Make previousCycle explicit in signature

lib/sympto/index.js

@@ -4,8 +4,8 @@ import getPreOvulatoryPhase from './pre-ovulatory'
 import { LocalDate } from 'js-joda'
 import assert from 'assert'
 
-export default function getSymptoThermalStatus({ cycle, previousCycles = [] }) {
-  throwIfArgsAreNotInRequiredFormat([cycle, ...previousCycles])
+export default function getSymptoThermalStatus({ cycle, previousCycle, earlierCycles = [] }) {
+  throwIfArgsAreNotInRequiredFormat([cycle, ...earlierCycles])
 
   const status = {
     assumeFertility: true,
@@ -14,11 +14,10 @@ export default function getSymptoThermalStatus({ cycle, previousCycles = [] }) {
 
   // if there was no first higher measurement in the previous cycle,
   // no infertile pre-ovulatory phase may be assumed
-  const lastCycle = previousCycles[previousCycles.length - 1]
-  if (lastCycle) {
-    const statusForLast = getSymptoThermalStatus({ cycle: lastCycle })
+  if (previousCycle) {
+    const statusForLast = getSymptoThermalStatus({ cycle: previousCycle })
     if (statusForLast.temperatureShift) {
-      status.phases.preOvulatory = getPreOvulatoryPhase(cycle, previousCycles)
+      status.phases.preOvulatory = getPreOvulatoryPhase(cycle, [previousCycle, ...earlierCycles])
       if (status.phases.preOvulatory.cycleDays.length === cycle.length) {
         status.assumeFertility = false
         return status