Tests schreiben für calculate.ts

[PiecePaperCode]

https://github.com/twenty-eight-days/TwentyEightDaysNative/commit/5b9a5357ece601c3af04c8208ab5f563b45de43f

[PiecePaperCode]

---------------------	---------	----------	---------	---------	------------------- File	% Stmts	% Branch	% Funcs	% Lines	Uncovered Line #s
All files	81.66	71.42	60.86	83.92
src	100	100	100	100
App.ts	100	100	100	100
src/controller	100	100	100	100
calculate.ts	100	100	100	100
src/model	78.57	90.9	41.66	80.48
exampleSlice.ts	50	100	0	50	10-13
index.ts	75	100	33.33	85.71	23
storage.ts	83.33	90.9	57.14	83.33	28,36-39,65
src/view/components	73.68	50	63.63	77.77
buttons.tsx	100	100	100	100
datePicker.tsx	57.14	50	33.33	57.14	14-23
periodTable.tsx	66.66	100	60	80	22
src/view/containers	74.19	33.33	61.11	77.77
DataScreen.tsx	100	100	100	100
Footer.tsx	75	100	66.66	75	20
Header.tsx	100	100	100	100
MainScreen.tsx	46.15	33.33	33.33	50	31-43
Screen.tsx	100	100	100	100
src/view/ressources	100	100	100	100
table.png	100	100	100	100
today.png	100	100	100	100
white_today.png	100	100	100	100
---------------------	---------	----------	---------	---------	-------------------

Test Suites: 1 passed, 1 total Tests: 15 passed, 15 total Snapshots: 0 total Time: 2.135 s Ran all test suites.