Capture structured Error.cause data (#148)

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Author: petyosi

.changeset/logfire-bugs-metadata.md

@@ -0,0 +1,5 @@
+---
+"logfire": patch
+---
+
+Add npm bugs metadata for the Logfire package.

.changeset/tame-errors-cause.md

@@ -0,0 +1,5 @@
+---
+'logfire': patch
+---
+
+Include `Error.cause` chains in recorded exception stacktraces and as structured `exception.cause` attributes.

examples/express/.env.example

@@ -1,5 +1,5 @@
 # Used for reporting traces to Logfire
 # Change the URL if you're using a different Logfire instance
 # LOGFIRE_BASE_URL=https://logfire-api.pydantic.dev/
-LOGFIRE_WRITE_TOKEN=your-write-token
+LOGFIRE_TOKEN=your-write-token
 EXPRESS_PORT=8080

examples/express/app.ts

@@ -5,6 +5,28 @@ import * as logfire from '@pydantic/logfire-node'
 const PORT: number = parseInt(process.env.EXPRESS_PORT || '8080')
 const app: Express = express()
 
+function createStructuredCauseDemoError(): Error {
+  const databaseCause = Object.assign(new Error('database connection rejected'), {
+    attempt: 3,
+    details: {
+      host: 'primary-db.internal',
+      pool: 'checkout-writes',
+      retryable: true,
+    },
+    statusCode: 503,
+  })
+
+  const serviceCause = Object.assign(new Error('checkout storage call failed', { cause: databaseCause }), {
+    operation: 'checkout.create_order',
+    requestId: 'demo-request-structured-cause',
+  })
+
+  return Object.assign(new Error('structured Error.cause demo failed', { cause: serviceCause }), {
+    cartId: 'cart_demo_123',
+    customerTier: 'enterprise',
+  })
+}
+
 function getRandomNumber(min: number, max: number) {
   return Math.floor(Math.random() * (max - min) + min)
 }
@@ -24,13 +46,21 @@ app.get('/rolldice', (req, res) => {
   res.send(getRandomNumber(1, 6).toString())
 })
 
+app.get('/structured-cause-error', (_req, _res) => {
+  throw createStructuredCauseDemoError()
+})
+
 // Report an error to Logfire, using the Express error handler.
 app.use((err: Error, _req: Request, res: Response, _next: () => unknown) => {
-  logfire.reportError(err.message, err)
+  logfire.reportError(err.message, err, {
+    demo: 'structured-error-cause',
+    expectedAttributes: ['exception.cause', 'logfire.json_schema'],
+  })
   res.status(500)
-  res.send('An error occured')
+  res.send('An error occurred')
 })
 
 app.listen(PORT, () => {
   console.log(`Listening for requests on http://localhost:${PORT}/rolldice`)
+  console.log(`Structured cause demo: http://localhost:${PORT}/structured-cause-error`)
 })

examples/node/.env

@@ -13,6 +13,9 @@
   },
   "sideEffects": false,
   "homepage": "https://pydantic.dev/logfire",
+  "bugs": {
+    "url": "https://github.com/pydantic/logfire-js/issues"
+  },
   "license": "MIT",
   "publishConfig": {
     "access": "public"