test(core-shared): assert PII scrub runs before Sentry processors

The previous init-server-node tests only checked that an SDK handle
came back — the ADR-017 §7 invariant (PiiScrubSpanProcessor /
PiiScrubLogRecordProcessor registered BEFORE any exporter-facing
processor) was untested. Capture the NodeSDK constructor config via a
local vi.mock override and assert processor ordering for both the
empty-DSN and DSN-set paths.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

packages/core-shared/src/instrumentation/otel/init-server-node.test.ts

@@ -1,5 +1,70 @@
-import { describe, it, expect } from "vitest";
+import { describe, it, expect, vi } from "vitest";
 import { initOtelServerNode } from "./init-server-node";
+import {
+  PiiScrubSpanProcessor,
+  PiiScrubLogRecordProcessor,
+} from "./pii-scrub-processor";
+import { SentryLogRecordForwarder } from "./sentry-bridge";
+
+const captured = vi.hoisted(() => ({ configs: [] as unknown[] }));
+
+// Hoisted alongside `captured`: the vi.mock factory below is hoisted above
+// every top-level statement, so a plain top-level class would still be in its
+// temporal dead zone when the factory runs (ReferenceError).
+const FakeBatchSpanProcessor = vi.hoisted(
+  () =>
+    class FakeBatchSpanProcessor {
+      constructor(public readonly wrapped: unknown) {}
+      onStart() {}
+      onEnd() {}
+      forceFlush() {
+        return Promise.resolve();
+      }
+      shutdown() {
+        return Promise.resolve();
+      }
+    },
+);
+
+// Local mock overrides the setup-file stub (the pattern no-instrumentation.ts
+// documents) so the NodeSDK constructor CONFIG is capturable — the previous
+// tests asserted nothing about it, leaving the ADR-017 §7 security invariant
+// (PII scrub runs before any exporter) untested.
+vi.mock("@opentelemetry/sdk-node", () => ({
+  NodeSDK: class {
+    constructor(cfg: unknown) {
+      captured.configs.push(cfg);
+    }
+    start() {}
+    shutdown() {
+      return Promise.resolve();
+    }
+  },
+  tracing: { BatchSpanProcessor: FakeBatchSpanProcessor },
+}));
+// Instrumentations auto-enable (patch http/undici/pg globals) in their
+// constructors — stub them out entirely, not just registerInstrumentations.
+vi.mock("@opentelemetry/instrumentation", () => ({
+  registerInstrumentations: vi.fn(),
+}));
+vi.mock("@opentelemetry/instrumentation-http", () => ({
+  HttpInstrumentation: class {},
+}));
+vi.mock("@opentelemetry/instrumentation-undici", () => ({
+  UndiciInstrumentation: class {},
+}));
+vi.mock("@opentelemetry/instrumentation-pg", () => ({
+  PgInstrumentation: class {},
+}));
+
+type SdkConfig = {
+  spanProcessors: unknown[];
+  logRecordProcessors: unknown[];
+};
+
+function lastConfig(): SdkConfig {
+  return captured.configs[captured.configs.length - 1] as SdkConfig;
+}
 
 describe("initOtelServerNode", () => {
   it("returns an SDK handle with shutdown()", () => {
@@ -8,16 +73,38 @@ describe("initOtelServerNode", () => {
       serviceName: "test-service",
       environment: "test",
     });
-    expect(sdk).toBeDefined();
     expect(typeof sdk.shutdown).toBe("function");
   });
 
-  it("accepts a DSN and wires the Sentry bridge", () => {
-    const sdk = initOtelServerNode({
+  it("registers only PII scrub processors when DSN is empty", () => {
+    initOtelServerNode({
+      dsn: "",
+      serviceName: "test-service",
+      environment: "test",
+    });
+    const cfg = lastConfig();
+    expect(cfg.spanProcessors).toHaveLength(1);
+    expect(cfg.spanProcessors[0]).toBeInstanceOf(PiiScrubSpanProcessor);
+    expect(cfg.logRecordProcessors).toHaveLength(1);
+    expect(cfg.logRecordProcessors[0]).toBeInstanceOf(
+      PiiScrubLogRecordProcessor,
+    );
+  });
+
+  it("registers PII scrub processors BEFORE the Sentry processors when DSN is set (ADR-017 §7)", () => {
+    initOtelServerNode({
       dsn: "https://test@sentry.io/1",
       serviceName: "test-service",
       environment: "test",
     });
-    expect(sdk).toBeDefined();
+    const cfg = lastConfig();
+    expect(cfg.spanProcessors).toHaveLength(2);
+    expect(cfg.spanProcessors[0]).toBeInstanceOf(PiiScrubSpanProcessor);
+    expect(cfg.spanProcessors[1]).toBeInstanceOf(FakeBatchSpanProcessor);
+    expect(cfg.logRecordProcessors).toHaveLength(2);
+    expect(cfg.logRecordProcessors[0]).toBeInstanceOf(
+      PiiScrubLogRecordProcessor,
+    );
+    expect(cfg.logRecordProcessors[1]).toBeInstanceOf(SentryLogRecordForwarder);
   });
 });