summaryrefslogtreecommitdiff
path: root/node_modules/luxon/src/impl/diff.js
diff options
context:
space:
mode:
authorShipwreckt <me@shipwreckt.co.uk>2025-10-31 20:02:14 +0000
committerShipwreckt <me@shipwreckt.co.uk>2025-10-31 20:02:14 +0000
commit7a52ddeba2a68388b544f529d2d92104420f77b0 (patch)
tree15ddd47457a2cb4a96060747437d36474e4f6b4e /node_modules/luxon/src/impl/diff.js
parent53d6ae2b5568437afa5e4995580a3fb679b7b91b (diff)
Changed from static to 11ty!
Diffstat (limited to 'node_modules/luxon/src/impl/diff.js')
-rw-r--r--node_modules/luxon/src/impl/diff.js95
1 files changed, 95 insertions, 0 deletions
diff --git a/node_modules/luxon/src/impl/diff.js b/node_modules/luxon/src/impl/diff.js
new file mode 100644
index 0000000..ebd129e
--- /dev/null
+++ b/node_modules/luxon/src/impl/diff.js
@@ -0,0 +1,95 @@
+import Duration from "../duration.js";
+
+function dayDiff(earlier, later) {
+ const utcDayStart = (dt) => dt.toUTC(0, { keepLocalTime: true }).startOf("day").valueOf(),
+ ms = utcDayStart(later) - utcDayStart(earlier);
+ return Math.floor(Duration.fromMillis(ms).as("days"));
+}
+
+function highOrderDiffs(cursor, later, units) {
+ const differs = [
+ ["years", (a, b) => b.year - a.year],
+ ["quarters", (a, b) => b.quarter - a.quarter + (b.year - a.year) * 4],
+ ["months", (a, b) => b.month - a.month + (b.year - a.year) * 12],
+ [
+ "weeks",
+ (a, b) => {
+ const days = dayDiff(a, b);
+ return (days - (days % 7)) / 7;
+ },
+ ],
+ ["days", dayDiff],
+ ];
+
+ const results = {};
+ const earlier = cursor;
+ let lowestOrder, highWater;
+
+ /* This loop tries to diff using larger units first.
+ If we overshoot, we backtrack and try the next smaller unit.
+ "cursor" starts out at the earlier timestamp and moves closer and closer to "later"
+ as we use smaller and smaller units.
+ highWater keeps track of where we would be if we added one more of the smallest unit,
+ this is used later to potentially convert any difference smaller than the smallest higher order unit
+ into a fraction of that smallest higher order unit
+ */
+ for (const [unit, differ] of differs) {
+ if (units.indexOf(unit) >= 0) {
+ lowestOrder = unit;
+
+ results[unit] = differ(cursor, later);
+ highWater = earlier.plus(results);
+
+ if (highWater > later) {
+ // we overshot the end point, backtrack cursor by 1
+ results[unit]--;
+ cursor = earlier.plus(results);
+
+ // if we are still overshooting now, we need to backtrack again
+ // this happens in certain situations when diffing times in different zones,
+ // because this calculation ignores time zones
+ if (cursor > later) {
+ // keep the "overshot by 1" around as highWater
+ highWater = cursor;
+ // backtrack cursor by 1
+ results[unit]--;
+ cursor = earlier.plus(results);
+ }
+ } else {
+ cursor = highWater;
+ }
+ }
+ }
+
+ return [cursor, results, highWater, lowestOrder];
+}
+
+export default function (earlier, later, units, opts) {
+ let [cursor, results, highWater, lowestOrder] = highOrderDiffs(earlier, later, units);
+
+ const remainingMillis = later - cursor;
+
+ const lowerOrderUnits = units.filter(
+ (u) => ["hours", "minutes", "seconds", "milliseconds"].indexOf(u) >= 0
+ );
+
+ if (lowerOrderUnits.length === 0) {
+ if (highWater < later) {
+ highWater = cursor.plus({ [lowestOrder]: 1 });
+ }
+
+ if (highWater !== cursor) {
+ results[lowestOrder] = (results[lowestOrder] || 0) + remainingMillis / (highWater - cursor);
+ }
+ }
+
+ const duration = Duration.fromObject(results, opts);
+
+ if (lowerOrderUnits.length > 0) {
+ return Duration.fromMillis(remainingMillis, opts)
+ .shiftTo(...lowerOrderUnits)
+ .plus(duration);
+ } else {
+ return duration;
+ }
+}