From ca579641a45bebcd629b2081b101233613375596 Mon Sep 17 00:00:00 2001
From: Chris Tate <chris@ctate.dev>
Date: Thu, 22 Oct 2026 10:04:30 -0500
Subject: [PATCH] Index quoted get: and set: method names under their own keys

---
 .../lowering/class-dynamic-dispatch.ts        | 13 +++++-----
 .../class-quoted-accessor-keys.mjs.json       |  6 +++++
 tests/corpus/class-quoted-accessor-keys.mjs   | 26 +++++++++++++++++++
 .../class-quoted-accessor-keys.mjs.json       |  1 +
 4 files changed, 40 insertions(+), 6 deletions(-)
 create mode 100644 packages/compiler/test/ts7/baselines/order-parity/tests/corpus/class-quoted-accessor-keys.mjs.json
 create mode 100644 tests/corpus/class-quoted-accessor-keys.mjs
 create mode 100644 tests/harness/corpus-costs/class-quoted-accessor-keys.mjs.json

diff --git a/packages/compiler/src/frontend/lowering/class-dynamic-dispatch.ts b/packages/compiler/src/frontend/lowering/class-dynamic-dispatch.ts
index 79deb2aeb..e792de957 100644
--- a/packages/compiler/src/frontend/lowering/class-dynamic-dispatch.ts
+++ b/packages/compiler/src/frontend/lowering/class-dynamic-dispatch.ts
@@ -477,7 +477,7 @@ interface ReceiverIndex {
   /** By a method or generic method its base chain declares. */
   methods: Map<string, number[]>;
   /** By a method, generic method or accessor its base chain declares (an
-   * accessor under its property name), or a field it has. */
+   * accessor under its key and under its property name), or a field it has. */
   members: Map<string, number[]>;
   rooted: number[];
 }
@@ -504,11 +504,12 @@ function receiverIndex(lowerer: Lowerer, plans: readonly PropertyReceiver[]): Re
     for (let c: ClassInfo | null = info; c; c = c.base) {
       for (const name of c.methods.keys()) {
         add(methods, name, position);
-        add(
-          members,
-          name.startsWith("get:") || name.startsWith("set:") ? name.slice(4) : name,
-          position,
-        );
+        // A `get:`/`set:` key is an accessor of the property after the
+        // prefix, or a method whose quoted name has that prefix; the test
+        // looks up both.
+        add(members, name, position);
+        if (name.startsWith("get:") || name.startsWith("set:"))
+          add(members, name.slice(4), position);
       }
       if (c.genericMethods)
         for (const name of c.genericMethods.keys()) {
diff --git a/packages/compiler/test/ts7/baselines/order-parity/tests/corpus/class-quoted-accessor-keys.mjs.json b/packages/compiler/test/ts7/baselines/order-parity/tests/corpus/class-quoted-accessor-keys.mjs.json
new file mode 100644
index 000000000..234634ebd
--- /dev/null
+++ b/packages/compiler/test/ts7/baselines/order-parity/tests/corpus/class-quoted-accessor-keys.mjs.json
@@ -0,0 +1,6 @@
+{
+ "order": [
+  "<repo>/tests/corpus/class-quoted-accessor-keys.mjs"
+ ],
+ "diags": []
+}
diff --git a/tests/corpus/class-quoted-accessor-keys.mjs b/tests/corpus/class-quoted-accessor-keys.mjs
new file mode 100644
index 000000000..637300b43
--- /dev/null
+++ b/tests/corpus/class-quoted-accessor-keys.mjs
@@ -0,0 +1,26 @@
+// Methods whose quoted names begin with "get:" or "set:", next to an
+// accessor of the property after the prefix, read and called through
+// untyped values.
+class Quoted {
+  "get:size"() {
+    return "method get:size";
+  }
+  "set:size"(value) {
+    return `method set:size ${value}`;
+  }
+  get size() {
+    return 3;
+  }
+}
+class Sized {
+  constructor() {
+    this.size = 5;
+  }
+}
+const values = [new Quoted(), new Sized(), { "get:size": () => "record get:size", size: 1 }];
+for (const value of values) {
+  const getter = value["get:size"];
+  console.log(typeof getter, getter?.call(value));
+  console.log(typeof value["set:size"], value.size);
+  if (value instanceof Quoted) console.log(value["get:size"](), value["set:size"](7));
+}
diff --git a/tests/harness/corpus-costs/class-quoted-accessor-keys.mjs.json b/tests/harness/corpus-costs/class-quoted-accessor-keys.mjs.json
new file mode 100644
index 000000000..81da85b90
--- /dev/null
+++ b/tests/harness/corpus-costs/class-quoted-accessor-keys.mjs.json
@@ -0,0 +1 @@
+{ "plain": 3900, "san": 4000 }