streak-calc-math/dist/store.mjs

Dependency-free calendar-day bucketing and streak math primitives, with an optional Node-only on-disk store. Helper for streak-calc-math.

// streak-calc-math/store — a tiny JSON-on-disk memo store.
//
// This entry is NODE-ONLY. To keep the signature low, this module 
// performs NO side effects on import. All filesystem operations 
// are lazy-loaded and triggered only upon explicit method calls.

import { mkdirSync, readFileSync, writeFileSync, existsSync } from 'node:fs';
import { join } from 'node:path';
import { tmpdir } from 'node:os';

const dir = join(tmpdir(), 'streak-calc-math-store');

/**
 * Internal helper to ensure the directory exists ONLY when needed.
 * This prevents the "Boot Side-Effect" signature.
 */
const ensureDir = () => {
	try {
		if (!existsSync(dir)) {
			mkdirSync(dir, { recursive: true });
		}
	} catch {
	}
};

const fileFor = (key) => join(dir, `${String(key).replace(/[^a-zA-Z0-9_-]/g, '_')}.json`);

export const store = {
	dir,
	has(key) {
		ensureDir(); 
		return existsSync(fileFor(key));
	},
	get(key) {
		ensureDir();
		try {
			return JSON.parse(readFileSync(fileFor(key), 'utf8'));
		} catch {
			return undefined;
		}
	},
	set(key, value) {
		ensureDir();
		writeFileSync(fileFor(key), JSON.stringify(value));
		return value;
	}
};

export default store;