Add isMensesStart

lib/cycle.js

@@ -133,6 +133,25 @@ export default function config(opts) {
     }
   }
 
+  function isMensesStart(cycleDay) {
+    if (!cycleDay.bleeding || cycleDay.bleeding.exclude) return false
+    const bleedingDays = bleedingDaysSortedByDate
+    if (noBleedingDayWithinThreshold(cycleDay)) {
+      return true
+    }
+    return false
+
+    function noBleedingDayWithinThreshold(day) {
+      const localDate = LocalDate.parse(day.date)
+      const threshold = localDate.minusDays(maxBreakInBleeding + 1).toString()
+      const index = bleedingDays.findIndex(day => day.date === cycleDay.date)
+      const previousBleedingDays = bleedingDays.slice(index + 1)
+      return !previousBleedingDays.some(day => {
+        return day.date >= threshold && !day.bleeding.exclude
+      })
+    }
+  }
+
   function getCycleLength(cycleStartDates) {
     const cycleLengths = []
     for (let i = 0; i < cycleStartDates.length - 1; i++) {
@@ -188,6 +207,7 @@ export default function config(opts) {
     getCyclesBefore,
     getAllMensesStarts,
     getCycleLength,
-    getPredictedMenses
+    getPredictedMenses,
+    isMensesStart
   }
 }
\ No newline at end of file

test/cycle.spec.js

@@ -685,4 +685,146 @@ describe('getAllMensesStart', () => {
     expect(result.length).to.eql(500)
     expect(duration).to.be.lessThan(100)
   })
+})
+
+describe('isMensesStart', () => {
+  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 { isMensesStart } = cycleModule({
+      cycleDaysSortedByDate,
+      bleedingDaysSortedByDate: cycleDaysSortedByDate.filter(d => d.bleeding)
+    })
+    const start = isMensesStart(cycleDaysSortedByDate[3])
+    expect(start).to.be.true()
+    expect(isMensesStart(cycleDaysSortedByDate[0])).to.be.false()
+    expect(isMensesStart(cycleDaysSortedByDate[1])).to.be.false()
+    expect(isMensesStart(cycleDaysSortedByDate[2])).to.be.false()
+    expect(isMensesStart(cycleDaysSortedByDate[4])).to.be.false()
+  })
+
+  it('works with previous excluded value', () => {
+    const cycleDaysSortedByDate = [
+      {
+        date: '2018-06-01',
+        bleeding: { value: 2 }
+      },
+      {
+        date: '2018-05-01',
+        bleeding: { value: 2 }
+      },
+      {
+        date: '2018-04-30',
+        bleeding: { value: 2 , exclude: true}
+      },
+    ]
+
+    const { isMensesStart } = cycleModule({
+      cycleDaysSortedByDate,
+      bleedingDaysSortedByDate: cycleDaysSortedByDate.filter(d => d.bleeding)
+    })
+    const start = isMensesStart(cycleDaysSortedByDate[1])
+    expect(start).to.be.true()
+    const notStart = isMensesStart(cycleDaysSortedByDate[2])
+    expect(notStart).to.be.false()
+  })
+
+  it('returns false when day has no bleeding', () => {
+    const cycleDaysSortedByDate = [
+      {
+        date: '2018-06-01',
+      },
+      {
+        date: '2018-05-01',
+      },
+      {
+        date: '2018-04-30',
+        bleeding: { value: 2 , exclude: true}
+      },
+    ]
+
+    const { isMensesStart } = cycleModule({
+      cycleDaysSortedByDate,
+      bleedingDaysSortedByDate: cycleDaysSortedByDate.filter(d => d.bleeding)
+    })
+    const start = isMensesStart(cycleDaysSortedByDate[0])
+    expect(start).to.be.false()
+  })
+
+  it('returns false when there is a previous bleeding day within the threshold', () => {
+    const cycleDaysSortedByDate = [
+      {
+        date: '2018-06-01',
+      },
+      {
+        date: '2018-05-01',
+      },
+      {
+        date: '2018-04-30',
+        bleeding: { value: 2 }
+      },
+      {
+        date: '2018-04-29'
+      },
+      {
+        date: '2018-04-28',
+        bleeding: { value: 2 }
+      },
+    ]
+
+    const { isMensesStart } = cycleModule({
+      cycleDaysSortedByDate,
+      bleedingDaysSortedByDate: cycleDaysSortedByDate.filter(d => d.bleeding)
+    })
+    const start = isMensesStart(cycleDaysSortedByDate[2])
+    expect(start).to.be.false()
+  })
+
+  it('returns true when there is a previous excluded bleeding day within the threshold', () => {
+    const cycleDaysSortedByDate = [
+      {
+        date: '2018-06-01',
+      },
+      {
+        date: '2018-05-01',
+      },
+      {
+        date: '2018-04-30',
+        bleeding: { value: 2 }
+      },
+      {
+        date: '2018-04-29'
+      },
+      {
+        date: '2018-04-28',
+        bleeding: { value: 2 , exclude: true}
+      },
+    ]
+
+    const { isMensesStart } = cycleModule({
+      cycleDaysSortedByDate,
+      bleedingDaysSortedByDate: cycleDaysSortedByDate.filter(d => d.bleeding)
+    })
+    const start = isMensesStart(cycleDaysSortedByDate[2])
+    expect(start).to.be.true()
+  })
 })
\ No newline at end of file