Throw if args are wrong

lib/sympto/index.js

@@ -4,7 +4,8 @@ import getPreOvulatoryPhase from './pre-ovulatory'
 import { LocalDate } from 'js-joda'
 
 export default function ({ cycle, previousCycle }) {
-  // TODO check for basic stuff, throw if nonexistent
+  throwIfArgsAreNotInRequiredFormat(cycle, previousCycle)
+
   const status = {
     assumeFertility: true,
     phases: {}
@@ -66,4 +67,26 @@ export default function ({ cycle, previousCycle }) {
   status.assumeFertility = false
 
   return status
+}
+
+function throwIfArgsAreNotInRequiredFormat(cycle, previousCycle) {
+  if (!Array.isArray(cycle) || !cycle.length) throw new Error('Please provide all cycle days as array')
+  if (!Array.isArray(previousCycle) || !previousCycle.length) throw new Error('Please provide previous cycle days as array')
+  if (
+    !cycle[0].bleeding || typeof cycle[0].bleeding.value != 'number' ||
+    !previousCycle[0].bleeding || typeof previousCycle[0].bleeding.value != 'number'
+  ) throw new Error('Cycle must start with bleeding')
+
+  if ([cycle, previousCycle].some(cycle => {
+    return cycle.some(day => {
+      if (!day.date) return true
+      try {
+        LocalDate.parse(day.date)
+      } catch(err) {
+        throw new Error('Please provide dates in ISO8601 format')
+      }
+      if (day.temperature && typeof day.temperature.value != 'number') return true
+      if (day.mucus && typeof day.mucus.value != 'number') return true
+    })
+  })) throw new Error('Cycle days are not in correct format')
 }