revert: restore withdrawn receiver growth branch

Restore the contributor tree after the prepared maintenance follow-up was inadvertently pushed following PR closure. Keep all original and maintenance commits in history; no force push or main change.

src/domain/javascript/javascriptSemanticAnalysis.member_mutations.test.ts

@@ -628,22 +628,35 @@ describe("results of methods on an escaped receiver", () => {
     });
   });
 
-  it("keeps a shared result uncertain across a wide escaped receiver (#1495)", () => {
-    const count = 2000;
-    const methods = Array.from(
-      { length: count },
-      (_, index) => `m${index}() { return shared; },`,
-    ).join(" ");
-    const calls = Array.from(
-      { length: count },
-      (_, index) => `box.m${index}().p${index} = ${index};`,
-    ).join(" ");
-    const value = resultValue(
-      `const shared = { token: "TOKEN" }; const box = { ${methods} }; ${calls} return [shared.token];`,
-    );
-    expect(value).toMatchObject({
+  it("expands a receiver's methods once rather than once per call (#1495)", () => {
+    const receiverCalls = (count: number) => {
+      const methods = Array.from(
+        { length: count },
+        (_, index) => `m${index}() { return shared; },`,
+      ).join(" ");
+      const calls = Array.from(
+        { length: count },
+        (_, index) => `box.m${index}().p${index} = ${index};`,
+      ).join(" ");
+      return `const shared = { token: "TOKEN" }; const box = { ${methods} }; ${calls} return [shared.token];`;
+    };
+    const fastest = (body: string) =>
+      Math.min(
+        ...[0, 1].map(() => {
+          const start = performance.now();
+          resultValue(body);
+          return performance.now() - start;
+        }),
+      );
+    resultValue(receiverCalls(100));
+    // Compare growth rather than wall time, which depends on the runner and on
+    // coverage instrumentation. Four times the calls costs about 5-6x here;
+    // re-expanding every method per call cost about 13-14x.
+    const ratio = fastest(receiverCalls(1600)) / fastest(receiverCalls(400));
+    expect(ratio).toBeLessThan(10);
+    expect(resultValue(receiverCalls(400))).toMatchObject({
       status: "array",
       items: [{ value: { status: "unknown" } }],
     });
-  }, 30000);
+  }, 60000);
 });

tests/acceptance/applications/javascriptReturnedReferences.test.ts

@@ -47,10 +47,6 @@ const writes = {
   constructor:
     "function Box() { return shared; } const t = new Box(); t.x = 2;",
   callback: "const get = () => shared; [0].forEach(() => { get().x = 2; });",
-  wideMethods: `const box = { ${Array.from(
-    { length: 64 },
-    (_, index) => `m${index}() { return shared; }`,
-  ).join(", ")} }; box.m0().x = 2; box.m63().other = 3;`,
 };
 const source = [
   ...Object.entries(writes).map(
@@ -65,8 +61,6 @@ const source = [
   "export function unused(){ const shared = {x: 1}; const get = () => shared; get(); return shared.x; }",
   "export function nestedCallable(){ const shared = {x: 1}; const get = () => { const inner = () => shared; return {x: 0}; }; get().x = 2; return shared.x; }",
   "export function unrelated(){ const shared = {x: 1}; const other = {x: 9}; const get = () => shared; get().x = 2; return other.x; }",
-  "export function receiverDistinctScopes(){ const shared = {x: 1}; const box = {outer(){ return shared; }, inner(){ const shared = {x: 9}; return shared; }, noop(){}}; box.noop(); return {outer: shared.x, inner: box.inner().x}; }",
-  "export function receiverDistinctPaths(){ const parent = {left: {x: 1}, right: {x: 9}, keep: 7}; const box = {left(){ return parent.left; }, right(){ return parent.right; }, noop(){}}; box.noop(); return {left: parent.left.x, right: parent.right.x, keep: parent.keep}; }",
 ].join("\n");
 
 const assertReturns = (fields: JavaScriptReturnFields): void => {
@@ -97,17 +91,6 @@ const assertReturns = (fields: JavaScriptReturnFields): void => {
   expect(fields("unrelated")).toContainEqual(
     expect.objectContaining({ path: "", state: "literal", value: 9 }),
   );
-  for (const path of ["/outer", "/inner"])
-    expect(fields("receiverDistinctScopes")).toContainEqual(
-      expect.objectContaining({ path, state: "unknown" }),
-    );
-  for (const path of ["/left", "/right"])
-    expect(fields("receiverDistinctPaths")).toContainEqual(
-      expect.objectContaining({ path, state: "unknown" }),
-    );
-  expect(fields("receiverDistinctPaths")).toContainEqual(
-    expect.objectContaining({ path: "/keep", state: "literal", value: 7 }),
-  );
 };
 
 cliTest(