Merge pull request #23 from nshiab/add-humidex

update getHumidex for humidex < temperature

Author: nshiab

src/weather/getHumidex.ts

@@ -1,5 +1,6 @@
 /**
- * Calculate Humidex Factor in Celsius given the temperature in Celsius and humidity percentage
+ * Calculate Humidex Factor in Celsius given the temperature in Celsius and humidity percentage.
+ * In case the calculated humidex is less than the given temperature, it returns temperature itself.
  * ```js
  * const humidex = getHumidex(30, 70); // returns 41
  * ```
@@ -23,5 +24,6 @@ export default function getHumidex(
     const eTd = (eTs * humidity) / 100
     const humidex = Math.round(temperature + ((eTd - 10) * 5) / 9)
 
+    if (humidex < temperature) return temperature
     return humidex
 }

test/weather/getHumidex.test.ts

@@ -2,22 +2,26 @@ import assert from "assert"
 import getHumidex from "../../src/weather/getHumidex.js"
 
 describe("getHumidex", () => {
-    it("should return the humidex (41) given temperature (30 C) and humidity (%70)", () => {
+    it("should return the humidex (41) given temperature (30 C) and humidity (70%)", () => {
         const humidex = getHumidex(30, 70)
         assert.equal(humidex, 41)
     })
-    it("should return the humidex (29) given temperature (21 C) and humidity (%100)", () => {
+    it("should return the humidex (29) given temperature (21 C) and humidity (100%)", () => {
         const humidex = getHumidex(21, 100)
         assert.equal(humidex, 29)
     })
-    it("should return the humidex (47) given temperature (43 C) and humidity (%20)", () => {
+    it("should return the humidex (47) given temperature (43 C) and humidity (20%)", () => {
         const humidex = getHumidex(43, 20)
         assert.equal(humidex, 47)
     })
-    it("should return the humidex (59) given temperature (35 C) and humidity (%95)", () => {
+    it("should return the humidex (59) given temperature (35 C) and humidity (95%)", () => {
         const humidex = getHumidex(35, 95)
         assert.equal(humidex, 59)
     })
+    it("should return the temperature (21 C) (with humidity (20%)) if humidex is less than the temperature", () => {
+        const humidex = getHumidex(21, 20)
+        assert.equal(humidex, 21)
+    })
     it("should throw error when humidex is not between 0 and 100", () => {
         assert.throws(() => getHumidex(30, 105))
     })