fix(javascript): honor cancellation before evidence publication (#1098)

src/application/javascript/JavaScriptAnalysisControl.test.ts

@@ -0,0 +1,39 @@
+import { setImmediate } from "node:timers/promises";
+import { describe, expect, it } from "vitest";
+import { completeJavaScriptAnalysisSteps } from "./JavaScriptAnalysisControl.js";
+
+describe("JavaScript cooperative computation lifecycle", () => {
+  it("observes scheduler cancellation and closes abandoned work", async () => {
+    const controller = new AbortController();
+    let released = false;
+    function* work(): Generator<void, number> {
+      try {
+        for (;;) yield;
+      } finally {
+        released = true;
+      }
+    }
+    const cancellation = setImmediate().then(() => controller.abort());
+    await expect(
+      completeJavaScriptAnalysisSteps(work(), controller.signal),
+    ).rejects.toMatchObject({ reason: "cancelled" });
+    await cancellation;
+    expect(released).toBe(true);
+  });
+
+  it("does not start pre-cancelled work and preserves completed values", async () => {
+    const controller = new AbortController();
+    controller.abort();
+    let started = false;
+    function* work(): Generator<void, number> {
+      started = true;
+      yield;
+      return 42;
+    }
+    await expect(
+      completeJavaScriptAnalysisSteps(work(), controller.signal),
+    ).rejects.toMatchObject({ reason: "cancelled" });
+    expect(started).toBe(false);
+    expect(await completeJavaScriptAnalysisSteps(work())).toBe(42);
+  });
+});