PR review

Author: timfish

packages/cloudflare/src/workflows.ts

@@ -24,8 +24,11 @@ import { init } from './sdk';
 
 const UUID_REGEX = /^[0-9a-f]{8}-?[0-9a-f]{4}-?[0-9a-f]{4}-?[0-9a-f]{4}-?[0-9a-f]{12}$/i;
 
-async function hashStringToUuid(input: string): Promise<string> {
-  const buf = await crypto.subtle.digest('SHA-1', new TextEncoder().encode(input));
+/**
+ * Hashes a string to a UUID using SHA-1.
+ */
+export async function deterministicTraceIdFromInstanceId(instanceId: string): Promise<string> {
+  const buf = await crypto.subtle.digest('SHA-1', new TextEncoder().encode(instanceId));
   return (
     Array.from(new Uint8Array(buf))
       // We only need the first 16 bytes for the 32 characters
@@ -36,7 +39,9 @@ async function hashStringToUuid(input: string): Promise<string> {
 }
 
 async function propagationContextFromInstanceId(instanceId: string): Promise<PropagationContext> {
-  const traceId = UUID_REGEX.test(instanceId) ? instanceId.replace(/-/g, '') : await hashStringToUuid(instanceId);
+  const traceId = UUID_REGEX.test(instanceId)
+    ? instanceId.replace(/-/g, '')
+    : await deterministicTraceIdFromInstanceId(instanceId);
 
   // Derive sampleRand from last 4 characters of the random UUID
   //

packages/cloudflare/test/workflow.test.ts

@@ -1,7 +1,7 @@
 /* eslint-disable @typescript-eslint/unbound-method */
 import type { WorkflowEvent, WorkflowStep, WorkflowStepConfig } from 'cloudflare:workers';
 import { beforeEach, describe, expect, test, vi } from 'vitest';
-import { instrumentWorkflowWithSentry } from '../src/workflows';
+import { deterministicTraceIdFromInstanceId, instrumentWorkflowWithSentry } from '../src/workflows';
 
 const NODE_MAJOR_VERSION = parseInt(process.versions.node.split('.')[0]!);
 
@@ -74,6 +74,13 @@ describe('workflows', () => {
     vi.clearAllMocks();
   });
 
+  test('hashStringToUuid hashes a string to a UUID for Sentry trace ID', async () => {
+    const UUID_WITHOUT_HYPHENS_REGEX = /^[0-9a-f]{32}$/i;
+    expect(await deterministicTraceIdFromInstanceId('s')).toMatch(UUID_WITHOUT_HYPHENS_REGEX);
+    expect(await deterministicTraceIdFromInstanceId('test-string')).toMatch(UUID_WITHOUT_HYPHENS_REGEX);
+    expect(await deterministicTraceIdFromInstanceId(INSTANCE_ID)).toMatch(UUID_WITHOUT_HYPHENS_REGEX);
+  });
+
   test('Calls expected functions', async () => {
     class BasicTestWorkflow {
       constructor(_ctx: ExecutionContext, _env: unknown) {}