From 46d30c86718d81ad0527f693cb0359d96616c027 Mon Sep 17 00:00:00 2001
From: Chris Tate <chris@ctate.dev>
Date: Sat, 26 Sep 2026 08:00:23 -0500
Subject: [PATCH] Preserve class own-key lowering and verify npm static calls
 (#459)

---
 .../src/frontend/lowering/lower-calls.ts      |  2 +-
 .../fixtures/npm-static/colors-hasown-cli.ts  |  3 +++
 tests/harness/npm-static.test.ts              | 22 ++++++++++++++++---
 3 files changed, 23 insertions(+), 4 deletions(-)
 create mode 100644 tests/fixtures/npm-static/colors-hasown-cli.ts

diff --git a/packages/compiler/src/frontend/lowering/lower-calls.ts b/packages/compiler/src/frontend/lowering/lower-calls.ts
index ddd93499..3fe2a0dd 100644
--- a/packages/compiler/src/frontend/lowering/lower-calls.ts
+++ b/packages/compiler/src/frontend/lowering/lower-calls.ts
@@ -4621,7 +4621,6 @@ export function lowerCall(lowerer: Lowerer, expr: ts.CallExpression): IrExpr {
         lowerer.lowerTestMethodCall(expr, expr.expression) ??
         lowerer.lowerTimeoutMethodCall(expr, expr.expression) ??
         lowerObjectOwnPrototypeCall(lowerer, expr, expr.expression) ??
-        lowerObjectOwnMethodCall(lowerer, expr, expr.expression) ??
         lowerObjectPrototypeCall(lowerer, expr, expr.expression) ??
         lowerStringPrototypeCall(lowerer, expr, expr.expression) ??
         lowerStringMethodCallWithOptionalArgs(lowerer, expr, expr.expression) ??
@@ -4653,6 +4652,7 @@ export function lowerCall(lowerer: Lowerer, expr: ts.CallExpression): IrExpr {
         // hasOwnProperty on a program class CONSTRUCTOR — own statics are
         // compile-time-known, so a literal key folds to a constant.
         lowerClassHasOwnPropertyCall(lowerer, expr, expr.expression) ??
+        lowerObjectOwnMethodCall(lowerer, expr, expr.expression) ??
         // Response constructor-object operations are unsupported in both
         // tiers. Keep their SC2020 inventory contract ahead of the island
         // and generic-call fallbacks (Response.json otherwise reports the
diff --git a/tests/fixtures/npm-static/colors-hasown-cli.ts b/tests/fixtures/npm-static/colors-hasown-cli.ts
new file mode 100644
index 00000000..dc6e73fd
--- /dev/null
+++ b/tests/fixtures/npm-static/colors-hasown-cli.ts
@@ -0,0 +1,3 @@
+import pc from "picocolors";
+
+console.log(pc.hasOwnProperty("bold"), pc.hasOwnProperty("missing"));
diff --git a/tests/harness/npm-static.test.ts b/tests/harness/npm-static.test.ts
index 4c9c07c3..e123c7d2 100644
--- a/tests/harness/npm-static.test.ts
+++ b/tests/harness/npm-static.test.ts
@@ -169,19 +169,35 @@ describe(`npm-static pilots${sanitize ? " (sanitized)" : ""}`, () => {
     expect(nativeRes.exitCode).toBe(nodeRes.exitCode);
   }, 180_000);
 
-  test("picocolors inherited Object methods retain the prototype-method fence", () => {
+  test("picocolors inherited valueOf retains the prototype-method fence", () => {
     const entry = join(pilotRoot, "colors-prototype-cli.ts");
     const { coverage } = analyze(entry, { npmStatic: ["picocolors"] });
     expect(coverage.npmStatic).toEqual([{ package: "picocolors", status: "static" }]);
     expect(coverage.preflightFailed).toBe(false);
     expect(coverage.runtimeFences ?? []).toHaveLength(0);
-    expect(coverage.diagnostics.map((diagnostic) => diagnostic.code)).toEqual(["SC2020", "SC2020"]);
+    expect(coverage.diagnostics.map((diagnostic) => diagnostic.code)).toEqual(["SC2020"]);
     expect(coverage.diagnostics.map((diagnostic) => diagnostic.message)).toEqual([
-      expect.stringContaining(".hasOwnProperty' is part of the standard library types"),
       expect.stringContaining(".valueOf' is part of the standard library types"),
     ]);
   }, 120_000);
 
+  test("picocolors inherited hasOwnProperty matches Node", async () => {
+    const entry = join(pilotRoot, "colors-hasown-cli.ts");
+    const { coverage } = analyze(entry, { npmStatic: ["picocolors"] });
+    expect(coverage.preflightFailed).toBe(false);
+    expect(coverage.diagnostics).toHaveLength(0);
+    expect(coverage.runtimeFences ?? []).toHaveLength(0);
+
+    const binary = await buildStatic(entry, ["picocolors"]);
+    const [nodeRes, nativeRes] = await Promise.all([
+      runBinary("node", [entry]),
+      runBinary(binary, []),
+    ]);
+    expect(nativeRes.stdout).toEqual(nodeRes.stdout);
+    expect(comparableStderr(nativeRes.stderr)).toEqual(nodeRes.stderr);
+    expect(nativeRes.exitCode).toBe(nodeRes.exitCode);
+  }, 180_000);
+
   // Tier 1, auto mode: the eligibility heuristics pick escape-string-regexp
   // (own .d.ts, unminified, no transform markers) without naming it.
   test("--npm-static=auto opts the eligible pilot in", () => {