with_ctxt(
+                                    SyntaxContext::empty().apply_mark(self.marks.unresolved_mark),
+                                ),
+                            ));
+                        } else {
+                            *e = Expr::Lit(Lit::Num(Number {
+                                span: bin.span,
+                                value: l.powf(r),
+                                raw: None,
+                            }));
+                        };
                     }
                 }
             }

diff --git a/crates/swc_ecma_minifier/src/compress/optimize/sequences.rs b/crates/swc_ecma_minifier/src/compress/optimize/sequences.rs
@@ -1552,21 +1552,35 @@ impl Optimizer<'_> {
             }
         }
 
-        if match &*b {
+        match &*b {
             Expr::Arrow(..)
             | Expr::Fn(..)
             | Expr::Class(..)
             | Expr::Lit(..)
             | Expr::Await(..)
             | Expr::Yield(..)
             | Expr::Tpl(..)
-            | Expr::TaggedTpl(..) => true,
+            | Expr::TaggedTpl(..) => return Ok(false),
+
+            Expr::Assign(AssignExpr {
+                op: op!("**="),
+                right,
+                ..
+            })
+            | Expr::Bin(BinExpr {
+                op: op!("**"),
+                right,
+                ..
+            }) => {
+                if is_pure_undefined(&self.expr_ctx, right) {
+                    return Ok(false);
+                }
+            }
+
             Expr::Unary(UnaryExpr {
                 op: op!("delete"), ..
-            }) => true,
-            _ => false,
-        } {
-            return Ok(false);
+            }) => return Ok(false),
+            _ => {}
         }
 
         match a {

diff --git a/crates/swc_ecma_minifier/tests/fixture/issues/8924/config.json b/crates/swc_ecma_minifier/tests/fixture/issues/8924/config.json
@@ -0,0 +1,47 @@
+{
+    "defaults": true,
+    "arguments": false,
+    "arrows": true,
+    "booleans": true,
+    "booleans_as_integers": false,
+    "collapse_vars": true,
+    "comparisons": true,
+    "computed_props": true,
+    "conditionals": true,
+    "dead_code": true,
+    "directives": true,
+    "drop_console": false,
+    "drop_debugger": true,
+    "evaluate": true,
+    "expression": false,
+    "hoist_funs": false,
+    "hoist_props": true,
+    "hoist_vars": false,
+    "if_return": true,
+    "join_vars": true,
+    "keep_classnames": false,
+    "keep_fargs": true,
+    "keep_fnames": false,
+    "keep_infinity": false,
+    "loops": true,
+    "negate_iife": true,
+    "properties": true,
+    "reduce_funcs": false,
+    "reduce_vars": false,
+    "side_effects": true,
+    "switches": true,
+    "typeofs": true,
+    "unsafe": false,
+    "unsafe_arrows": false,
+    "unsafe_comps": false,
+    "unsafe_Function": false,
+    "unsafe_math": false,
+    "unsafe_symbols": false,
+    "unsafe_methods": false,
+    "unsafe_proto": false,
+    "unsafe_regexp": false,
+    "unsafe_undefined": false,
+    "unused": true,
+    "const_to_let": true,
+    "pristine_globals": true
+}
diff --git a/crates/swc_ecma_minifier/tests/fixture/issues/8924/input.js b/crates/swc_ecma_minifier/tests/fixture/issues/8924/input.js
@@ -0,0 +1,5 @@
+"use strict";
+const k = (() => {
+    let x = 1; x **= undefined;
+    return x;
+})();
diff --git a/crates/swc_ecma_minifier/tests/fixture/issues/8924/output.js b/crates/swc_ecma_minifier/tests/fixture/issues/8924/output.js
@@ -0,0 +1,2 @@
+"use strict";
+const k = NaN;