From 9febfe8ca3939e79923a8e3a35d47cbcb89e46ce Mon Sep 17 00:00:00 2001
From: Chris Tate <chris@ctate.dev>
Date: Tue, 20 Oct 2026 02:07:18 -0500
Subject: [PATCH] Place a quoted name field among an error's fields

The position of an Error subclass's own `name` among its fields was found
from identifier keys only, so a quoted `"name"` field, other quoted
fields, and `this["name"] = ...` in a constructor were not seen, and
`name` was listed last. Field keys and constructor assignments now read
any statically spelled key: an identifier, a quoted string, a number in
its canonical spelling, or a computed string literal.
---
 .../src/frontend/lowering/error-name-order.ts | 32 +++++++++++++------
 tests/corpus/6403-error-own-name-order.ts     |  6 ++++
 tests/corpus/6404-error-own-name-order-js.js  | 10 ++++++
 3 files changed, 38 insertions(+), 10 deletions(-)

diff --git a/packages/compiler/src/frontend/lowering/error-name-order.ts b/packages/compiler/src/frontend/lowering/error-name-order.ts
index 8523b47cb..7453d123e 100644
--- a/packages/compiler/src/frontend/lowering/error-name-order.ts
+++ b/packages/compiler/src/frontend/lowering/error-name-order.ts
@@ -6,17 +6,27 @@ type ErrorClassLink = Pick<ClassInfo, "decl" | "ctor" | "paramProps"> & {
   base: ErrorClassLink | null;
 };
 
-/** Whether `node` is an assignment to `this.<name>`, and the name. */
+/** The property key a member or element-access name spells statically:
+ * an identifier, a quoted string, a number in its canonical spelling, or a
+ * computed string literal. Null for other keys. */
+function staticKeyText(name: ts.Node): string | null {
+  if (ts.isIdentifier(name) || ts.isStringLiteral(name)) return name.text;
+  if (ts.isNumericLiteral(name)) return String(Number(name.text));
+  if (ts.isComputedPropertyName(name)) return staticKeyText(name.expression);
+  return null;
+}
+
+/** Whether `node` is an assignment to `this.<name>` or `this["<name>"]`,
+ * and the name. */
 function thisAssignmentName(node: ts.Node): string | null {
   if (!ts.isBinaryExpression(node) || node.operatorToken.kind !== ts.SyntaxKind.EqualsToken)
     return null;
   const target = node.left;
-  if (
-    !ts.isPropertyAccessExpression(target) ||
-    target.expression.kind !== ts.SyntaxKind.ThisKeyword
-  )
-    return null;
-  return ts.isIdentifier(target.name) ? target.name.text : null;
+  if (ts.isPropertyAccessExpression(target) && target.expression.kind === ts.SyntaxKind.ThisKeyword)
+    return ts.isIdentifier(target.name) ? target.name.text : null;
+  if (ts.isElementAccessExpression(target) && target.expression.kind === ts.SyntaxKind.ThisKeyword)
+    return staticKeyText(target.argumentExpression);
+  return null;
 }
 
 /** Where an Error subclass instance's own `name` sits among its fields when
@@ -45,15 +55,17 @@ export function errorNameAfterField(
   for (const link of chain) {
     for (const property of link.paramProps ?? []) create(property.name);
     for (const member of link.decl!.members.nodes) {
-      if (!ts.isPropertyDeclaration(member) || !ts.isIdentifier(member.name)) continue;
+      if (!ts.isPropertyDeclaration(member)) continue;
+      const key = staticKeyText(member.name);
+      if (key === null) continue;
       if (
         member.modifiers?.nodes.some(
           (m) => m.kind === ts.SyntaxKind.StaticKeyword || m.kind === ts.SyntaxKind.DeclareKeyword,
         )
       )
         continue;
-      if (member.name.text === "name") return last;
-      create(member.name.text);
+      if (key === "name") return last;
+      create(key);
     }
     const body = link.ctor?.body;
     if (!body) continue;
diff --git a/tests/corpus/6403-error-own-name-order.ts b/tests/corpus/6403-error-own-name-order.ts
index 25e59bb7c..d1a5200c4 100644
--- a/tests/corpus/6403-error-own-name-order.ts
+++ b/tests/corpus/6403-error-own-name-order.ts
@@ -57,6 +57,11 @@ class NamedChild extends FieldBase {
   }
 }
 
+class QuotedName extends Error {
+  override "name" = "QuotedName";
+  "quoted-extra" = 1;
+}
+
 class Unnamed extends Error {
   extra = 1;
 }
@@ -83,6 +88,7 @@ show("later field", new LaterNameField("c"));
 show("code then name", new CodeThenName("d"));
 show("child of named", new ChildOfNamed("e"));
 show("named child", new NamedChild("f"));
+show("quoted name field", new QuotedName("q"));
 
 const late = new Unnamed("g");
 late.name = "Late";
diff --git a/tests/corpus/6404-error-own-name-order-js.js b/tests/corpus/6404-error-own-name-order-js.js
index 0b5ad4e82..b5f9b4d32 100644
--- a/tests/corpus/6404-error-own-name-order-js.js
+++ b/tests/corpus/6404-error-own-name-order-js.js
@@ -49,6 +49,15 @@ class Derived extends Base {
   }
 }
 
+class ElementName extends Error {
+  constructor(message) {
+    super(message);
+    this.first = 1;
+    this["name"] = "ElementName";
+    this.second = 2;
+  }
+}
+
 class Unnamed extends Error {
   constructor(message) {
     super(message);
@@ -73,6 +82,7 @@ show("first", new AssignedFirst("b"));
 show("declared field", new DeclaredField("c"));
 show("name field", new NameField("d"));
 show("derived", new Derived("e"));
+show("element name", new ElementName("g"));
 
 const late = new Unnamed("f");
 late.name = "Late";