Changelog

[2.0.1] - 2026-02-25

Runtime crash: calcSpa(... , []) with an empty angles array no longer crashes. The empty-array guard is now consistent between getSpa and calcSpa.
Silent wrong output: getSpa with options.function: SPA_ZA or SPA_ZA_INC now returns NaN for sunrise, solarNoon, and sunset instead of silently returning 0. calcSpa returns "N/A" for those fields. The zero values were misleading: those fields are never computed by non-RTS function codes.
lib/spa.js internal file header corrected from // dist/spa.js to // lib/spa.js.
wiki-sync.yml: workflow now handles first-run initialization when the GitHub Wiki repository does not yet exist. Replaces actions/checkout@v4 for the wiki step with a git clone || git init pattern.
Removed package-import-method=hardlink from .npmrc: it is pnpm's default since v7 and caused npm warn Unknown project config because npm reads .npmrc too.
CI pack-check grep now uses a word-boundary pattern, preventing false matches on files with similar prefixes.

Validation: options.function is now validated before the SPA calculation. Passing an invalid function code throws a descriptive RangeError instead of silently producing wrong results.
Validation: Passing custom angles with a non-RTS function code (SPA_ZA or SPA_ZA_INC) now throws RangeError. Custom angle calculations require suntransit, which is only computed by SPA_ZA_RTS and SPA_ALL.
TypeScript function overloads for getSpa and calcSpa: the angles parameter is typed as [number, ...number[]] (non-empty tuple), so TypeScript rejects empty arrays at compile time and narrows the return type automatically.
SpaFormattedAnglesResult interface for the formatted angles array, consistent with the existing SpaAnglesResult interface on the raw side.
CI workflows now declare explicit permissions: contents: read on all jobs.
API Reference wiki updated: inline anonymous types replaced with named SpaAnglesResult and SpaFormattedAnglesResult interfaces; new Named Types import block added; angles parameter type and new throws documented.
Architecture wiki updated to document all exported interfaces from src/types.ts.

TypeScript wrapper (src/index.ts, src/types.ts) with full type definitions
Dual CJS and ESM builds via tsup (dist/index.cjs, dist/index.mjs)
TypeScript declaration files (dist/index.d.ts, dist/index.d.mts)
formatTime() utility export for converting fractional hours to HH:MM:SS
Input validation with descriptive TypeError and RangeError messages
Function code exports: SPA_ZA, SPA_ZA_INC, SPA_ZA_RTS, SPA_ALL
Test suite: 61 ESM assertions and 17 CJS assertions
GitHub Actions CI workflow (Node 20/22/24 matrix, typecheck, pack-check)
GitHub Wiki with architecture, API reference, twilight calculations, and algorithm documentation
NREL attribution in LICENSE and README
pnpm-workspace.yaml, .editorconfig, .npmrc, .nvmrc config files

Core algorithm moved from dist/spa.js to lib/spa.js (same code, clearer location)
package.json rewritten: proper exports map, files, engines, sideEffects, all required fields
Author corrected to "Aric Camarata"
repository.url corrected to use git+https:// prefix (no npm publish warnings)
engines.node set to >=20
Description expanded with full keyword coverage
LICENSE year corrected to 2023-2026
README rewritten with badges, full API tables, quick start, and NREL acknowledgments

Major fix for discrepancies between this implementation and the original NREL C reference
Added bin/ folder for compiling and testing against the C reference executable
All 10 global test cases now produce identical output to the C reference