From 77fddcde78f0a2a8be32d5e3aeeabd7215a7fcd4 Mon Sep 17 00:00:00 2001
From: Danijel Martinek <danijel@fraqtal.xyz>
Date: Tue, 12 May 2026 22:40:44 +0200
Subject: [PATCH] feat(core-shared/instrumentation): withCapture attaches
 runtime __captured marker

---
 .../src/instrumentation/with-capture.test.ts          | 11 +++++++++++
 .../core-shared/src/instrumentation/with-capture.ts   |  2 ++
 2 files changed, 13 insertions(+)

diff --git a/packages/core-shared/src/instrumentation/with-capture.test.ts b/packages/core-shared/src/instrumentation/with-capture.test.ts
index 28b4803..179534f 100644
--- a/packages/core-shared/src/instrumentation/with-capture.test.ts
+++ b/packages/core-shared/src/instrumentation/with-capture.test.ts
@@ -3,6 +3,7 @@ import { withCapture } from "@/instrumentation/with-capture";
 import type { ILogger } from "@/instrumentation/logger.interface";
 import { isReported } from "@/instrumentation/reported-flag";
 import type { Captured } from "@/conformance/brands";
+import { isCaptured } from "@/conformance/brand-runtime";
 
 function makeLogger(): ILogger & { captureException: ReturnType<typeof vi.fn> } {
   return {
@@ -70,3 +71,13 @@ describe("withCapture — brand", () => {
     expectTypeOf(wrapped).toMatchTypeOf<Captured<typeof fn>>();
   });
 });
+
+describe("withCapture — runtime brand", () => {
+  it("attaches __captured as a non-enumerable property on the wrapped function", async () => {
+    const logger = makeLogger();
+    const fn = async (a: number) => a + 1;
+    const wrapped = withCapture(logger, { layer: "use-case" }, fn);
+    expect(isCaptured(wrapped)).toBe(true);
+    expect(Object.keys(wrapped)).not.toContain("__captured");
+  });
+});
diff --git a/packages/core-shared/src/instrumentation/with-capture.ts b/packages/core-shared/src/instrumentation/with-capture.ts
index ed17420..9807a81 100644
--- a/packages/core-shared/src/instrumentation/with-capture.ts
+++ b/packages/core-shared/src/instrumentation/with-capture.ts
@@ -1,5 +1,6 @@
 import type { ILogger } from "./logger.interface";
 import type { Captured } from "../conformance/brands";
+import { attachBrand } from "../conformance/brand-runtime";
 import { isReported, markReported } from "./reported-flag";
 
 /**
@@ -38,5 +39,6 @@ export function withCapture<Args extends unknown[], R>(
       throw err;
     }
   };
+  attachBrand(wrapped, "__captured");
   return wrapped as Captured<(...args: Args) => Promise<R>>;
 }