diff options
Diffstat (limited to 'date-fns/src/differenceInMonths/test.ts')
-rw-r--r-- | date-fns/src/differenceInMonths/test.ts | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/date-fns/src/differenceInMonths/test.ts b/date-fns/src/differenceInMonths/test.ts new file mode 100644 index 0000000..edebb59 --- /dev/null +++ b/date-fns/src/differenceInMonths/test.ts @@ -0,0 +1,188 @@ +/* eslint-env mocha */ + +import assert from 'power-assert' +import differenceInMonths from '.' + +describe('differenceInMonths', function () { + it('returns the number of full months between the given dates', function () { + const result = differenceInMonths( + new Date(2012, 6 /* Jul */, 2, 18, 0), + new Date(2011, 6 /* Jul */, 2, 6, 0) + ) + assert(result === 12) + }) + + it('returns a negative number if the time value of the first date is smaller', function () { + const result = differenceInMonths( + new Date(2011, 6 /* Jul */, 2, 6, 0), + new Date(2012, 6 /* Jul */, 2, 18, 0) + ) + assert(result === -12) + }) + + it('accepts timestamps', function () { + const result = differenceInMonths( + new Date(2014, 7 /* Aug */, 2).getTime(), + new Date(2010, 6 /* Jul */, 2).getTime() + ) + assert(result === 49) + }) + + describe('edge cases', function () { + it('it returns diff of 1 month between Feb 28 2021 and Jan 30 2021', function () { + const result = differenceInMonths( + new Date(2021, 1 /* Feb */, 28), + new Date(2021, 0 /* Jan */, 30) + ) + assert(result === 1) + }) + + it('it returns diff of 1 month between Feb 28 2021 and Jan 31 2021', function () { + const result = differenceInMonths( + new Date(2021, 1 /* Feb */, 28), + new Date(2021, 0 /* Jan */, 31) + ) + assert(result === 1) + }) + + it('it returns diff of 1 month between Nov, 30 2021 and Oct, 31 2021', function () { + const result = differenceInMonths( + new Date(2021, 10 /* Nov */, 30), + new Date(2021, 9 /* Oct */, 31) + ) + assert(result === 1) + }) + + it('it returns diff of 1 month between Oct, 31 2021 and Sep, 30 2021', function () { + const result = differenceInMonths( + new Date(2021, 9 /* Oct */, 31), + new Date(2021, 8 /* Sep */, 30) + ) + assert(result === 1) + }) + + it('it returns diff of 6 month between Oct, 31 2021 and Apr, 30 2021', function () { + const result = differenceInMonths( + new Date(2021, 9 /* Oct */, 31), + new Date(2021, 3 /* Apr */, 30) + ) + assert(result === 6) + }) + + it('it returns diff of -1 month between Sep, 30 2021 and Oct, 31 2021', function () { + const result = differenceInMonths( + new Date(2021, 8 /* Sep */, 30), + new Date(2021, 9 /* Oct */, 31) + ) + assert(result === -1) + }) + + it('the difference is less than a month, but the given dates are in different calendar months', function () { + const result = differenceInMonths( + new Date(2014, 7 /* Aug */, 1), + new Date(2014, 6 /* Jul */, 31) + ) + assert(result === 0) + }) + + it('the same for the swapped dates', function () { + const result = differenceInMonths( + new Date(2014, 6 /* Jul */, 31), + new Date(2014, 7 /* Aug */, 1) + ) + assert(result === 0) + }) + + it('the days of months of the given dates are the same', function () { + const result = differenceInMonths( + new Date(2014, 8 /* Sep */, 6), + new Date(2014, 7 /* Aug */, 6) + ) + assert(result === 1) + }) + + it('the given dates are the same', function () { + const result = differenceInMonths( + new Date(2014, 8 /* Sep */, 5, 0, 0), + new Date(2014, 8 /* Sep */, 5, 0, 0) + ) + assert(result === 0) + }) + + it('does not return -0 when the given dates are the same', () => { + function isNegativeZero(x: number): boolean { + return x === 0 && 1 / x < 0 + } + + const result = differenceInMonths( + new Date(2014, 8 /* Sep */, 5, 0, 0), + new Date(2014, 8 /* Sep */, 5, 0, 0) + ) + + const resultIsNegative = isNegativeZero(result) + assert(resultIsNegative === false) + }) + }) + + it('returns NaN if the first date is `Invalid Date`', function () { + const result = differenceInMonths( + new Date(NaN), + new Date(2017, 0 /* Jan */, 1) + ) + assert(isNaN(result)) + }) + + it('returns NaN if the second date is `Invalid Date`', function () { + const result = differenceInMonths( + new Date(2017, 0 /* Jan */, 1), + new Date(NaN) + ) + assert(isNaN(result)) + }) + + it('returns NaN if the both dates are `Invalid Date`', function () { + const result = differenceInMonths(new Date(NaN), new Date(NaN)) + assert(isNaN(result)) + }) + + it('throws TypeError exception if passed less than 2 arguments', function () { + assert.throws(differenceInMonths.bind(null), TypeError) + assert.throws(differenceInMonths.bind(null, 1), TypeError) + }) + + describe('edge cases', function () { + it('returns the number of full months between the given dates - end of Feb', function () { + assert( + differenceInMonths( + new Date(2012, 1 /* Feb */, 29, 9, 0, 0), + new Date(2012, 1 /* Feb */, 29, 10, 0, 0) + ) === 0 + ) + assert( + differenceInMonths( + new Date(2012, 1 /* Feb */, 28, 9, 0, 0), + new Date(2012, 1 /* Feb */, 29, 10, 0, 0) + ) === 0 + ) + assert( + differenceInMonths( + new Date(2012, 1 /* Feb */, 27, 9, 0, 0), + new Date(2012, 1 /* Feb */, 27, 10, 0, 0) + ) === 0 + ) + assert( + differenceInMonths( + new Date(2012, 1 /* Feb */, 28, 9, 0, 0), + new Date(2012, 1 /* Feb */, 28, 10, 0, 0) + ) === 0 + ) + }) + + assert( + differenceInMonths( + new Date(2021, 1 /* Feb */, 28, 7, 23, 7), + new Date(2021, 1 /* Feb */, 28, 7, 38, 18) + ) === 0 + ) + }) +}) |