fix(vom): fix CI

packages/dsh-plugin-browserskill/src/observation.ts

@@ -12,7 +12,7 @@
  * events, and never move the registry's current pointer.
  */
 
-import { createHash } from "node:crypto";
+import { createHash, randomUUID } from "node:crypto";
 import { readFile, unlink } from "node:fs/promises";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
@@ -78,6 +78,7 @@ const FAILURE_BACKOFF_THRESHOLD = 3;
 const FRAME_RING_SIZE = 2;
 
 export class ObservationService {
+  private readonly scratchNamespace = randomUUID();
   private readonly observations = new Map<string, SessionObservation>();
   private readonly listeners = new Set<(event: ObservationEvent) => void>();
   private readonly captureTimers = new Map<string, unknown>();
@@ -304,9 +305,9 @@ export class ObservationService {
     if (current === undefined || current.dead === true) return;
     if (this.captureInFlight.has(sessionId)) return;
     this.captureInFlight.add(sessionId);
-    // One fixed scratch path per session (overwritten each frame) and always
-    // unlinked after the bytes are read — /tmp must not grow without bound.
-    const outPath = join(tmpdir(), `bsk-obs-${sessionId}.png`);
+    // Stable within this service, isolated from captures owned by other instances.
+    const sessionKey = createHash("sha256").update(sessionId).digest("hex").slice(0, 16);
+    const outPath = join(tmpdir(), `bsk-obs-${this.scratchNamespace}-${sessionKey}.png`);
     let writtenPath = outPath;
     try {
       const result = await this.deps.queue.run(sessionId, () =>

packages/dsh-plugin-browserskill/tests/observation.test.ts

@@ -5,7 +5,7 @@
 import { existsSync, mkdtempSync, writeFileSync } from "node:fs";
 import type { IncomingMessage, ServerResponse } from "node:http";
 import { tmpdir } from "node:os";
-import { join } from "node:path";
+import { basename, dirname } from "node:path";
 import { describe, expect, it } from "vitest";
 import {
   actionForLabel,
@@ -548,8 +548,12 @@ describe("scratch files and thumbnail references", () => {
     );
     const firstOut = runner.calls.filter((c) => c.args[0] === "screenshot").at(-1)?.args;
     const pathOf = (args: string[]) => args[args.indexOf("--out") + 1];
-    expect(pathOf(firstOut ?? [])).toBe(join(tmpdir(), "bsk-obs-s1.png"));
-    expect(existsSync(pathOf(firstOut ?? []))).toBe(false);
+    const firstPath = pathOf(firstOut ?? []);
+    expect(dirname(firstPath)).toBe(tmpdir());
+    expect(basename(firstPath)).toMatch(
+      /^bsk-obs-[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}-[0-9a-f]{16}\.png$/,
+    );
+    expect(existsSync(firstPath)).toBe(false);
     // second frame: same path, deleted again
     service.endAction("s1");
     scheduler.runNext();
@@ -559,11 +563,33 @@ describe("scratch files and thumbnail references", () => {
         scheduler.pending().length === 1,
     );
     const secondOut = runner.calls.filter((c) => c.args[0] === "screenshot").at(-1)?.args;
-    expect(pathOf(secondOut ?? [])).toBe(join(tmpdir(), "bsk-obs-s1.png"));
-    await waitFor(() => !existsSync(pathOf(secondOut ?? [])));
+    const secondPath = pathOf(secondOut ?? []);
+    expect(secondPath).toBe(firstPath);
+    await waitFor(() => !existsSync(secondPath));
     service.dispose();
   });
 
+  it("isolates scratch paths between service instances", async () => {
+    const first = setup({ scheduler: fakeScheduler(), runner: fakeRunner() });
+    const second = setup({ scheduler: fakeScheduler(), runner: fakeRunner() });
+    first.service.addSession("s1");
+    second.service.addSession("s1");
+    first.scheduler.runNext();
+    second.scheduler.runNext();
+    await waitFor(
+      () =>
+        first.service.getState()[0]?.thumbnailAttachmentId !== undefined &&
+        second.service.getState()[0]?.thumbnailAttachmentId !== undefined,
+    );
+    const pathOf = (runner: FakeRunner) => {
+      const args = runner.calls.find((call) => call.args[0] === "screenshot")?.args ?? [];
+      return args[args.indexOf("--out") + 1];
+    };
+    expect(pathOf(first.runner)).not.toBe(pathOf(second.runner));
+    first.service.dispose();
+    second.service.dispose();
+  });
+
   it("keeps the last two distinct frames and evicts the third", async () => {
     let n = 0;
     const runner = fakeRunner({