vega-projection

vega-projection is a thin wrapper around d3-geo that provides cartographic projections primarily for the Vega visualization ecosystem. In production, it works fine for basic projection needs but feels more like a bridge layer than a standalone production library. The API is straightforward - you get projection constructors and transformation functions - but there's virtually no error handling, logging hooks, or resilience features.

The library is purely computational with no I/O or async operations, so connection pooling and timeouts aren't concerns. Memory usage is reasonable for typical map data volumes, though there's no built-in protection against pathological inputs. Error messages are terse when projections fail with invalid coordinates, making debugging coordinate system mismatches painful in production logs.

Configuration is minimal - you set projection parameters and call transform functions. Breaking changes have been rare, which is good, but the library also hasn't evolved much in terms of production-grade features. If you're already in the Vega ecosystem this works fine, but standalone usage feels limited compared to using d3-geo directly where you get better documentation and community support.

vega-projection is fundamentally a wrapper around d3-geo with some additional projection types. It handles the mathematical transformations reliably, but from an ops perspective, it's bare-bones. There's no resource pooling, no caching strategies, and projection calculations happen synchronously with no built-in batching or worker thread support.

The library is stateless which is good for predictability, but you're on your own for performance optimization. When projecting thousands of coordinates in a request handler, you'll feel the CPU impact immediately. There are no observability hooks, no error context beyond basic JavaScript errors, and no configuration for timeout behavior. Memory usage is reasonable for typical workloads, but scales linearly with coordinate volume.

Documentation is sparse—you really need to understand d3-geo's API since this is mostly a thin layer. Breaking changes between minor versions have occurred (projection parameter handling changed between 1.x and 2.x). If you're doing server-side map rendering at scale, you'll need to build your own worker pools and caching layers around this.

vega-projection is a low-level cartographic projection library that does what it says on the tin, but offers little in the way of developer experience niceties. The API is straightforward - you call projection functions and get coordinate transformations - but there's virtually no TypeScript support beyond basic type declarations, and the documentation is sparse at best. You'll find yourself frequently cross-referencing d3-geo documentation since this is largely a wrapper around those projections.

Error handling is minimal and cryptic. Pass invalid coordinates or misconfigure a projection and you'll get silent failures or uninformative errors that require debugging the underlying d3-geo layer. IDE autocompletion works for function names but provides little context about parameters or expected inputs.

For projects already deep in the Vega ecosystem, this makes sense as a dependency. For standalone use, you're better off using d3-geo directly where the community support and documentation are substantially better. The package feels more like an internal Vega utility that was published separately rather than a polished standalone library.