function-location

locateV8() returns the absolute source file path for a function or class at runtime.

Install

npm install function-location

Supports Node.js 16+.

Usage

import { locateV8 } from 'function-location';

class ExampleClass {}
function exampleFunction() {}

locateV8(ExampleClass);     // /path/to/file.ts
locateV8(exampleFunction);  // /path/to/file.ts

API

• locateV8(input: Function): string | undefined
• Throws Function argument expected when input is not a function/class constructor.
• Returns undefined for anonymous/native/builtins where metadata is unavailable.

Performance sample

This library uses a synchronous native addon lookup instead of the inspector protocol.

Sample comparison against an inspector-protocol baseline:

Approach	Median time / call	Relative speed
locate	0.1197 µs	1878.60x faster
inspector protocol	224.8900 µs	baseline

Results vary by environment; treat them as sample measurements only. Methodology and raw samples: docs/BENCHMARK.md

Links

• Contributing / support matrix
• MIT License