feat(transformer): do not transform ** with bigint literals (#6023)

part of #5822

They will produce runtime errors.

crates/oxc_ast/src/ast_impl/js.rs

@@ -103,6 +103,10 @@ impl<'a> Expression<'a> {
         matches!(self, Self::NumericLiteral(_) | Self::BigIntLiteral(_))
     }
 
+    pub fn is_big_int_literal(&self) -> bool {
+        matches!(self, Self::BigIntLiteral(_))
+    }
+
     pub fn is_specific_string_literal(&self, string: &str) -> bool {
         match self {
             Self::StringLiteral(s) => s.value == string,

crates/oxc_transformer/src/es2016/exponentiation_operator.rs

@@ -92,10 +92,14 @@ impl<'a> Traverse<'a> for ExponentiationOperator<'a> {
         }
     }
 
+    // NOTE: Bail bigint arguments to `Math.pow`, which are runtime errors.
     fn enter_expression(&mut self, expr: &mut Expression<'a>, ctx: &mut TraverseCtx<'a>) {
         // left ** right
         if let Expression::BinaryExpression(binary_expr) = expr {
             if binary_expr.operator == BinaryOperator::Exponential {
+                if binary_expr.left.is_big_int_literal() || binary_expr.right.is_big_int_literal() {
+                    return;
+                }
                 let left = ctx.ast.move_expression(&mut binary_expr.left);
                 let right = ctx.ast.move_expression(&mut binary_expr.right);
                 *expr = Self::math_pow(left, right, ctx);
@@ -105,6 +109,9 @@ impl<'a> Traverse<'a> for ExponentiationOperator<'a> {
         // left **= right
         if let Expression::AssignmentExpression(assign_expr) = expr {
             if assign_expr.operator == AssignmentOperator::Exponential {
+                if assign_expr.right.is_big_int_literal() {
+                    return;
+                }
                 let mut nodes = ctx.ast.vec();
                 let Some(Exploded { reference, uid }) =
                     self.explode(&mut assign_expr.left, &mut nodes, ctx)

tasks/transform_conformance/snapshots/oxc.snap.md

@@ -1,10 +1,11 @@
 commit: 3bcfee23
 
-Passed: 55/64
+Passed: 56/65
 
 # All Passed:
 * babel-plugin-transform-nullish-coalescing-operator
 * babel-plugin-transform-optional-catch-binding
+* babel-plugin-transform-exponentiation-operator
 * babel-plugin-transform-arrow-functions
 * babel-preset-typescript
 * babel-plugin-transform-react-jsx-source

tasks/transform_conformance/tests/babel-plugin-transform-exponentiation-operator/test/fixtures/bail-bigint/input.js

@@ -0,0 +1,8 @@
+a ** b; // transform
+a ** 1; // transform
+
+a ** 2n; // bail
+2n ** b; // bail
+2n ** 2n; // bail
+
+a **= 2n; // bail

tasks/transform_conformance/tests/babel-plugin-transform-exponentiation-operator/test/fixtures/bail-bigint/output.js

@@ -0,0 +1,8 @@
+Math.pow(a, b); // transform
+Math.pow(a, 1); // transform
+
+a ** 2n; // bail
+2n ** b; // bail
+2n ** 2n; // bail
+
+a **= 2n; // bail

tasks/transform_conformance/tests/babel-plugin-transform-exponentiation-operator/test/fixtures/options.json

@@ -0,0 +1,3 @@
+{
+  "plugins": ["transform-exponentiation-operator"]
+}