Merge pull request #249 from github/tweak-rounding-rules-for-months

tweak rounding rules for months
github · Feb 7, 2023 · 244af66 · 244af66
2 parents cce3194 + d39c73e
commit 244af66
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Showing 3 changed files with 94 additions and 41 deletions.
diff --git a/src/duration.ts b/src/duration.ts
@@ -150,20 +150,29 @@ export function roundToSingleUnit(duration: Duration, {relativeTo = Date.now()}:
   if (hours >= 21) days += Math.round(hours / 24)
   if (days || weeks || months || years) hours = 0
 
+  const currentYear = relativeTo.getFullYear()
+  let currentMonth = relativeTo.getMonth()
+  const currentDate = relativeTo.getDate()
+  if (days >= 27 || (years + months && days)) {
+    relativeTo.setDate(currentDate + days * sign)
+    days = 0
+    months += Math.abs(
+      relativeTo.getFullYear() >= currentYear
+        ? relativeTo.getMonth() - currentMonth
+        : relativeTo.getMonth() - currentMonth - 12,
+    )
+    currentMonth = relativeTo.getMonth()
+  }
+
   if (days >= 6) weeks += Math.round(days / 7)
   if (weeks || months || years) days = 0
 
   if (weeks >= 4) months += Math.round(weeks / 4)
   if (months || years) weeks = 0
 
-  const currentMonth = relativeTo.getMonth()
-  const delta = sign < 0 ? currentMonth : 12 - currentMonth
-  if (months && months >= delta) {
-    years += 1
-    relativeTo.setFullYear(relativeTo.getFullYear() + sign)
-    relativeTo.setMonth(0)
-    months -= delta
-    years += Math.floor(months / 12)
+  if (months >= 11 || (years && months)) {
+    relativeTo.setMonth(relativeTo.getMonth() + months * sign)
+    years += Math.abs(currentYear - relativeTo.getFullYear())
   }
   if (years) months = 0
 

diff --git a/test/duration.ts b/test/duration.ts
@@ -235,41 +235,72 @@ suite('duration', function () {
       ['PT1H55M', 'PT2H'],
       ['PT20H', 'PT20H'],
       ['PT21H', 'P1D'],
-      ['P4D', 'P4D'],
-      ['P6D', 'P1W'],
-      ['P2W', 'P2W'],
-      ['P3W3D', 'P3W'],
-      ['P3W6D', 'P1M'],
-      ['P21D', 'P3W'],
-      ['P24D', 'P3W'],
-      ['P24DT25H', 'P1M'],
-      ['P25D', 'P1M'],
-      ['P1M1D', 'P1M'],
+      ['P4D', 'P4D', {relativeTo: new Date('2023-07-01T00:00:00')}],
+      ['-P4D', '-P4D', {relativeTo: new Date('2023-07-01T00:00:00')}],
+      ['P6D', 'P1W', {relativeTo: new Date('2023-07-01T00:00:00')}],
+      ['-P6D', '-P1W', {relativeTo: new Date('2023-07-01T00:00:00')}],
+      ['P2W', 'P2W', {relativeTo: new Date('2023-07-01T00:00:00')}],
+      ['-P2W', '-P2W', {relativeTo: new Date('2023-07-01T00:00:00')}],
+      ['P3W3D', 'P3W', {relativeTo: new Date('2023-07-01T00:00:00')}],
+      ['-P3W3D', '-P3W', {relativeTo: new Date('2023-07-01T00:00:00')}],
+      ['P3W6D', 'P1M', {relativeTo: new Date('2023-07-01T00:00:00')}],
+      ['-P3W6D', '-P1M', {relativeTo: new Date('2023-07-01T00:00:00')}],
+      ['P21D', 'P3W', {relativeTo: new Date('2023-07-01T00:00:00')}],
+      ['-P21D', '-P3W', {relativeTo: new Date('2023-07-01T00:00:00')}],
+      ['P24D', 'P3W', {relativeTo: new Date('2023-07-01T00:00:00')}],
+      ['-P24D', '-P3W', {relativeTo: new Date('2023-07-01T00:00:00')}],
+      ['P24DT25H', 'P1M', {relativeTo: new Date('2023-07-01T00:00:00')}],
+      ['-P24DT25H', '-P1M', {relativeTo: new Date('2023-07-01T00:00:00')}],
+      ['P25D', 'P1M', {relativeTo: new Date('2023-07-01T00:00:00')}],
+      ['-P25D', '-P1M', {relativeTo: new Date('2023-07-01T00:00:00')}],
+      ['P1M1D', 'P1M', {relativeTo: new Date('2023-07-02T00:00:00')}],
+      ['-P1M1D', '-P1M', {relativeTo: new Date('2023-07-02T00:00:00')}],
+      ['P1M1D', 'P2M', {relativeTo: new Date('2023-07-31T00:00:00')}],
+      ['-P1M1D', '-P2M', {relativeTo: new Date('2023-07-01T00:00:00')}],
+      ['P1D', 'P1D', {relativeTo: new Date('2022-01-01T00:00:00Z')}],
       ['-P1D', '-P1D', {relativeTo: new Date('2022-01-01T00:00:00Z')}],
       ['P8M', 'P8M', {relativeTo: new Date('2022-01-01T00:00:00Z')}],
       ['-P8M', '-P8M', {relativeTo: new Date('2022-10-01T00:00:00Z')}],
       ['P9M', 'P9M', {relativeTo: new Date('2022-01-01T00:00:00Z')}],
       ['-P9M', '-P9M', {relativeTo: new Date('2022-11-01T00:00:00Z')}],
-      ['-P1M', '-P1Y', {relativeTo: new Date('2023-01-01T00:00:00Z')}],
-      ['P1M', 'P1Y', {relativeTo: new Date('2023-12-01T00:00:00Z')}],
+      ['P1M', 'P1M', {relativeTo: new Date('2023-12-01T00:00:00Z')}],
+      ['-P1M', '-P1M', {relativeTo: new Date('2023-01-01T00:00:00Z')}],
+      ['P1M15D', 'P1M', {relativeTo: new Date('2023-12-01T00:00:00Z')}],
+      ['-P1M15D', '-P2M', {relativeTo: new Date('2023-01-01T00:00:00Z')}],
+      ['P1M15D', 'P2M', {relativeTo: new Date('2023-01-18T00:00:00Z')}],
+      ['-P1M15D', '-P2M', {relativeTo: new Date('2023-01-01T00:00:00Z')}],
+      ['P1M15D', 'P2M', {relativeTo: new Date('2023-01-18T00:00:00Z')}],
       ['-P18M', '-P2Y', {relativeTo: new Date('2023-01-01T00:00:00Z')}],
       ['P18M', 'P2Y', {relativeTo: new Date('2023-12-01T00:00:00Z')}],
-      ['-P18M', '-P2Y', {relativeTo: new Date('2023-07-01T00:00:00Z')}],
+      ['-P18M', '-P1Y', {relativeTo: new Date('2023-07-01T00:00:00Z')}],
       ['P18M', 'P2Y', {relativeTo: new Date('2023-07-01T00:00:00Z')}],
       ['-P18M', '-P1Y', {relativeTo: new Date('2023-08-01T00:00:00Z')}],
       ['P18M', 'P1Y', {relativeTo: new Date('2023-03-01T00:00:00Z')}],
-      ['-P9M20DT25H', '-P9M', {relativeTo: new Date('2023-11-12T00:00:00Z')}],
-      ['P9M20DT25H', 'P9M', {relativeTo: new Date('2023-01-12T00:00:00Z')}],
+      [
+        '-P9M20DT25H',
+        '-P10M',
+        {
+          relativeTo: new Date('2023-11-12T00:00:00Z'),
+        },
+      ],
+      ['P9M20DT25H', 'P10M', {relativeTo: new Date('2023-01-12T00:00:00Z')}],
       ['P11M', 'P1Y', {relativeTo: new Date('2022-11-01T00:00:00Z')}],
       ['-P11M', '-P1Y', {relativeTo: new Date('2022-11-01T00:00:00Z')}],
       ['P1Y4D', 'P1Y', {relativeTo: new Date('2022-11-01T00:00:00Z')}],
       ['P1Y5M13D', 'P1Y', {relativeTo: new Date('2023-01-01T00:00:00Z')}],
       ['P1Y5M15D', 'P1Y', {relativeTo: new Date('2023-01-01T00:00:00Z')}],
       ['P1Y5M20D', 'P1Y', {relativeTo: new Date('2023-01-01T00:00:00Z')}],
       ['P1Y10M', 'P2Y', {relativeTo: new Date('2022-11-01T00:00:00Z')}],
-      ['-P1Y10M', '-P2Y', {relativeTo: new Date('2022-11-01T00:00:00Z')}],
+      ['-P1Y10M', '-P1Y', {relativeTo: new Date('2022-11-01T00:00:00Z')}],
       ['P1Y10M', 'P1Y', {relativeTo: new Date('2022-01-01T00:00:00Z')}],
       ['-P1Y10M', '-P1Y', {relativeTo: new Date('2022-12-01T00:00:00Z')}],
+      [
+        '-P1Y5M20D',
+        '-P2Y',
+        {
+          relativeTo: new Date('2022-01-01T00:00:00Z'),
+        },
+      ],
     ])
     for (const [input, expected, opts] of roundTests) {
       test(`roundToSingleUnit(${input}) === ${expected}`, () => {
@@ -299,16 +330,29 @@ suite('duration', function () {
       ['PT1H31M', [1, 'hour']],
       ['PT1H55M', [2, 'hour']],
       ['PT20H', [20, 'hour']],
-      ['PT21H', [1, 'day']],
-      ['P4D', [4, 'day']],
-      ['P6D', [1, 'week']],
-      ['P2W', [2, 'week']],
-      ['P3W3D', [3, 'week']],
-      ['P3W6D', [1, 'month']],
-      ['P21D', [3, 'week']],
-      ['P24D', [3, 'week']],
-      ['P24DT25H', [1, 'month']],
-      ['P25D', [1, 'month']],
+      ['PT21H', [1, 'day'], {relativeTo: '2023-01-15T00:00:00Z'}],
+      ['-PT21H', [-1, 'day'], {relativeTo: '2023-01-15T00:00:00Z'}],
+      ['P4D', [4, 'day'], {relativeTo: '2023-01-15T00:00:00Z'}],
+      ['-P4D', [-4, 'day'], {relativeTo: '2023-01-15T00:00:00Z'}],
+      ['P6D', [1, 'week'], {relativeTo: '2023-01-15T00:00:00Z'}],
+      ['-P6D', [-1, 'week'], {relativeTo: '2023-01-15T00:00:00Z'}],
+      ['P2W', [2, 'week'], {relativeTo: '2023-01-15T00:00:00Z'}],
+      ['-P2W', [-2, 'week'], {relativeTo: '2023-01-15T00:00:00Z'}],
+      ['P3W3D', [3, 'week'], {relativeTo: '2023-01-15T00:00:00Z'}],
+      ['-P3W3D', [-3, 'week'], {relativeTo: '2023-01-15T00:00:00Z'}],
+      ['P3W6D', [1, 'month'], {relativeTo: '2023-01-15T00:00:00Z'}],
+      ['-P3W6D', [-1, 'month'], {relativeTo: '2023-01-15T00:00:00Z'}],
+      ['P21D', [3, 'week'], {relativeTo: '2023-01-01T00:00:00Z'}],
+      ['-P21D', [-3, 'week'], {relativeTo: '2023-01-01T00:00:00Z'}],
+      ['P24D', [3, 'week'], {relativeTo: '2023-01-01T00:00:00Z'}],
+      ['-P24D', [-3, 'week'], {relativeTo: '2023-01-01T00:00:00Z'}],
+      ['P24DT25H', [1, 'month'], {relativeTo: '2023-01-15T00:00:00Z'}],
+      ['P25D', [1, 'month'], {relativeTo: '2023-01-15T00:00:00Z'}],
+      ['-P35D', [-1, 'month'], {relativeTo: '2023-02-07T22:22:57Z'}],
+      ['-P45D', [-1, 'month'], {relativeTo: '2023-02-17T22:22:57Z'}],
+      ['-P55D', [-1, 'month'], {relativeTo: '2023-02-27T22:22:57Z'}],
+      ['-P65D', [-3, 'month'], {relativeTo: '2023-02-28T22:22:57Z'}],
+      ['-P75D', [-3, 'month'], {relativeTo: '2023-03-09T22:22:57Z'}],
       [
         'P8M',
         [8, 'month'],
@@ -337,7 +381,7 @@ suite('duration', function () {
           relativeTo: new Date('2022-12-01T00:00:00Z'),
         },
       ],
-      ['P1M1D', [1, 'month']],
+      ['P1M1D', [1, 'month'], {relativeTo: new Date('2022-12-01T00:00:00Z')}],
       [
         'P9M20DT25H',
         [9, 'month'],
@@ -347,14 +391,14 @@ suite('duration', function () {
       ],
       [
         '-P9M20DT25H',
-        [-9, 'month'],
+        [-10, 'month'],
         {
           relativeTo: new Date('2022-12-01T00:00:00Z'),
         },
       ],
       [
         'P9M24DT25H',
-        [10, 'month'],
+        [9, 'month'],
         {
           relativeTo: new Date('2022-01-01T00:00:00Z'),
         },

diff --git a/test/relative-time.js b/test/relative-time.js
@@ -471,7 +471,7 @@ suite('relative-time', function () {
       time.setAttribute('tense', 'past')
       time.setAttribute('datetime', '2023-06-01T00:00:00Z')
       await Promise.resolve()
-      assert.equal(time.shadowRoot.textContent, '3 months ago')
+      assert.equal(time.shadowRoot.textContent, '4 months ago')
     })
 
     test('micro formats years', async () => {
@@ -1174,7 +1174,7 @@ suite('relative-time', function () {
         datetime: '2022-12-03T15:46:00.000Z',
         tense: 'future',
         format: 'relative',
-        expected: 'next month',
+        expected: 'in 2 months',
       },
       {
         datetime: '2022-12-03T15:46:00.000Z',
@@ -2408,14 +2408,14 @@ suite('relative-time', function () {
         datetime: '2024-03-01T12:00:00.000Z',
         tense: 'future',
         format: 'auto',
-        expected: 'in 2 years',
+        expected: 'in 3 years',
       },
       {
         reference: '2022-12-31T12:00:00.000Z',
         datetime: '2024-03-01T12:00:00.000Z',
         tense: 'future',
         format: 'micro',
-        expected: '2y',
+        expected: '3y',
       },
       {
         reference: '2021-04-24T12:00:00.000Z',