For temperature, add 2 passing test for simple happy path

lib/sensiplan.js

@@ -0,0 +1,39 @@
+function getTemperatureStatus(targetDateString, previousDaysInCycle) {
+  const tempValues = previousDaysInCycle
+    .filter(day => day.temperature)
+    .map(day => !day.temperature.exclude && rounded(day.temperature.value, 0.05))
+
+  return tempValues.reduce((acc, curr) => {
+    // if we don't yet have 6 lower temps, we just collect
+    // if no shift has been detected, we collect low temps
+    // after the shift has been detected, we count them as part
+    // of the higher temperature phase
+    if (acc.low.length < 6 || (!acc.shiftDetected && curr <= acc.ltl)) {
+      acc.low.push(curr)
+      acc.ltl = Math.max(...acc.low.slice(-6))
+    } else {
+      acc.high.push(curr)
+    }
+
+    // we round the difference because of JS decimal weirdness
+    if (acc.high.length === 3 && rounded(curr - acc.ltl, 0.01) >= 0.2) {
+      acc.shiftDetected = true
+    }
+
+    return acc
+  }, {
+    low: [],
+    high: [],
+    ltl: null,
+    shiftDetected: false
+  })
+}
+
+function rounded(val, step) {
+  const inverted = 1 / step
+  return Math.round(val * inverted) / inverted
+}
+
+export {
+  getTemperatureStatus
+}

lib/sensiplan/index.js

@@ -1,7 +0,0 @@
-function getTemperatureStatus (targetDate) {
-  return '42'
-}
-
-export {
-  getTemperatureStatus
-}