update

node_modules/luxon/src/impl/diff.js

@@ -0,0 +1,79 @@
+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],
+    ["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 = {};
+  let lowestOrder, highWater;
+
+  for (const [unit, differ] of differs) {
+    if (units.indexOf(unit) >= 0) {
+      lowestOrder = unit;
+
+      let delta = differ(cursor, later);
+      highWater = cursor.plus({ [unit]: delta });
+
+      if (highWater > later) {
+        cursor = cursor.plus({ [unit]: delta - 1 });
+        delta -= 1;
+      } else {
+        cursor = highWater;
+      }
+
+      results[unit] = delta;
+    }
+  }
+
+  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(Object.assign(results, opts));
+
+  if (lowerOrderUnits.length > 0) {
+    return Duration.fromMillis(remainingMillis, opts)
+      .shiftTo(...lowerOrderUnits)
+      .plus(duration);
+  } else {
+    return duration;
+  }
+}