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

src/application/javascript/JavaScriptAnalysisControl.ts

@@ -0,0 +1,44 @@
+import { setImmediate } from "node:timers/promises";
+import { ArtifactReaderFailure } from "../../artifacts/ArtifactReader.js";
+
+/** Reject cancelled application work before computing or publishing more results. */
+export const assertJavaScriptAnalysisActive = (signal?: AbortSignal): void => {
+  if (signal?.aborted === true)
+    throw new ArtifactReaderFailure(
+      "cancelled",
+      "JavaScript application analysis cancelled",
+    );
+};
+
+/** Let request control messages run, then recheck the current analysis intent. */
+export const checkpointJavaScriptAnalysis = async (
+  signal?: AbortSignal,
+): Promise<void> => {
+  assertJavaScriptAnalysisActive(signal);
+  await setImmediate();
+  assertJavaScriptAnalysisActive(signal);
+};
+
+/** Drive bounded owned-domain steps while permitting cancellation and control I/O. */
+export const completeJavaScriptAnalysisSteps = async <Value>(
+  steps: Iterator<void, Value, void>,
+  signal?: AbortSignal,
+): Promise<Value> => {
+  let deadline = performance.now() + 8;
+  try {
+    for (;;) {
+      assertJavaScriptAnalysisActive(signal);
+      const step = steps.next();
+      if (step.done) {
+        assertJavaScriptAnalysisActive(signal);
+        return step.value;
+      }
+      if (performance.now() >= deadline) {
+        await checkpointJavaScriptAnalysis(signal);
+        deadline = performance.now() + 8;
+      }
+    }
+  } finally {
+    steps.return?.();
+  }
+};