feat(transformer/class-properties): transform super assignment expressions within static prop initializer (#7991)

Alternative of #7956 and #7959. Unlike the previous method, adapting duplicating the same logic rather than making the same logic transform function to be generic

crates/oxc_transformer/src/common/helper_loader.rs

@@ -159,6 +159,7 @@ pub enum Helper {
     ClassPrivateFieldLooseKey,
     ClassPrivateFieldLooseBase,
     SuperPropGet,
+    SuperPropSet,
 }
 
 impl Helper {
@@ -183,6 +184,7 @@ impl Helper {
             Self::ClassPrivateFieldLooseKey => "classPrivateFieldLooseKey",
             Self::ClassPrivateFieldLooseBase => "classPrivateFieldLooseBase",
             Self::SuperPropGet => "superPropGet",
+            Self::SuperPropSet => "superPropSet",
         }
     }
 }

crates/oxc_transformer/src/es2022/class_properties/private_field.rs

@@ -1608,7 +1608,7 @@ impl<'a, 'ctx> ClassProperties<'a, 'ctx> {
     /// * Anything else `foo()` -> `_foo = foo()`, `_foo`
     ///
     /// Returns 2 `Expression`s. The first must be inserted into output first.
-    fn duplicate_object(
+    pub(super) fn duplicate_object(
         &self,
         object: Expression<'a>,
         ctx: &mut TraverseCtx<'a>,

crates/oxc_transformer/src/es2022/class_properties/static_prop_init.rs

@@ -195,9 +195,15 @@ impl<'a, 'ctx, 'v> VisitMut<'a> for StaticInitializerVisitor<'a, 'ctx, 'v> {
                 self.transform_call_expression_if_super_member_expression(call_expr);
                 self.class_properties.transform_call_expression(expr, self.ctx);
             }
+            // `super.prop = value`, `super.prop += value`, `super.prop ??= value` or
             // `object.#prop = value`, `object.#prop += value`, `object.#prop ??= value` etc
             Expression::AssignmentExpression(_) => {
-                self.class_properties.transform_assignment_expression(expr, self.ctx);
+                self.transform_assignment_expression_if_super_member_assignment_target(expr);
+                // Check again if it's an assignment expression, because it could have been transformed
+                // to other expression.
+                if matches!(expr, Expression::AssignmentExpression(_)) {
+                    self.class_properties.transform_assignment_expression(expr, self.ctx);
+                }
             }
             // `object.#prop++`, `--object.#prop`
             Expression::UpdateExpression(_) => {
@@ -521,4 +527,14 @@ impl<'a, 'ctx, 'v> StaticInitializerVisitor<'a, 'ctx, 'v> {
                 .transform_call_expression_for_super_member_expr(call_expr, self.ctx);
         }
     }
+
+    fn transform_assignment_expression_if_super_member_assignment_target(
+        &mut self,
+        expr: &mut Expression<'a>,
+    ) {
+        if self.this_depth == 0 {
+            self.class_properties
+                .transform_assignment_expression_for_super_assignment_target(expr, self.ctx);
+        }
+    }
 }

crates/oxc_transformer/src/es2022/class_properties/supers.rs

@@ -125,6 +125,152 @@ impl<'a, 'ctx> ClassProperties<'a, 'ctx> {
         arguments.push(Argument::from(array));
     }
 
+    /// Transform assignment expression where the left-hand side is a member expression with `super`.
+    ///
+    /// * `super.prop = value`
+    ///   -> `_superPropSet(_Class, "prop", value, _Class, 1)`
+    /// * `super.prop += value`
+    ///   -> `_superPropSet(_Class, "prop", _superPropGet(_Class, "prop", _Class) + value, _Class, 1)`
+    /// * `super.prop &&= value`
+    ///   -> `_superPropGet(_Class, "prop", _Class) && _superPropSet(_Class, "prop", value, _Class, 1)`
+    ///
+    /// * `super[prop] = value`
+    ///   -> `_superPropSet(_Class, prop, value, _Class, 1)`
+    /// * `super[prop] += value`
+    ///   -> `_superPropSet(_Class, prop, _superPropGet(_Class, prop, _Class) + value, _Class, 1)`
+    /// * `super[prop] &&= value`
+    ///   -> `_superPropGet(_Class, prop, _Class) && _superPropSet(_Class, prop, value, _Class, 1)`
+    //
+    // `#[inline]` so can bail out fast without a function call if `left` is not a member expression
+    // with `super` as member expression object (fairly rare).
+    // Actual transform is broken out into separate functions.
+    pub(super) fn transform_assignment_expression_for_super_assignment_target(
+        &mut self,
+        expr: &mut Expression<'a>,
+        ctx: &mut TraverseCtx<'a>,
+    ) {
+        let Expression::AssignmentExpression(assign_expr) = expr else { unreachable!() };
+        match &assign_expr.left {
+            AssignmentTarget::StaticMemberExpression(member) if member.object.is_super() => {
+                self.transform_assignment_expression_for_super_static_member_expr(expr, ctx);
+            }
+            AssignmentTarget::ComputedMemberExpression(member) if member.object.is_super() => {
+                self.transform_assignment_expression_for_super_computed_member_expr(expr, ctx);
+            }
+            _ => {}
+        };
+    }
+
+    /// Transform assignment expression where the left-hand side is a static member expression
+    /// with `super`.
+    ///
+    /// * `super.prop = value`
+    ///   -> `_superPropSet(_Class, "prop", value, _Class, 1)`
+    /// * `super.prop += value`
+    ///   -> `_superPropSet(_Class, "prop", _superPropGet(_Class, "prop", _Class) + value, _Class, 1)`
+    /// * `super.prop &&= value`
+    ///   -> `_superPropGet(_Class, "prop", _Class) && _superPropSet(_Class, "prop", value, _Class, 1)`
+    //
+    // `#[inline]` so that compiler sees that `expr` is an `Expression::AssignmentExpression`.
+    #[inline]
+    fn transform_assignment_expression_for_super_static_member_expr(
+        &mut self,
+        expr: &mut Expression<'a>,
+        ctx: &mut TraverseCtx<'a>,
+    ) {
+        let Expression::AssignmentExpression(assign_expr) = ctx.ast.move_expression(expr) else {
+            unreachable!()
+        };
+        let AssignmentExpression { span, operator, right: value, left } = assign_expr.unbox();
+        let AssignmentTarget::StaticMemberExpression(member) = left else { unreachable!() };
+        let property = ctx.ast.expression_string_literal(
+            member.property.span,
+            member.property.name.clone(),
+            None,
+        );
+        *expr =
+            self.transform_super_assignment_expression_impl(span, operator, property, value, ctx);
+    }
+
+    /// Transform assignment expression where the left-hand side is a computed member expression
+    /// with `super` as member expr object.
+    ///
+    /// * `super[prop] = value`
+    ///   -> `_superPropSet(_Class, prop, value, _Class, 1)`
+    /// * `super[prop] += value`
+    ///   -> `_superPropSet(_Class, prop, _superPropGet(_Class, prop, _Class) + value, _Class, 1)`
+    /// * `super[prop] &&= value`
+    ///   -> `_superPropGet(_Class, prop, _Class) && _superPropSet(_Class, prop, value, _Class, 1)`
+    ///
+    // `#[inline]` so that compiler sees that `expr` is an `Expression::AssignmentExpression`.
+    #[inline]
+    fn transform_assignment_expression_for_super_computed_member_expr(
+        &mut self,
+        expr: &mut Expression<'a>,
+        ctx: &mut TraverseCtx<'a>,
+    ) {
+        let Expression::AssignmentExpression(assign_expr) = ctx.ast.move_expression(expr) else {
+            unreachable!()
+        };
+        let AssignmentExpression { span, operator, right: value, left } = assign_expr.unbox();
+        let AssignmentTarget::ComputedMemberExpression(member) = left else { unreachable!() };
+        let property = member.unbox().expression;
+        *expr =
+            self.transform_super_assignment_expression_impl(span, operator, property, value, ctx);
+    }
+
+    /// Transform assignment expression where the left-hand side is a member expression with `super`
+    /// as member expr object.
+    ///
+    /// * `=` -> `_superPropSet(_Class, <prop>, <value>, _Class, 1)`
+    /// * `+=` -> `_superPropSet(_Class, <prop>, _superPropGet(_Class, <prop>, _Class) + <value>, 1)`
+    /// * `&&=` -> `_superPropGet(_Class, <prop>, _Class) && _superPropSet(_Class, <prop>, <value>, _Class, 1)`
+    fn transform_super_assignment_expression_impl(
+        &mut self,
+        span: Span,
+        operator: AssignmentOperator,
+        property: Expression<'a>,
+        value: Expression<'a>,
+        ctx: &mut TraverseCtx<'a>,
+    ) -> Expression<'a> {
+        if operator == AssignmentOperator::Assign {
+            // `super[prop] = value` -> `_superPropSet(_Class, prop, value, _Class, 1)`
+            self.create_super_prop_set(span, property, value, ctx)
+        } else {
+            // Make 2 copies of `object`
+            let (property1, property2) = self.duplicate_object(property, ctx);
+
+            if let Some(operator) = operator.to_binary_operator() {
+                // `super[prop] += value`
+                // -> `_superPropSet(_Class, prop, _superPropGet(_Class, prop, _Class) + value, _Class, 1)`
+
+                // `_superPropGet(_Class, prop, _Class)`
+                let get_call = self.create_super_prop_get(SPAN, property2, false, ctx);
+
+                // `_superPropGet(_Class, prop, _Class) + value`
+                let value = ctx.ast.expression_binary(SPAN, get_call, operator, value);
+
+                // `_superPropSet(_Class, prop, _superPropGet(_Class, prop, _Class) + value, 1)`
+                self.create_super_prop_set(span, property1, value, ctx)
+            } else if let Some(operator) = operator.to_logical_operator() {
+                // `super[prop] &&= value`
+                // -> `_superPropGet(_Class, prop, _Class) && _superPropSet(_Class, prop, value, _Class, 1)`
+
+                // `_superPropGet(_Class, prop, _Class)`
+                let get_call = self.create_super_prop_get(SPAN, property1, false, ctx);
+
+                // `_superPropSet(_Class, prop, value, _Class, 1)`
+                let set_call = self.create_super_prop_set(span, property2, value, ctx);
+
+                // `_superPropGet(_Class, prop, _Class) && _superPropSet(_Class, prop, value, _Class, 1)`
+                ctx.ast.expression_logical(span, get_call, operator, set_call)
+            } else {
+                // The above covers all types of `AssignmentOperator`
+                unreachable!();
+            }
+        }
+    }
+
     /// Member:
     ///  `_superPropGet(_Class, prop, _Class)`
     ///
@@ -155,4 +301,28 @@ impl<'a, 'ctx> ClassProperties<'a, 'ctx> {
         // `_superPropGet(_Class, prop, _Class)` or `_superPropGet(_Class, prop, _Class, 2)`
         self.ctx.helper_call_expr(Helper::SuperPropGet, span, arguments, ctx)
     }
+
+    /// `_superPropSet(_Class, prop, value, _Class, 1)`
+    fn create_super_prop_set(
+        &mut self,
+        span: Span,
+        property: Expression<'a>,
+        value: Expression<'a>,
+        ctx: &mut TraverseCtx<'a>,
+    ) -> Expression<'a> {
+        let temp_binding = self.current_class_mut().bindings.get_or_init_static_binding(ctx);
+        let arguments = ctx.ast.vec_from_array([
+            Argument::from(temp_binding.create_read_expression(ctx)),
+            Argument::from(property),
+            Argument::from(value),
+            Argument::from(temp_binding.create_read_expression(ctx)),
+            Argument::from(ctx.ast.expression_numeric_literal(
+                SPAN,
+                1.0,
+                None,
+                NumberBase::Decimal,
+            )),
+        ]);
+        self.ctx.helper_call_expr(Helper::SuperPropSet, span, arguments, ctx)
+    }
 }

tasks/transform_conformance/snapshots/oxc.snap.md

@@ -1,6 +1,6 @@
 commit: 54a8389f
 
-Passed: 112/127
+Passed: 113/128
 
 # All Passed:
 * babel-plugin-transform-class-static-block
@@ -16,7 +16,7 @@ Passed: 112/127
 * regexp
 
 
-# babel-plugin-transform-class-properties (13/16)
+# babel-plugin-transform-class-properties (14/17)
 * static-super-tagged-template/input.js
 x Output mismatch
 

tasks/transform_conformance/tests/babel-plugin-transform-class-properties/test/fixtures/static-super-assignment-expression/input.js

@@ -0,0 +1,50 @@
+const ident = "A";
+
+class Outer {
+  static B = () => {
+    // Transform
+    super.A = 1;
+    super.A += 1;
+    super.A -= 1;
+    super.A &&= 1;
+    super.A ||= 1;
+
+    super[ident] = 1;
+    super[ident] += 1;
+    super[ident] -= 1;
+    super[ident] &&= 1;
+    super[ident] ||= 1;
+
+    class Inner {
+      method() {
+        // Don't transform
+        super.A = 1;
+        super.A += 1;
+        super.A -= 1;
+        super.A &&= 1;
+        super.A ||= 1;
+
+        super[ident] = 1;
+        super[ident] += 1;
+        super[ident] -= 1;
+        super[ident] &&= 1;
+        super[ident] ||= 1;
+      }
+
+      static staticMethod() {
+        // Don't transform
+        super.A = 1;
+        super.A += 1;
+        super.A -= 1;
+        super.A &&= 1;
+        super.A ||= 1;
+
+        super[ident] = 1;
+        super[ident] += 1;
+        super[ident] -= 1;
+        super[ident] &&= 1;
+        super[ident] ||= 1;
+      }
+    }
+  };
+}

tasks/transform_conformance/tests/babel-plugin-transform-class-properties/test/fixtures/static-super-assignment-expression/output.js

@@ -0,0 +1,53 @@
+var _Outer;
+
+const ident = "A";
+
+class Outer {}
+
+_Outer = Outer;
+babelHelpers.defineProperty(Outer, "B", () => {
+  // Transform
+  babelHelpers.superPropSet(_Outer, "A", 1, _Outer, 1);
+  babelHelpers.superPropSet(_Outer, "A", babelHelpers.superPropGet(_Outer, "A", _Outer) + 1, _Outer, 1);
+  babelHelpers.superPropSet(_Outer, "A", babelHelpers.superPropGet(_Outer, "A", _Outer) - 1, _Outer, 1);
+  babelHelpers.superPropGet(_Outer, "A", _Outer) && babelHelpers.superPropSet(_Outer, "A", 1, _Outer, 1);
+  babelHelpers.superPropGet(_Outer, "A", _Outer) || babelHelpers.superPropSet(_Outer, "A", 1, _Outer, 1);
+
+  babelHelpers.superPropSet(_Outer, ident, 1, _Outer, 1);
+  babelHelpers.superPropSet(_Outer, ident, babelHelpers.superPropGet(_Outer, ident, _Outer) + 1, _Outer, 1);
+  babelHelpers.superPropSet(_Outer, ident, babelHelpers.superPropGet(_Outer, ident, _Outer) - 1, _Outer, 1);
+  babelHelpers.superPropGet(_Outer, ident, _Outer) && babelHelpers.superPropSet(_Outer, ident, 1, _Outer, 1);
+  babelHelpers.superPropGet(_Outer, ident, _Outer) || babelHelpers.superPropSet(_Outer, ident, 1, _Outer, 1);
+
+  class Inner {
+    method() {
+      // Don't transform
+      super.A = 1;
+      super.A += 1;
+      super.A -= 1;
+      super.A &&= 1;
+      super.A ||= 1;
+
+      super[ident] = 1;
+      super[ident] += 1;
+      super[ident] -= 1;
+      super[ident] &&= 1;
+      super[ident] ||= 1;
+    }
+
+    static staticMethod() {
+      // Don't transform
+      super.A = 1;
+      super.A += 1;
+      super.A -= 1;
+      super.A &&= 1;
+      super.A ||= 1;
+
+      super[ident] = 1;
+      super[ident] += 1;
+      super[ident] -= 1;
+      super[ident] &&= 1;
+      super[ident] ||= 1;
+    }
+  }
+});