Add `useGetTimeAgo` and utils (#4556)

* Create a testable version of ago() and re-enable the disabled test (#4364)

* Enable the test of ago()

* Use test cases

This puts the input and the expected values next to each other.

* Create dateDiff function

This is a copy of ago(), but with the ability to specify the second date instead of using Date.now().

* Let ago() use dateDiff()

* Move constants close to usage

* Test dateDiff instead of ago

This makes it possible to test the dates without being forced to rely on what the current date is.

The commented out tests do not yet pass. This is fixed in later commits.

* Update dateDiff and enable the remaining tests

* Split up tests, use date-fns as helpers

* Remove old test

* Add long format

* Add hook

* Migrate to hooks

* Delete old code

* Or equal to

* Update comment

---------

Co-authored-by: Jan Aagaard <jan@aagaard.net>

1 files changed, 102 insertions, 0 deletions

diff --git a/src/lib/hooks/__tests__/useTimeAgo.test.ts b/src/lib/hooks/__tests__/useTimeAgo.test.ts
new file mode 100644
index 000000000..e74f9c62d
--- /dev/null
+++ b/src/lib/hooks/__tests__/useTimeAgo.test.ts
@@ -0,0 +1,102 @@
+import {describe, expect, it} from '@jest/globals'
+import {MessageDescriptor} from '@lingui/core'
+import {addDays, subDays, subHours, subMinutes, subSeconds} from 'date-fns'
+
+import {dateDiff} from '../useTimeAgo'
+
+const lingui: any = (obj: MessageDescriptor) => obj.message
+
+const base = new Date('2024-06-17T00:00:00Z')
+
+describe('dateDiff', () => {
+  it(`works with numbers`, () => {
+    expect(dateDiff(subDays(base, 3), Number(base), {lingui})).toEqual('3d')
+  })
+  it(`works with strings`, () => {
+    expect(dateDiff(subDays(base, 3), base.toString(), {lingui})).toEqual('3d')
+  })
+  it(`works with dates`, () => {
+    expect(dateDiff(subDays(base, 3), base, {lingui})).toEqual('3d')
+  })
+
+  it(`equal values return now`, () => {
+    expect(dateDiff(base, base, {lingui})).toEqual('now')
+  })
+  it(`future dates return now`, () => {
+    expect(dateDiff(addDays(base, 3), base, {lingui})).toEqual('now')
+  })
+
+  it(`values < 5 seconds ago return now`, () => {
+    const then = subSeconds(base, 4)
+    expect(dateDiff(then, base, {lingui})).toEqual('now')
+  })
+  it(`values >= 5 seconds ago return seconds`, () => {
+    const then = subSeconds(base, 5)
+    expect(dateDiff(then, base, {lingui})).toEqual('5s')
+  })
+
+  it(`values < 1 min return seconds`, () => {
+    const then = subSeconds(base, 59)
+    expect(dateDiff(then, base, {lingui})).toEqual('59s')
+  })
+  it(`values >= 1 min return minutes`, () => {
+    const then = subSeconds(base, 60)
+    expect(dateDiff(then, base, {lingui})).toEqual('1m')
+  })
+  it(`minutes round down`, () => {
+    const then = subSeconds(base, 119)
+    expect(dateDiff(then, base, {lingui})).toEqual('1m')
+  })
+
+  it(`values < 1 hour return minutes`, () => {
+    const then = subMinutes(base, 59)
+    expect(dateDiff(then, base, {lingui})).toEqual('59m')
+  })
+  it(`values >= 1 hour return hours`, () => {
+    const then = subMinutes(base, 60)
+    expect(dateDiff(then, base, {lingui})).toEqual('1h')
+  })
+  it(`hours round down`, () => {
+    const then = subMinutes(base, 119)
+    expect(dateDiff(then, base, {lingui})).toEqual('1h')
+  })
+
+  it(`values < 1 day return hours`, () => {
+    const then = subHours(base, 23)
+    expect(dateDiff(then, base, {lingui})).toEqual('23h')
+  })
+  it(`values >= 1 day return days`, () => {
+    const then = subHours(base, 24)
+    expect(dateDiff(then, base, {lingui})).toEqual('1d')
+  })
+  it(`days round down`, () => {
+    const then = subHours(base, 47)
+    expect(dateDiff(then, base, {lingui})).toEqual('1d')
+  })
+
+  it(`values < 30 days return days`, () => {
+    const then = subDays(base, 29)
+    expect(dateDiff(then, base, {lingui})).toEqual('29d')
+  })
+  it(`values >= 30 days return months`, () => {
+    const then = subDays(base, 30)
+    expect(dateDiff(then, base, {lingui})).toEqual('1mo')
+  })
+  it(`months round down`, () => {
+    const then = subDays(base, 59)
+    expect(dateDiff(then, base, {lingui})).toEqual('1mo')
+  })
+  it(`values are rounded by increments of 30`, () => {
+    const then = subDays(base, 61)
+    expect(dateDiff(then, base, {lingui})).toEqual('2mo')
+  })
+
+  it(`values < 360 days return months`, () => {
+    const then = subDays(base, 359)
+    expect(dateDiff(then, base, {lingui})).toEqual('11mo')
+  })
+  it(`values >= 360 days return the earlier value`, () => {
+    const then = subDays(base, 360)
+    expect(dateDiff(then, base, {lingui})).toEqual(then.toLocaleDateString())
+  })
+})