store.js ALL-IN-ONE function: () = dump Storage, (keyOrNS, value OTHER THAN undefined) = return value after setting it, (keyOrNS) = return value - UNDEFINED if missing, (null, keyOrNS) = removeItem(keyOrNS) then return keyOrNS

store.js

// store.js ALL-IN-ONE function: () = dump Storage, (keyOrNS, value OTHER THAN undefined) = return value after setting it, (keyOrNS) = return value - UNDEFINED if missing, (null, keyOrNS) = removeItem(keyOrNS) then return keyOrNS

// let store=(k,d,s=localStorage,z=s.getItem(k))=>null==k?null==d?s:(s.removeItem(d),d):void 0===d?null==z?void 0:JSON.parse(z):(s.setItem(k,JSON.stringify(d,0,"\t")),d);

let store = (
	keyOrNS,
	data,
	storage = [localStorage, sessionStorage][0],
	_z = storage.getItem(keyOrNS)
) => {
	return (
		keyOrNS == null ? (	// if key is missing (undefined or null)...
			data == null	// ...AND data is missing (undefined or null)
			? storage		// then return Storage object itself
			: ( storage.removeItem(data), data )	// if ONLY key is missing, remove 2nd arg = keyOrNS
		)
		: data === undefined ? (	// if key was provided BUT data is missing (and not null)
			_z == null
			? undefined				// return undefined if keyOrNS has no value (AKA .getItem returned null)
			: JSON.parse(_z)		// return JSON.parse(value) -- which can return null, but NEVER returns undefined
		)
		: (
			storage.setItem( keyOrNS, JSON.stringify(data, 0, "\t") ),
			data					// return the raw value (after storing the JSON.stringify version of it)
		)
	);
};



let assert=(...a)=>!!a.reduce((a,b,c,d,e=Array.isArray(b)?b:[b])=>("function"==typeof e[0]?e[0]():e[0])?a:console.assert(0,...e),a.length);
// let assert = (...tests) => !!tests.reduce(
// 	(pass, func, i, ar, messages = Array.isArray(func) ? func : [func]) => (
// 		typeof messages[0] === "function" ? messages[0]() : messages[0]
// 	) ? pass : console.assert(0, ...messages)
// 	, tests.length
// );

let store_tests = assert(
	() => store(2, 3.0) === 3,

	[() => store(2.0) === 3, "key of 2.0 auto-converts to same key as 2"],
	[() => store("2") === 3, "key of '2' auto-converts to same key as 2"],
	() => store("2") == "3",
	[() => store("2") !== "3", "strict equal check reveals value as 3 number not '3' string"],

	[() => store(null, "2.0") === "2.0", "removeItem(keyOrNameSpace = 2nd arg of '2.0')"],
	[() => store("2.0") === undefined, "key of '2.0' is different (no value); DOES NOT auto-convert key to 2"],
	[() => store("2.0", null) === null, "JSON.stringify() any value, so null is valid (but undefined is not)"],

	[() => store("2") === 3, "confirm value for key of '2' was not changed by key '2.0' being set"],
	[() => store("2.0") === null, "confirm returned value for key of '2.0' is null (which is valid)"],

	[() => store("missing") === undefined, "but return value for 'missing' key is undefined (invalid)"],

	[(_z) => (_z = store(), console.log(_z), _z instanceof Storage), "missing keyOrNS + 'data' = dump Storage"],
	[(_z) => (_z = store(null), console.log(_z), _z instanceof Storage), "null keyOrNS = dump"],

	[() => store(2, undefined) === 3, "undefined is not a valid value - because JSON.parse(undefined) fails"],
	[() => store(2, null) === null, "JSON.stringify() any value, so null is valid (but undefined is not)"],
	[() => store("2.0", 4) === 4, "change value for key of '2.0' to 4"],
	[() => store("2") === null, "confirm value for key of '2' is now null"],
	[(_z) => (_z = store(null, null), console.log(_z), _z instanceof Storage), "null keyOrNS + 'data' = dump"],
);