Add getMensesDaysAfter

lib/cycle.js

@@ -135,23 +135,45 @@ export default function config(opts) {
 
   function isMensesStart(cycleDay) {
     if (!cycleDay.bleeding || cycleDay.bleeding.exclude) return false
-    const bleedingDays = bleedingDaysSortedByDate
-    if (noBleedingDayWithinThreshold(cycleDay)) {
-      return true
-    }
+    if (noBleedingDayWithinThresholdBefore(cycleDay)) return true
     return false
 
-    function noBleedingDayWithinThreshold(day) {
-      const localDate = LocalDate.parse(day.date)
+    function noBleedingDayWithinThresholdBefore(cycleDay) {
+      const localDate = LocalDate.parse(cycleDay.date)
       const threshold = localDate.minusDays(maxBreakInBleeding + 1).toString()
+      const bleedingDays = bleedingDaysSortedByDate
       const index = bleedingDays.findIndex(day => day.date === cycleDay.date)
-      const previousBleedingDays = bleedingDays.slice(index + 1)
-      return !previousBleedingDays.some(day => {
+      const candidates = bleedingDays.slice(index + 1)
+      return !candidates.some(day => {
         return day.date >= threshold && !day.bleeding.exclude
       })
     }
   }
 
+  function getMensesDaysAfter(bleedingDay) {
+    const bleedingDays = bleedingDaysSortedByDate.filter(d => {
+      return !d.bleeding.exclude
+    })
+    const startIndex = bleedingDays.findIndex(day => {
+      return day.date === bleedingDay.date
+    })
+    return recurse(bleedingDay, startIndex, [])
+
+    function recurse(day, i, mensesDays) {
+      if (i === 0) return mensesDays
+      const next = bleedingDays[i - 1]
+      if (!isWithinThreshold(day, next)) return mensesDays
+      mensesDays.unshift(next)
+      return recurse(next, i - 1, mensesDays)
+    }
+
+    function isWithinThreshold(cycleDay, nextCycleDay) {
+      const localDate = LocalDate.parse(cycleDay.date)
+      const threshold = localDate.plusDays(maxBreakInBleeding + 1).toString()
+      return nextCycleDay.date <= threshold
+    }
+  }
+
   function getCycleLength(cycleStartDates) {
     const cycleLengths = []
     for (let i = 0; i < cycleStartDates.length - 1; i++) {
@@ -208,6 +230,7 @@ export default function config(opts) {
     getAllMensesStarts,
     getCycleLength,
     getPredictedMenses,
-    isMensesStart
+    isMensesStart,
+    getMensesDaysAfter
   }
 }

test/cycle.spec.js

@@ -827,4 +827,176 @@ describe('isMensesStart', () => {
     const start = isMensesStart(cycleDaysSortedByDate[2])
     expect(start).to.be.true()
   })
+})
+
+describe('getMensesDaysAfter', () => {
+  it('works for simple menses start', () => {
+    const cycleDaysSortedByDate = [
+      {
+        date: '2018-05-04',
+      },
+      {
+        date: '2018-05-03',
+        bleeding: { value: 1 }
+      },
+      {
+        date: '2018-05-02',
+        bleeding: { value: 1 }
+      },
+      {
+        date: '2018-05-01',
+        bleeding: { value: 1 }
+      },
+      {
+        date: '2018-04-30',
+      }
+    ]
+
+    const { getMensesDaysAfter } = cycleModule({
+      cycleDaysSortedByDate,
+      bleedingDaysSortedByDate: cycleDaysSortedByDate.filter(d => d.bleeding)
+    })
+    const days = getMensesDaysAfter(cycleDaysSortedByDate[3])
+    expect(days).to.eql([
+      {
+        date: '2018-05-03',
+        bleeding: { value: 1 }
+      },
+      {
+        date: '2018-05-02',
+        bleeding: { value: 1 }
+      }
+    ])
+  })
+
+  it('ignores excluded values', () => {
+    const cycleDaysSortedByDate = [
+      {
+        date: '2018-05-04',
+      },
+      {
+        date: '2018-05-03',
+        bleeding: { value: 1 }
+      },
+      {
+        date: '2018-05-02',
+        bleeding: { value: 1, exclude: true }
+      },
+      {
+        date: '2018-05-01',
+        bleeding: { value: 1 }
+      },
+      {
+        date: '2018-04-30',
+      }
+    ]
+
+    const { getMensesDaysAfter } = cycleModule({
+      cycleDaysSortedByDate,
+      bleedingDaysSortedByDate: cycleDaysSortedByDate.filter(d => d.bleeding)
+    })
+    const days = getMensesDaysAfter(cycleDaysSortedByDate[3])
+    expect(days).to.eql([
+      {
+        date: '2018-05-03',
+        bleeding: { value: 1 }
+      }
+    ])
+  })
+
+  it('returns empty when there are no bleeding days after', () => {
+    const cycleDaysSortedByDate = [
+      {
+        date: '2018-05-04',
+      },
+      {
+        date: '2018-05-03',
+      },
+      {
+        date: '2018-05-02',
+      },
+      {
+        date: '2018-05-01',
+        bleeding: { value: 1 }
+      },
+      {
+        date: '2018-04-30',
+      }
+    ]
+
+    const { getMensesDaysAfter } = cycleModule({
+      cycleDaysSortedByDate,
+      bleedingDaysSortedByDate: cycleDaysSortedByDate.filter(d => d.bleeding)
+    })
+    const days = getMensesDaysAfter(cycleDaysSortedByDate[3])
+    expect(days).to.eql([])
+  })
+
+  it('returns empty when there are no bleeding days within threshold', () => {
+    const cycleDaysSortedByDate = [
+      {
+        date: '2018-05-04',
+        bleeding: { value: 1 }
+      },
+      {
+        date: '2018-05-03',
+      },
+      {
+        date: '2018-05-02',
+      },
+      {
+        date: '2018-05-01',
+        bleeding: { value: 1 }
+      },
+      {
+        date: '2018-04-30',
+      }
+    ]
+
+    const { getMensesDaysAfter } = cycleModule({
+      cycleDaysSortedByDate,
+      bleedingDaysSortedByDate: cycleDaysSortedByDate.filter(d => d.bleeding)
+    })
+    const days = getMensesDaysAfter(cycleDaysSortedByDate[3])
+    expect(days).to.eql([])
+  })
+
+  it('includes days within the treshold', () => {
+    const cycleDaysSortedByDate = [
+      {
+        date: '2018-05-04',
+      },
+      {
+        date: '2018-05-05',
+        bleeding: { value: 1 }
+      },
+      {
+        date: '2018-05-03',
+        bleeding: { value: 1 }
+      },
+      {
+        date: '2018-05-01',
+        bleeding: { value: 1 }
+      },
+      {
+        date: '2018-04-30',
+      }
+    ]
+
+    const { getMensesDaysAfter } = cycleModule({
+      cycleDaysSortedByDate,
+      bleedingDaysSortedByDate: cycleDaysSortedByDate.filter(d => d.bleeding)
+    })
+    const days = getMensesDaysAfter(cycleDaysSortedByDate[3])
+    expect(days).to.eql([
+      {
+        date: '2018-05-05',
+        bleeding: { value: 1 }
+      },
+      {
+        date: '2018-05-03',
+        bleeding: { value: 1 }
+      }
+    ])
+  })
 })