fix delete obj?.#field

acornjs · Apr 24, 2021 · 0f9aabb · 0f9aabb
1 parent 2f90bf9
commit 0f9aabb
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Showing 2 changed files with 15 additions and 2 deletions.
diff --git a/acorn/src/expression.js b/acorn/src/expression.js
@@ -237,8 +237,7 @@ pp.parseMaybeUnary = function(refDestructuringErrors, sawUnary) {
     else if (this.strict && node.operator === "delete" &&
              node.argument.type === "Identifier")
       this.raiseRecoverable(node.start, "Deleting local variable in strict mode")
-    else if (node.operator === "delete" && node.argument.type === "MemberExpression" &&
-             node.argument.property.type === "PrivateIdentifier")
+    else if (node.operator === "delete" && isPrivateFieldAccess(node.argument))
       this.raiseRecoverable(node.start, "Private fields can not be deleted")
     else sawUnary = true
     expr = this.finishNode(node, update ? "UpdateExpression" : "UnaryExpression")
@@ -262,6 +261,13 @@ pp.parseMaybeUnary = function(refDestructuringErrors, sawUnary) {
     return expr
 }
 
+function isPrivateFieldAccess(node) {
+  return (
+    node.type === "MemberExpression" && node.property.type === "PrivateIdentifier" ||
+    node.type === "ChainExpression" && isPrivateFieldAccess(node.expression)
+  )
+}
+
 // Parse call, dot, and `[]`-subscript expressions.
 
 pp.parseExprSubscripts = function(refDestructuringErrors) {

diff --git a/test/tests-class-features-2022.js b/test/tests-class-features-2022.js
@@ -3671,6 +3671,13 @@ test("class C { #aaa; f(f) { f()?.#aaa } }", {
 // super
 testFail("class C extends Base { f() { return super.#aaa } }", "Unexpected token (1:42)", {ecmaVersion: 13})
 
+// delete
+test("class C { #aaa; f() { delete this.#aaa.foo } }", {}, {ecmaVersion: 13})
+test("class C { #aaa; f() { delete this.#aaa?.foo } }", {}, {ecmaVersion: 13})
+testFail("class C { #aaa; f() { delete this.#aaa } }", "Private fields can not be deleted (1:22)", {ecmaVersion: 13})
+testFail("class C { #aaa; f() { delete obj?.#aaa } }", "Private fields can not be deleted (1:22)", {ecmaVersion: 13})
+testFail("class C { #aaa; f() { delete obj?.p.#aaa } }", "Private fields can not be deleted (1:22)", {ecmaVersion: 13})
+
 // unexpected token
 testFail("const obj = #aaa", "Unexpected token (1:12)", {ecmaVersion: 13})
 testFail("const obj = { #aaa }", "Unexpected token (1:14)", {ecmaVersion: 13})