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Node.js Stack Trace (log)

A realistic Node.js/Express stack trace — a TypeError with V8-style 'at function (file:line:col)' frames including an async frame and internal node: frames. A fixture for testing JS stack-trace parsers.

Preview — first 9 lineslog
TypeError: Cannot read properties of undefined (reading 'email')
    at notifyCustomer (/srv/app/services/order.js:142:31)
    at placeOrder (/srv/app/services/order.js:88:5)
    at OrderController.create (/srv/app/controllers/order.js:54:20)
    at Layer.handle [as handle_request] (/srv/app/node_modules/express/lib/router/layer.js:95:5)
    at next (/srv/app/node_modules/express/lib/router/route.js:144:13)
    at processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async Server.<anonymous> (/srv/app/server.js:29:3)

Specifications

Language
Node.js
Exception
TypeError
Frames
7
Has Async
true

What is a .log file?

LOG files are plain-text records of events emitted by software, typically one entry per line with a timestamp, severity, and message. There is no single standard, so formats range from unstructured text to structured JSON lines. They are central to debugging, monitoring, and auditing.

How to use this file

Use an example LOG file to test log parsers, timestamp and severity extraction, line-oriented streaming, and ingestion into monitoring or analysis pipelines.

How to use this file for testing

“Node.js Stack Trace (log)” is a deterministic Novus Examples fixture for Log parsing, Error handling. Access logs and JSON-lines application logs — for testing log parsers, tailers, and ingestion pipelines.

Documented properties for this file: Node.js. Compare results against paired or grouped companions on this page when present (clean↔damaged, searchable↔scanned, or format twins) so scores stay reproducible across runs.

Download the file once, keep the path stable in CI or local scripts, and treat the spec table as the contract: dimensions, seeds, field lists, and roles are intentional. Corrupt or invalid samples are labelled as such — expect parsers to fail loudly rather than silently accept them.

Data fixtures document their exact quirks — delimiters, encodings, null handling, schema, and row counts — in the spec table. Point your parser or importer at the file and assert it handles the documented edge cases; clean and deliberately-messy siblings make before/after diffs straightforward.

Code examples

grep -i error stacktrace-node.log | head
awk '{print $1, $2, $NF}' stacktrace-node.log | head

Generated by generation/data_logs.py. Free for any use, no attribution required — license.