fix(javascript): preserve failure provenance and cleanup ownership

src/application/javascript/JavaScriptAnalysisControl.test.ts

@@ -5,6 +5,7 @@ import { completeJavaScriptAnalysisSteps } from "./JavaScriptAnalysisControl.js"
 describe("JavaScript cooperative computation lifecycle", () => {
   it("observes scheduler cancellation and closes abandoned work", async () => {
     const controller = new AbortController();
+    const reason = { request: "caller cancelled computation" };
     let released = false;
     function* work(): Generator<void, number> {
       try {
@@ -13,17 +14,18 @@ describe("JavaScript cooperative computation lifecycle", () => {
         released = true;
       }
     }
-    const cancellation = setImmediate().then(() => controller.abort());
+    const cancellation = setImmediate().then(() => controller.abort(reason));
     await expect(
       completeJavaScriptAnalysisSteps(work(), controller.signal),
-    ).rejects.toMatchObject({ reason: "cancelled" });
+    ).rejects.toMatchObject({ reason: "cancelled", cause: reason });
     await cancellation;
     expect(released).toBe(true);
   });
 
   it("does not start pre-cancelled work and preserves completed values", async () => {
     const controller = new AbortController();
-    controller.abort();
+    const reason = { request: "caller cancelled computation" };
+    controller.abort(reason);
     let started = false;
     function* work(): Generator<void, number> {
       started = true;
@@ -32,7 +34,7 @@ describe("JavaScript cooperative computation lifecycle", () => {
     }
     await expect(
       completeJavaScriptAnalysisSteps(work(), controller.signal),
-    ).rejects.toMatchObject({ reason: "cancelled" });
+    ).rejects.toMatchObject({ reason: "cancelled", cause: reason });
     expect(started).toBe(false);
     expect(await completeJavaScriptAnalysisSteps(work())).toBe(42);
   });